Re: [Emc-users] changing psu in a dell dimension.

[N]

On Mon, 26 Aug 2019 12:07:42 -0700
Chris Albertson  wrote:

> Could it be that a connected but unpowered DVD looks like a broken DVD and
> the system has the DVD ahead of the hard disk in the boot order?Try
> disconnecting the data cable to the DVD.
> 
> How often do you use a DVD anymore, especially if the computer is on a tall
> shelf?  You might just remove the drive.
> 
> On Mon, Aug 26, 2019 at 11:42 AM Gene Heskett  wrote:
> 
> > Greetings all;
> >
> > I felt just froggy enough to lug a psu I had out to the garage, and
> > lugged a stepladder in to get me high enough to reach the dell I''ve
> > been running my G0704 with. Genuine  dell to non-dell.  But the darned
> > thing only has one sata power cable, so I skipped powering up the dvd in
> > it.  On bootup it claimed the cmos battery was low so I pulled the plug
> > and put a fresh 2032 in it. Nothing on screen, orange power led, goes on
> > and off like it should. ...

Could not insert the connectors was a milliter to high and did something 
similar a few days. Disassembled and remounted mother so that connector could 
be inserted. I also found a button on mother board I could resist to push.

F10 could enter bios but it was not possible to get computer to reboot again. 
Booting from DVD and reinstall however worked, I use this computer now.


Noname


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Re: [Emc-users] Mesa 8i20 as a spindle drive

[N]

Driver has some kind of input?

> Does anyone know if it would be possible to use a Mesa 8i20 for a 3 phase
> spindle motor? No encoder just for a router.
> 
> Thanks,
>Curt
> 
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Re: [Emc-users] (no subject) Position logger, sampler?

[N]

Not sure what position_logger.cc is and do not find the file then searching but 
myself used sampler, it could also log position or whatever signal is selected.


> About position_logger.cc and my bad memory  if I use xemc as nmlfile
> obtain these error:
> 
> bkt@bkt:~/linuxcnc-dev$ '/home/bkt/linuxcnc-dev/lib/logger' xemc
> libnml/cms/cms_cfg.cc 623: cms_config: can't open 'xemc'. Error = 2 -- No
> such file or directory
> libnml/nml/nml.cc 370: NML: cms_config returned -1.
> 
> **
> * Current Directory = /home/bkt/linuxcnc-dev
> *
> **
> * BufferName = emcStatus
> * ProcessName = xemc
> * Config File = xemc
> * error_type = 0 (NML_NO_ERROR)
> 
> 
> obviously a linuxcnc Axis gui is open in my desk 
> 
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Re: [Emc-users] D. Garret's Dry Run LinuxCNC

[N]

> пт, 13 груд. 2019 о 18:38 Dewey Garrett пише:
> 
> > Current Docs:
> >
> >
> > http://buildbot.linuxcnc.org/doc/scratch/v2.9.0~pre0~dgarr-dryrun~6eca6ac/html/integrator/dryrun.html
> >
> >
> > http://buildbot.linuxcnc.org/doc/scratch/v2.9.0~pre0~dgarr-dryrun~6eca6ac/html/man/man9/dryrun_helper.9.html
> >
> > Branch ref: https://github.com/LinuxCNC/linuxcnc/commits/dgarr/dryrun
> >
> > This branch is force-pushed when there are changes.
> >
> 
> Thanks for the great job!
> 
> Is there a way to speed it up to estimate the program run time? I.e.
> simulation mode.

Have done similar for other programs. It was implemented as function called 
periodically and for simulation simply run in loop as fast as computer 
calculated. Assuming parameters for motion planner is correct so that there is 
no following error there should be no need to run feedback loop, trajectory 
planner should be enough.


I came to the conclusion program could either stop waiting for something like a 
periodic timer or be called then something happen for example triggered from a 
periodic timer. Stop waiting need support from operating system so that other 
threads could continue executing! Called then something happen and program must 
be implemented as a state machine!

It is often more work to implement as a state machine though control loops 
usually have very few states and i have an advantage it also could be called 
from interrupt which is particularly useful then timers with nested interrupts 
with priority could be used to call function.


Regards Nicklas Karlsson


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Re: [Emc-users] (no subject) Position logger, sampler?

[N]

Position logger is inteded for what?


> position logger is on test folder  but the problem was absolute path of
> linuxcnc.nml file . position_logger.cc when compile and launch need
> arguments  linuxcnc.nml file is the preferred one but absolute path is
> needed in any case (in my case i work inside linuxcnc-dev folder).
> 
> regards
> bkt
> 
> Il giorno sab 14 dic 2019 alle ore 11:33 N 
> ha scritto:
> 
> > Not sure what position_logger.cc is and do not find the file then
> > searching but myself used sampler, it could also log position or whatever
> > signal is selected.
> >
> >
> > > About position_logger.cc and my bad memory  if I use xemc as nmlfile
> > > obtain these error:
> > >
> > > bkt@bkt:~/linuxcnc-dev$ '/home/bkt/linuxcnc-dev/lib/logger' xemc
> > > libnml/cms/cms_cfg.cc 623: cms_config: can't open 'xemc'. Error = 2 -- No
> > > such file or directory
> > > libnml/nml/nml.cc 370: NML: cms_config returned -1.
> > >
> > > **
> > > * Current Directory = /home/bkt/linuxcnc-dev
> > > *
> > > **
> > > * BufferName = emcStatus
> > > * ProcessName = xemc
> > > * Config File = xemc
> > > * error_type = 0 (NML_NO_ERROR)
> > > 
> > >
> > > obviously a linuxcnc Axis gui is open in my desk 
> > >
> > > ___
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> >
> >
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> 
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Re: [Emc-users] (no subject) Position logger, sampler?

[N]

> ...
> Refer to our testsuite for a simple standalone "UI" program which is
> tested to correctly link in every build of LinuxCNC.
> 
> https://github.com/LinuxCNC/linuxcnc/blob/master/tests/build/ui/nml-position-logger.cc
> 
> For my side is a nice pieces of code that help me to understand the way to
> exchange nml signal from my c++ gui app to linuxcnc whitout using python.
> 
> regards
> bkt

That's different then I understand.


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Re: [Emc-users] linuxcnc versions, repository URL

[N]

> when I installed the 2.7.14 version,  it wants to connect to a repo that 
> doesn't exist.

My HEAD got totally detached but remember I had to switch repository url before 
that happened a while ago.


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Re: [Emc-users] Latency Warning Messages

[N]

> I bought 3 different low profile video cards to try and get rid of that 
> latency message.  The ultimate and best solution was to buy the MESA 7i92H.  
> Does away with the parallel port completely.
> John Dammeyer

The parrallel port cause latency messages?


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Re: [Emc-users] Next probably silly Q

[N]

The PWM tachometer signal most probably have really good noise immunity as 
timing is robust against noise. Might also have really good accuracy if derived 
from a clock with low jitter and slow enough clock drift. However very unlikely 
to make any noticeable difference on a fan.

Once asked for external availability of PWM signal on measurement instrument as 
I could see it was used internally in datasheet/manual for data transmission 
over an isolation barrier and they might have listened as I have seen it is 
available in some now though I did not yet have any use of it, have used the 
analog signal with more or less noise.



> With a 3-wire fan there are two power wires and the third is a tachometer.
>Fan speed is controlled by  varying the volts (or duty cycle) on the
> power wires.
> 
> With a 4-wire fan all thee above wires do the same thing but wire #4 is a
> speed control signal that is PWM.This saves the need to PWM the power.
> 
> On Tue, Dec 10, 2019 at 4:16 AM Gene Heskett  wrote:
> 
> > Greetings all;
> >
> > I am running the stretch iso install here on this big house box, but
> > since the fire destroyed the old Asus board, I now have a new Prime
> > Z370-A ll, with a 9nth gen 6 core i5 running at 3.7GHz and 32G of ddr4
> > memory.  Much quicker than the old 2.1GHz 4 core phenom. Pretty quick
> > now.
> >
> > But the cpu fan I put in, a monster cooler-master, has the new 4 wire
> > control, and is working very well, but is not reporting its speed.
> > A run of sensors-detect only found coretemp and once modprobed, thats
> > working well. Showing the max temps in the 29C range.  Its a BIG cooler
> > and I can't feel any heat at its base, so big I can't put the towers
> > side panel on as it (the coolers heat pipes and radiator) is about 1/2"
> > too tall.  Shrug, its been off for 12 years now ;-)
> >
> > Does anyone else have any experience with these newer 4 wire fans?
> >
> > Thanks  all.
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law respectable.
> >  - Louis D. Brandeis
> > Genes Web page 
> >
> >
> > ___
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> 
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[Emc-users] pcb-rnd, save .pcb file as lihata fail to load lihata, library pile up, plated slot will try manufacture

[N]

I discovered starting with a .pcb file and saving it as a lihata file then 
loading it did not work. During loading of lihata file originally saved from 
there was a few long lasting dialogs with among them "clip polygon" or 
something similar and eventually after quite many secondes I gave up. Tried 
several times until I come up with the idea select all, copy to paste buffer, 
start new design and paste into new design then saving/loading works. Not a 
problem and may even be a good idea anyway but to remember put on same grid as 
before by snapping to a point on an "even" grid even though this remember did 
not hapen first time make things easier.

It seems library paths are piling up in some way then loading lihata file but 
maybe it does not matter to much.

Now I could get lihata sub circuit file into pcb layout by using import gschem 
schematics, did not think about this before since used gsch2pcb because of 
missing library path. Eventually most probably within a week or two since I 
already spent the night club budget for this month on a good looking woman and 
have nothing else to do I will order a board with plated slot since it's useful 
on one of my boards.


Would guess this is known before.


Regards Nicklas Karlsson


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Re: [Emc-users] ESTOP and Machine Enable.

[N]

On Sun, 27 Oct 2019 12:43:04 -0700
"John Dammeyer"  wrote:

> What exactly is the difference in LinuxCNC with the red ESTOP button and the 
> orange Machine ENABLE button?

Pressing the button several times do not result in accidentaly turning it on 
again. If you are in hurry then you press the red ESTOP button which is not to 
unlikely to happen then eventually pressed this might be good I guess.


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Re: [Emc-users] ESTOP Power Control --> relativel safe keep alive

[N]

On Wed, 23 Oct 2019 17:16:39 -0700
"John Dammeyer"  wrote:

> I've added back the safety aspect of an ESTOP event shutting down all high 
> voltages.  The low voltage 24V stays on as does the PC/Monitor and the AC to 
> the PMDX-126 BoB.  Ie. I have two 220VAC circuits.  One for all the Motor 
> power and one for the Control power.  Only the Motor Power is removed.
>  
> Now click on the little orange icon to re-enable the system, ENABLE goes 
> active and the AC Motor Power Relay switches  ON.
>  
> Interlocks prevent this while:
> 1.  An ESTOP is still pressed
> 2.  Spindle Motor Switch is in ON position, 
> 3.  Limit Switches are not in override if they were the cause of the 
> ESTOP in the first place and are still activated.
>  
> The ENABLE from the PC goes through the BoB and out to the various drives.  
> This happens faster than the high voltage power supplies for the drives.  
>  
> Is there a way to delay the ENABLE out?

You put a delay block on ENABLE out enable flank?

> Or will I be forced to build a circuit that makes sure the high voltages are 
> within range and use the output of that to gate the ENABLE?

With a DC servo cutting gate driver voltage is not enough in case transistors 
fail in opposite directions, guess it's not unlikely to happen if servo is 
overloaded with a resulting over current in transistors.

> What's everyone else doing?

For the emergency stop I would buy a real emergency button and connect so that 
power is cut to make machine stop. Then pressed it should also be sensed so 
that emergency stop in Linuxcnc is toggled. I would not trust emergency button 
in Linuxcnc, the computer may stop responding for many reasons. An extra switch 
maybe with personal padlock might also be good then working with the machine, 
Injection mold machines at least sometimes also have a mechanical lock.

Programming errors or other logical errors are common. Safety circuit should be 
simple to check and understand though there might also be a cases there a 
complex sequence which must work to keep alive is suitable, I would guess to 
succesfully reading a bar code or QR code to keep alive could be made so that 
likelyhood for an error in wrong direction is very low.

Put a toggle signal in Linuxcnc, send it out on all motor driver outputs to a 
transformer connected to a safety relay which is connected in series so that 
power is cut if signal is not regularly toggled would probably add some safety 
but in case encoder signal is lost a servo drive is likely to move to one of 
the end stops.


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Re: [Emc-users] ESTOP Power Control --> relativel safe keep alive

[N]

> ...
> > > What's everyone else doing?
> > 
> > For the emergency stop I would buy a real emergency button and connect so
> > that power is cut to make machine stop. Then pressed it should also be
> > sensed so that emergency stop in Linuxcnc is toggled. I would not trust
> > emergency button in Linuxcnc, the computer may stop responding for many
> > reasons. An extra switch maybe with personal padlock might also be good
> > then working with the machine, Injection mold machines at least sometimes
> > also have a mechanical lock.
> 
> The ESTOP circuit is still set up the way it was in the original hardware.  
> The NC ESTOP switch routes control to the AC contactor relay.  There's a 
> second NC contact that is sensed by the BoB and the system.  The main 
> contactor control circuit runs through a second NC ESTOP switch and also 
> through a relay controlled by the BoB and therefore from the LinuxCNC Enable 
> button.
> 
> So either an operator generated ESTOP or a LinuxCNC generated ESTOP will open 
> the circuit to the main AC contactor.  As will a broken wire in that chain.

This seems good.

> > Programming errors or other logical errors are common. Safety circuit should
> > be simple to check and understand though there might also be a cases there a
> > complex sequence which must work to keep alive is suitable, I would guess to
> > succesfully reading a bar code or QR code to keep alive could be made so 
> > that
> > likelyhood for an error in wrong direction is very low.
> > 
> > Put a toggle signal in Linuxcnc, send it out on all motor driver outputs to 
> > a
> > transformer connected to a safety relay which is connected in series so that
> > power is cut if signal is not regularly toggled would probably add some 
> > safety
> > but in case encoder signal is lost a servo drive is likely to move to one 
> > of the
> > end stops.
> > 
> 
> My softstart is controlled by a small 8 pin PIC.  This s the same processor 
> that also does the over voltage clamping and automatic fast drain of the 
> power supply on loss of AC power.  I can use that softstart signal to gate 
> the enable to the STMBL drive.

Even though it's unlikely it could fail. Commercial drives use to have a safe 
torque off input. I expect it work for AC motors but if a DC motor is 
overloaded semiconductors usually fail with short so it could run at full speed 
in one direction even if control signals are turned off.

Most of the time I expect no one is in the danger zone but if it is likely 
someone is in the danger zone then emergency is activated it is important it 
could be trusted. Misstakes happens but otherwise there is a reason to press 
the emergency stop.


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Re: [Emc-users] ESTOP Power Control --> relativel safe keep alive

[N]

> > Even though it's unlikely it could fail. Commercial drives use to have a 
> > safe
> > torque off input. I expect it work for AC motors but if a DC motor is
> > overloaded semiconductors usually fail with short so it could run at full 
> > speed
> > in one direction even if control signals are turned off.
> 
> 
> The HP_UHU DC Servo drives track the encoder verses input pulses.  So if the 
> motor goes off and exceeds the tracking error a fault is generated.  The 
> board has a coupled FAULT_OUT/IN circuit so that when one motor faults it 
> pulls down the fault line (Open Collector).  Since the other drives are also 
> connected to this same signal a fault from one drive takes the whole works 
> down.

Maybe except for a failed sensor. Semiconductors usually fail short circuited 
so properly designed it could probably be made safe with high integrety. To be 
really sure position sensor must "continuously" which in practice might be 
periodically often enough read a known sensor value, it is important failure of 
sensor does not produce known sensor value, not necessarily with accuray good 
enough for normal use, accuracy good enough to keep it from move far enough 
away to get unsafe should be good enough.

If this is not fulfilled I would not consider machine really safe from 
uninteded movement unless E-stop is pressed. Even if risc of failure is small 
it add up if you work within reach of machine year after year. I have seen fork 
lifts with automatic leveling, if this is not properly done so that it move to 
the end in case a sensor fail I would not be suprised if it would happen to a 
few after some years if many enough is manufactured.


Logical errors are common so I might have made some misstake above.


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Re: [Emc-users] Gnome v Patent Troll --> payment method

[N]

Prefer bank account because then I tell bank there money should be transferred 
and no one else. Then of course there must some kind of secure mechanism to 
communicate. For large amount of money I prefer an account there I have enter 
bank in person and bank is responsible for identification, this is because then 
robbers must go to bank. For transfers over Internet for example using the new 
modern telephones this could be used for robbery, there is among other problems 
a problem to get away with the money but chose the right person and there are 
plenty of money and worth to spend quite much effort on planning.

In my country cards there payment terminal is supplied by seller is most often 
used. This system assume receiver of money i honest and I guess it's rather 
simple to modify terminal to show wrong amount. There is however still the 
problem to get away with the money before anyone discover. It works in a well 
policed but otherwise I would expect problems. Not especially worried but it 
sometimes keep me from using them then company could be expected to have bad 
economy, I also quite often avoid them because I do not want to tell bank where 
my money is spent.



> Gene,
> 
> Even if you did want to use the bank account method rather then PayPal
> you would not give the Gnome people your account number.  They are
> using "Plaid".   They are an actual on-line banking platform.
> 
> In any case, every time you write a paper check or use your credit
> card you are giving someone the account number.These services like
> Plaid and PayPal or Apple Pay stop that from happening.   They also
> provide fraud protection in case you were scammed.  They can reverse
> transactions even a few months later.
> 
> On Mon, Nov 25, 2019 at 4:52 AM Gene Heskett  wrote:
> >
> > On Monday 25 November 2019 07:15:58 andy pugh wrote:
> >
> > > Gnome are being sued by a patent troll:
> > > https://insight.rpxcorp.com/litigation_documents/13472237
> > >
> > This is so poorly translated into a pdf that its without any readable
> > content. Only the first line of any content made it into the pdf.
> >
> > > Gnome are trying to raise funds to fight this:
> > > https://www.gnome.org/news/2019/10/gnome-files-defense-against-patent-
> > >troll/
> > >
> > I had a donation ready to go, but what do I use for credentials? No
> > opportunity to use a credit card. And obviously passwords and routing
> > numbers are not going to be used for my own security. And who the hell
> > is this "middle man"?  I backed out obviously and despite the middle
> > mans threats.  I may be country boy dumb, but I'm not stupid.  This
> > looks like a phishing scam to me.
> >
> > > Even if you are not using the GNOME desktop, if you are using LinuxCNC
> > > you are using Gnome software. (GTK, for one)
> >
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law respectable.
> >  - Louis D. Brandeis
> > Genes Web page 
> >
> >
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> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> 
> 
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Re: [Emc-users] (Off topic) A Question Re: BOBs and Opto-Isolators

[N]

> Hello All -- especially Gene,
> 
> I've seen many posts on the lists regarding breakout boards and dealing
> with issues regarding slow opto-isolators. I have a question:
> 
> Is anyone using: ISO776x 
>  devices?

Well, not exactly his one but there are others with different numbers of 
isolation barriers/directions and these I have used. I think they are really 
good.

> They are 100 MHz data rate devices, have high isolation, have six in a
> package, and look like they would work just fine. The only downside might
> be that they are limited to 5.5 volts on the output, so you might need to
> add a transistor driver after them.

It is common Micro controllers have at least some 5 volt tolerant inputs. I 
have seen one of the new Micro controllers have 5 volt externally which 
probably is a rather good idea even if internal logic run on lower voltage.

> ... And all of the ones in a single package
> share a ground.

It's a drawback but only if you have separate supply voltage for each channel 
otherwise they are connected anyway.


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Re: [Emc-users] Fotek SSR

[N]

> I have a bunch of Fotek SSRs, rated 385V / 40A.
> 
> Well, that's what it says on the label.
> 
> Perhaps I have been hanging around with Americans too long, but I
> recently bought a bullet-casting melter. I wasn't happy with the
> temperature controller, so I modified it with a PID controller and
> SSR.
> 
> https://photos.app.goo.gl/mq4NFtVtiSsVHFSk9

There is lead in the bucket?

> (A variant of that 1/32 DIN controller has a built-in 5A SSR, which
> might be an easier modification, but I used the relay / ssr driver
> version: https://www.ebay.co.uk/itm/193179699038 )
> 
> I measured the cold resistance of the element at 111ohms, so that's
> nominally 2A, or 3A if we allow for the actual peak mains voltage.
> 
> So I figured that the 40A SSR should be fine. Imagine my surprise when
> it failed short-circuit almost immediately.

You know what effect lead have on cognitive performance?

> It was potted up, and when I pulled it apart the actual driver chip
> fell apart, so no way to be sure what the actual rated current was
> now. The last one of these I took apart had a 10A driver, so that is
> what I have been mentally rating them at. Perhaps I was wrong.
> Possibly it's a fake 10A driver in a fake 40A SSR?

With 230Vac or so and 111ohms DC resistance should be slightly above 2Arms, 
less than 3A peak, then inductance may lower current further a lot of margin. 
Thyristor/Triac may fail to turn off if there is to much inductive load unless 
a snubber capacitor is added to limit dv/dt and think it is common to use these 
in SSR.

> If you are wondering why a resident of the UK wants a bullet mould, I
> have been making tiny glass-bottomed peter tankards:
> https://photos.app.goo.gl/RHmiUKG1BtCT5qW16

Sure.

> -- 
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1912
> 
> 
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Re: [Emc-users] Homann Designs ModIO, OT but related to topic

[N]

A dead mans grip would had been good. This is one of the few cases there I 
would trust software as an active signal passing a rather complex chain 
sequence is needed to get things moving, this have less to do with the software 
and more with the hardware since it's impossible to check if it might brake and 
what happen.

> A movie was made based on this one, but of course it had to change a bunch of 
> stuff when sticking to the real details would have been plenty dramatic.
> 
> https://en.wikipedia.org/wiki/CSX__incident 
> 
> On Saturday, February 8, 2020, 6:30:36 AM MST, N 
>  wrote:  
>  > On 02/07/2020 11:43 AM, N wrote:
> > > Are however not sure the westinghouse system is better 
> > > there pressure is loaded then breaks are not used. First 
> > > time I heard about the accident there an oil train have 
> > > crashed then driver was sleeping and left engine on 
> > > locomotive running I thought driver was drunk. Later 
> > > however I learned fire department put out fire and did not 
> > > know it should be running to keep pressure up, this system 
> > > is still allowed? Or I got it wrong?
> > Yes, the catastrophe was in Canada where a freight train 
> > loaded with oil tank cars was parked on a weekend, the 
> > locomotive engines were left running so the parking brake 
> > would continue to hold.  There was no crew on the train.  
> > One of the locomotives caught fire, the fire crew was called 
> > and put it out, and they shut off both locomotive engines.  
> > About 8 hours later the air tanks leaked down, and the train 
> > rolled downhill and crashed on a curve, essentially burning 
> > an entire small town to the ground.
> > 
> > As far as I know, the air brake system on trains has not 
> > been changed very much in the last hundred years, it was 
> > used on steam locomotives before Diesels.
> 
> Have seen example on youtube there a canadian train break in two there breaks 
> are automatically applied on the last wagons so they stop. Have also seen 
> some movies/examples of runaway train from USA but do not think this is a big 
> problem in other countries. Tried to find information on train brakes in 
> Sweden, compressed air is used to release break, think a spring is used to 
> apply brake but failed to find information. I however know there is some kind 
> of system to realese brakes so they could roll on there own then split and 
> building new trains, it is common a small hill is used for this to get wagons 
> slowly rolling, there is a switch so they could not get out onto ordinary 
> track in this case, maybe some other limitation.  
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Re: [Emc-users] Open source CNC architecture

[N]

> > You care where the loop are because if they are in your PC you need a
> > special PC with a special OS.
> 
> Special PC? Pretty much any PC will work. I guess you could call the OS 
> special but not nearly as special as an RTOS on an external processor. 
> If you are really that terrified of Linux, run LCNC headless and write a 
> Windows or web app to talk to it. The LCNC PC then becomes your external 
> CPU box.

Guess a raspberry will work fine, also small enough to put on a din rail or 
similar. It must be a device cheap and readily available, I know some of 
devices similar as this used on raspberry have time triggered send of Ethernet 
messages which is nice but more than needed for a few axis but are not certain 
about this used in Raspberry.

Used PLC with similar or same chip and it does not have any kind of local user 
interface instead I use Ethernet and ordinary to computer to communicate with 
it. Could follow what happen in real time and receive data sent periodically 
over Ethernet but could not be really certain which messages get priority if 
there is more traffic. Often use Youtube, it is more bandwidth but slower 
update rate and certain there is a receive buffer, most of the time but not 
always perfect then used for other things, it will however not make 
dents/scratchs in the monitor so is not very important.


Regards Nicklas Karlsson


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Re: [Emc-users] Open source CNC architecture --> mesa motion controller

[N]

> If " 'nix" were suddenly removed from the world the internet and a whole 
> bunch of other thing would disappear.
> 
> Just to rock the boat: mesa (PCW) has a very nice motion controller for 
> an FPGA. 50 us cycle time, etc. "ALL" someone has to do is wrap  interp 
> and all the other non-motion stuff around it. Of course it is single 
> source, etc.

It is possible to run the motion controller on mesa FPGA?


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Re: [Emc-users] about NML - RCS_CMD_CHANNEL/EMC_CMD_MSG - EMC_AUX_ESTOP_ON

[N]

If you figure out what code do and comment is missing you could add it. Or you 
made agreement not to comment his code?

> Not sure I understand what you meant here.
> 
> > -Original Message-
> > From: N [mailto:nicklas.karlsso...@gmail.com]
> > Sent: February-23-20 1:12 AM
> > To: Enhanced Machine Controller (EMC)
> > Subject: Re: [Emc-users] about NML - RCS_CMD_CHANNEL/EMC_CMD_MSG
> > - EMC_AUX_ESTOP_ON
> > 
> > > @ John Dammeyer
> > >
> > > I'm quite sure that labview project at least work great  the difficult
> > > is study lcnc code (write in a good way but not rich of comment ... on the
> > > other hand, I agree not to comment too much on his code)
> > 
> > Something adding some comments to code then you read it?
> > 
> > 
> > ___
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
> 
> 
> 
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Re: [Emc-users] Servo thread, message queque any problem?

[N]

> > . Do anybody no if there might be any problems sending messages to a 
> > message queue from a Linuxcnc servo thread? Or a Linux real time task?
> 
> It is common for LinuxCNC user-space processes to connect to real-time tasks. 
> I know this happens in HAL ( halui is user-space as an example).  
> Some form of handshake might be needed to confirm data receipt and freshness. 
> 
> http://linuxcnc.org/docs/2.8/html/code/code-notes.html
> 
> Shows NML messaging as outside real-time, but communicating with it. 

This made me think again and NML must most certainly be a better choice since 
this used for everything else.


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Re: [Emc-users] Open source CNC architecture

[N]

On Tue, 28 Jan 2020 22:27:01 -0800
Chris Albertson  wrote:

> On Mon, Jan 27, 2020 at 11:06 AM Gene Heskett  wrote:
> 
> > On Monday 27 January 2020 11:39:27 dave engvall wrote:
> >
> > > Linuxcnc get used because it works ... at least well enough to get
> > > most jobs done.
> >
> 
> The topic came up because someone asked if anyone was using LinuxCNC for
> large scale work.   No one raised their hand.   Why are they not using
> LinuxCNC to make transmission parts at the Toyota factory?  It seems to be
> powering a few one-man shops and some hobby projects.

Are in doubt is a good idea to make parts for large company. Don't know but 
expect they are very likely to make complaint and claim high damages. Not sure 
if got last sentence correct. What I would expect then making part for a large 
company is a lot of work and little money at best.

It might be you need is machine from one of large companies, or at least 
measurement machine from one of the large companies to fight there claims.

> Why?  Someone might think that open source is not usable in industrial
> settings but.  That is clearly not true.   It must be something about
> LinuxCNC that makes it unsuitable.   I'm guessing itis the platform and
> that it does not work well out of the box and is basically just a kt of
> parts and not a product and it does not scale well to large factory floor
> sized systems.

Expensive companies usually claim a well known brand is better.

> But it does work well-enough for small shops where the owner is willing to
> invest much of his own time.

Might be a good point, if there is not enough money in case something does not 
work as expected investing some more time might be a possibility for a small 
one man workshop. Then salary is not everything, your own workshop nearby then 
no time need to be spent on traveling nor money, it might also happen workshop 
is located on country side there living is cheap and usually it's rather boring 
to work in a factory.


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Re: [Emc-users] Real-time OS for machine controllers (do not worry to much)

[N]

>  would not worry too much about who's RTOS you use.   The concepts are
> universal.  First you come up with a high-level design and work out the
> interfaces then you need to decide how wide of a range of hardware you need
> to support.  Then do some prototyping.   You will very quickly have your
> list down to a small handful.
> 
> People always get hung up on tools.That is not what matters.  What
> matters is the high level system architecture and how you design the
> interfaces between the parts.

Agree, what calculator is used does not matter if you do not understand the 
mathematics book in whatever form you happen to read it nowadays.


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Re: [Emc-users] Open source CNC architecture

[N]

> > ...
> 
> The mindset at the larger companies is not one of the 'time is money'
> rather than a cya attitude. The manager of the larger company answers to an
> entity above. The entity above doesn't make the decision to install
> LinuxCNC or not. The manager of the company makes the decision. The manager
> will decide based upon whether the decision is justifiable to keep his job.

Heard that no one got fired for buying an IBM. Also remember an old IBM 
computer on my workplace and a middle aged man mysteriously quitting.


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Re: [Emc-users] Real-time OS for machine controllers --> Micrium open source

[N]

Have been looking at Micrium suspect they might be really good.

Tried µC-probe, a really good idea and a really good software to have for real 
time applications but at least the GUI must have been written by a "modern" 
programmer with all newly invented programming paradigms or whatever it is 
called, looked very nice but slow like syrup and did not work well.


> Here's a copy of an email I received about the Open-Source Licensing Now 
> Available for Micrium µC/ RTOS
> I haven't used this one but maybe they were losing ground to the Free RTOS?
> 
> John
> 
> 
> =
> During the following weeks, Silicon Labs will transition the µC/ components 
> to an open-source license model.  
> By adopting permissive license terms for the µC/ components, we will make the 
> benefits of this software available to the widest user base possible and give 
> the embedded community a role in future development efforts.  
> Please note: This licensing change does not affect our exclusive Micrium OS 
> software available to developers through Simplicity Studio. Although it’s not 
> open source, Micrium OS can be used commercially on Silicon Labs’ EFR32 
> wireless SoCs and EFM32 microcontrollers (MCUs) with no licensing fees. 
> We want to ensure a smooth transition to open-source terms for all licensees 
> of the µC/ software. We will continue to provide technical support for 
> customers with valid maintenance agreements. We are also working closely with 
> partners who may offer similar support agreements in the near future.   
> The new open-source license model will go into effect on February 28, 2020. 
> Customers currently considering a license or maintenance renewal for any of 
> the µC/ software components (µC/OS-II, µC/OS-III, µC/FS, µC/TCP-IP, 
> µC/USB-Device, µC/USB-Host, µC/CAN, and µC/Modbus) have two options: 
> 1.Submit a PO for the µC/ part numbers until February 7. Any purchases 
> made during this period will include technical support through the end of 
> 2020.   
> 2.Once the new licensing terms for the µC/ components are in place, you 
> may obtain the software at no cost for commercial use (without technical 
> support from Silicon Labs)
> ==
> 
> 
> > -Original Message-
> > From: N [mailto:nicklas.karlsso...@gmail.com]
> > Sent: January-28-20 11:55 AM
> > To: Enhanced Machine Controller (EMC)
> > Subject: Re: [Emc-users] Real-time OS for machine controllers
> > 
> > rtems could without doubt be worth a try but have only used FreeRTOS and
> > it work.
> > 
> > FreerRTOS usually run scheduler at 1kHz and using one of the newer Micro
> > controllers like Cortex-Mx which is a very common CPU in these with
> > prioritized interrupts for higher priorities work really well. There is also
> > support calling some of the functions from within interrupts but not all 
> > since
> > they are not allowed to block.
> > 
> > It might be this prioritized interrupt controller may make FreeRTOS work
> > really well since then interrupts could be assigned a priority so that they 
> > are
> > correctly scheduled and guess this is not the case on an ordinary computer.
> > 
> > 
> > Guess NML would be a better choice for remote display.
> > 
> > 
> > > FreeRTOS sure is popular.  Have you compared it to other open source
> > > Posix standard real-time OS's such as NuttX and RTEMS?
> > >
> > > http://www.nuttx.org/
> > >
> > > http://rtems.com/
> > >
> > > Any thoughts? I haven't worked with any real-time OS's much since the
> > > 80-90's.
> > >
> > >
> > > On 1/21/20 2:22 PM, Chris Albertson wrote:
> > > > Doing a fresh start in 2020, I'd pick a 32-bit microcontroller platform 
> > > > and
> > > > then a "hard" real-time OS that is portable over a wide rand of 32-bit
> > > > microcontrollers.   FreeRTOS would be a example of this.  See
> > > > https://en.wikipedia.org/wiki/FreeRTOS
> > > > These OSes are nothing at all like Linux.  They have no user interface 
> > > > and
> > > > are linked with the application.


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Re: [Emc-users] Open source CNC architecture --> RTOSes

[N]

On Tue, 4 Feb 2020 11:21:25 -0800
Chris Albertson  wrote:

> If LinuxCNC where to be ported, the best platform likely would not use an
> OS like Linus or BSD or Windows.The RTOSes all are very different from
> the more general-purpose OSes. Linux.BSD/Windows all have kernels and
> can load and run binary images that are loaded from disk-like storage and
> have some kind of user interface.  An industrial ROTS does not do
> that.  It is literally 1000X  simpler and just runs one thing when you
> apply power.Think of how a color laser printer works. There is likey an
> RTOS inside.

FreeRTOS and similar do not run Linux applications and they do not have a full 
implementation of POSIX. Usually they run only code from the builtin Flash 
memory and this is then I use them if an operating system at al.

> A laser printer is a good example of how people really want a CNC mill to
> work.  You design you document on the computer then press "print" and the
> printer creates it.   After the last of the data is moved to the printer
> you can turn the PC off it you like.

Might be a good idea to put the real time part, maybe also g-code interprter on 
one these simpler operating systems and have user interface on ordinary 
computer, not exactly as a laser printer but something towards that direction. 
Think some PLCs have a g-code interpreter and quite many are simple devices 
without a graphical user interface device put on a DIN rail, possibility to add 
user interface or chose with builtin is also possible.


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Re: [Emc-users] Probing a Profile --> Coordinate measurement machine

[N]

Anyone used a coordinate measurement machine and know how they do?

Maybe I happen to have manual but will probably not have to much time to look 
into it this week.

> I think it comes down to constructing lines perp to the profile at 
> probed points. CMM's obviously take care of this somehow.
> 
> I've done it the hard way by drawing circles the diameter of the probe 
> and then doing three pt arcs to fit. Certainly there are better and 
> considerably more elegant ways to do this. What I can visualize in 
> concept I cannot convert to good calculations. ;-)  I passed calculus 
> but knew better than to try dif-e-q. A second order curve fit tangent to 
> multiple circles might be a better approach.
> 
> "Implementation is left as an exercise for the student."  :-)
> 
> Dave
> 
> On 2/4/20 3:57 AM, andy pugh wrote:
> > Does anyone have a G-code routine to probe around a profile to trace it out?
> >
> > I imagine some sort of "keep turning right" algorithm should be able
> > to walk round a profile, though exactly how you compensate for probe
> > diameter on external corners has me a bit stumped.


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Re: [Emc-users] Homann Designs ModIO --> A little bit OT

[N]

If I got it correct a sales person said there new modern drives could be 
equipped with a cheap modbus module so it might still be useful even though it 
is an protocol.

> The wiki for this is out of date.  
> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?ModIO
> 
> First of course the folder linkages should now read linuxcnc rather than EMC2.
> 
> Also the document states:
> 
> Both Driver Directories Need
> modbus.c 
> modbus.h 
> findbindir 
> find-libdir 
> find-modinc
> 
> But the linked folders to download these are either broken or wrong.
> 
> The driver code homann_modio.c is also missing LCD support so that needs to 
> be finished.
> 
> Since I have a ModIO, an MPG Encoder wheel and a cheap 4x20 line display 
> somewhere on route from China I'd like to take a stab at making it work on 
> LinuxCNC. 
> 
> Clearly the make files also need to be edited to fix path and filenames like:
> emc/usr_intf/axis emc/usr_intf/touchy emc/usr_intf/stepconf 
> emc/usr_intf/pncconf \
> 
> Or has this all been done already by someone?
> 
> Thanks
> John


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Re: [Emc-users] Homann Designs ModIO

[N]

Could see mb2hal files in my directory so I guess they are normally compiled.

If I got it correct a sales person said there new modern drives could be 
equipped with a cheap Modbus module so it might still be useful even though it 
is an protocol.

> The MB2HAL module should be able to talk to it 
> . I/O should be no 
> problem but the display may be a bit awkward.
> 
> Les
> 
> On 06/02/2020 07:43, John Dammeyer wrote:
> > The wiki for this is out of date.  
> > http://wiki.linuxcnc.org/cgi-bin/wiki.pl?ModIO
> >
> > First of course the folder linkages should now read linuxcnc rather than 
> > EMC2.
> >
> > Also the document states:
> >
> > Both Driver Directories Need
> >  modbus.c
> >  modbus.h
> >  findbindir
> >  find-libdir
> >  find-modinc
> >
> > But the linked folders to download these are either broken or wrong.
> >
> > The driver code homann_modio.c is also missing LCD support so that needs to 
> > be finished.
> >
> > Since I have a ModIO, an MPG Encoder wheel and a cheap 4x20 line display 
> > somewhere on route from China I'd like to take a stab at making it work on 
> > LinuxCNC.
> >
> > Clearly the make files also need to be edited to fix path and filenames 
> > like:
> >  emc/usr_intf/axis emc/usr_intf/touchy emc/usr_intf/stepconf 
> > emc/usr_intf/pncconf \
> >
> > Or has this all been done already by someone?
> >
> > Thanks
> > John
> >
> >
> >
> >
> > ___
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
> 
> 
> 
> 
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Re: [Emc-users] Linuxcnc 2.9.0 hangs

[N]

In synaptic, the dialog about where to get packages on the tab updates, there 
is text "buster/updates" and "buster-updates" so I guess it must be buster. 
/proc/version claim it is (Debian 8.3.0-6)


> On 2020-02-02 22:06, N wrote:
> 
> > Pretty sure I use buster on several machines.
> > 
> 
> You use linuxcnc with buster?
> 
> Tom Dean
> 
> 
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Re: [Emc-users] Homann Designs ModIO --> reltime serial but Ethercat worse

[N]

> > With how cheap realtime i/o is - I don't see the a lure of modbus.
> 
> Modbus non-realtime should be plenty fast enough for spindle control 
> unless you are doing position control of the spindle. I'm not sure about 
> RTAI but if you are using preempt-rt mb2hal should be pretty close to 
> real time.

Think preempt-rt is good enough for ordinary UART but expect exception for 
example if connected via USB.

However think Ethernet is not perfect, maybe only small delay minutes or so in 
between but still not perfect. Have done hal delay test and it's fine. If I 
remember correct there are however some delay then using Ethernet minutes in 
between or so, this might be because other Linux processes related to network 
is running so something else sent sometimes, did not yet have time to check 
this carefully. In doubt delay is long enough to have any effect on part 
quality.


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Re: [Emc-users] Homann Designs ModIO, OT but related to topic

[N]

> My 2 cents.  For some things non-realtime i/o is fine.  I have seen too
> many times where someone is maybe controlling a spindle and wonders why a
> change in direction takes so long and or isn't consistent.  Once they
> switch over to something realtime (+/-10v or pwm) the issue goes away.

Heard story about delays of brakes on trains then toilet started to get full 
there was a switch toggling but not sure if it was true, probably need a 
passive system there signal must arrive within some specified time or brakes 
are applied. Are however not sure the westinghouse system is better there 
pressure is loaded then breaks are not used. First time I heard about the 
accident there an oil train have crashed then driver was sleeping and left 
engine on locomotive running I thought driver was drunk. Later however I 
learned fire department put out fire and did not know it should be running to 
keep pressure up, this system is still allowed? Or I got it wrong?


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Re: [Emc-users] Homann Designs ModIO, OT but related to topic

[N]

> On 02/07/2020 11:43 AM, N wrote:
> > Are however not sure the westinghouse system is better 
> > there pressure is loaded then breaks are not used. First 
> > time I heard about the accident there an oil train have 
> > crashed then driver was sleeping and left engine on 
> > locomotive running I thought driver was drunk. Later 
> > however I learned fire department put out fire and did not 
> > know it should be running to keep pressure up, this system 
> > is still allowed? Or I got it wrong?
> Yes, the catastrophe was in Canada where a freight train 
> loaded with oil tank cars was parked on a weekend, the 
> locomotive engines were left running so the parking brake 
> would continue to hold.  There was no crew on the train.  
> One of the locomotives caught fire, the fire crew was called 
> and put it out, and they shut off both locomotive engines.  
> About 8 hours later the air tanks leaked down, and the train 
> rolled downhill and crashed on a curve, essentially burning 
> an entire small town to the ground.
> 
> As far as I know, the air brake system on trains has not 
> been changed very much in the last hundred years, it was 
> used on steam locomotives before Diesels.

Have seen example on youtube there a canadian train break in two there breaks 
are automatically applied on the last wagons so they stop. Have also seen some 
movies/examples of runaway train from USA but do not think this is a big 
problem in other countries. Tried to find information on train brakes in 
Sweden, compressed air is used to release break, think a spring is used to 
apply brake but failed to find information. I however know there is some kind 
of system to realese brakes so they could roll on there own then split and 
building new trains, it is common a small hill is used for this to get wagons 
slowly rolling, there is a switch so they could not get out onto ordinary track 
in this case, maybe some other limitation.



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Re: [Emc-users] Real-time OS for machine controllers

[N]

rtems could without doubt be worth a try but have only used FreeRTOS and it 
work.

FreerRTOS usually run scheduler at 1kHz and using one of the newer Micro 
controllers like Cortex-Mx which is a very common CPU in these with prioritized 
interrupts for higher priorities work really well. There is also support 
calling some of the functions from within interrupts but not all since they are 
not allowed to block.

It might be this prioritized interrupt controller may make FreeRTOS work really 
well since then interrupts could be assigned a priority so that they are 
correctly scheduled and guess this is not the case on an ordinary computer.


Guess NML would be a better choice for remote display.


> FreeRTOS sure is popular.  Have you compared it to other open source
> Posix standard real-time OS's such as NuttX and RTEMS?
> 
> http://www.nuttx.org/
> 
> http://rtems.com/
> 
> Any thoughts? I haven't worked with any real-time OS's much since the
> 80-90's.
> 
> 
> On 1/21/20 2:22 PM, Chris Albertson wrote:
> > Doing a fresh start in 2020, I'd pick a 32-bit microcontroller platform and
> > then a "hard" real-time OS that is portable over a wide rand of 32-bit
> > microcontrollers.   FreeRTOS would be a example of this.  See
> > https://en.wikipedia.org/wiki/FreeRTOS
> > These OSes are nothing at all like Linux.  They have no user interface and
> > are linked with the application.
> 
> 
> 
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Re: [Emc-users] Open source CNC architecture --> EMC, Electro Magnetic Compability

[N]

> ...
> The EMC(squared) corporation threatened to sue over anything 
> that used "EMC" in it,
> and so the name had to be changed.  LinuxCNC is totally the 
> continued development
> of EMC2, just under a different name.
> 
> Jon

Also avoid confusion with Electro Magnetic Compability (EMC) which happen to be 
a more or less common problem then using servo drives.


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Re: [Emc-users] Linuxcnc 2.9.0 hangs

[N]

> On 2020-02-01 20:46, Jon Elson wrote:
> > On 02/01/2020 08:35 PM, Thomas D. Dean wrote:
> >> I have been using linuxcnc 2.9.0~Pre0 from sources, run in place.  
> >> Until today, it has worked, mostly.  Before today, about 2x per week 
> >> it would freeze and I had to cycle power to get it working.  Now, 
> >> linuxcnc freezes.
> >>
> > Does it ONLY freeze when LinuxCNC is running?  But, just keep working if 
> > you DON'T start LinuxCNC?
> > In that case, the most likely problem is the BASE_THREAD has too short a 
> > period.  Try increasing
> > the BASE_THREAD period in the .ini file and see if that fixes it.
> > 
> 
> I changed the BASE_THREAD period by a factor of 10x then 100x, with the 
> same result.

Had similar problems and removed graphics card, used the builtin instead and it 
started to work.

Pretty sure I use buster on several machines.


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Re: [Emc-users] Open source CNC architecture - open source complexity OT, more off it

[N]

> Some colleges and universities offer many online courses for free or very low 
> cost. The online course materials are identical to what's used in the classes 
> at the schools, and lectures are either recorded from actual classes or are 
> the same material the professors present to a class. For some of them the 
> professors will answer questions e-mailed to them.

It is common course page are publically available on Internet with a list of 
litterature used. Lectures recorded from actual classes are probably a very 
good for economical reasons, it is one way communication anyway so money or 
time of professor could be better spent answering questions for example via 
E-mail. Classes are more useful as you could discuss with others, help each 
other and ask questions to the teacher provided teacher do not speak to much of 
the time.

> What you don't get is a diploma or a degree. For the free or low cost you get 
> a "Certificate of Completion". If you want a degree or diploma then that 
> costs more and there are specific sets of classes one has to take, but it's 
> still far less costly than attending the classes in person.

Have taken courses more less by studying for myself and attend the written 
exam. In my last exam they had been able to span the course very well in just a 
few questions, I passed but did not get good grade, this is partly because I 
had other priorities work full time, fix a few things at my home, spent quite 
much time on night clubs as I live alone.

A written exam you have to take in person, sometimes there is a given task you 
have to do in group and I guess this might be harder to check as some members 
could get away with very little effort spent on it.

>MIT was one of the first to do this, and still does. 
> https://ocw.mit.edu/index.htm

Think they had or have some kind of cooperation with University there I studied.


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Re: [Emc-users] [Emc-developers] Looking to make hex offset list for NML status shared memoryr

[N]

Think zeromq is used for message passing, found only a few functions. 
Interestingly enough in one of the example https://zeromq.org/languages/c/ they 
send using TCP/IP which is the same protocol NML use. I get the impression 
zeromz is message oriented while TCP/IP is an endless stream of data. 

Anyone looked into the code of Machinekit?

> If the machinekit fork was so good as far as making the information more 
> structured why did that fork not get adopted into the main stream?  Is it 
> just that for existing installations, that already work, the attitude is why 
> change?
> John
> 
> 
> 
> > -Original Message-
> > From: N [mailto:nicklas.karlsso...@gmail.com]
> > Sent: February-17-20 12:38 PM
> > To: Enhanced Machine Controller (EMC)
> > Subject: Re: [Emc-users] [Emc-developers] Looking to make hex offset list
> > for NML status shared memoryr
> > 
> > > On 17/02/2020 18:15, Johannes Fassotte wrote:
> > > > I'm reviewing currently available documentation from the NIST on how a
> > > > remote user is fed status information. From what I can tell based on
> > > > my experiments is that the raw data file is sent to the remote for
> > > > decoding and that the remote is able to do that without issues for the
> > > > entire status data set.
> > >
> > > Yes, that is correct.
> > >
> > > >
> > > > Thus Im thinking that the location of each item withing the data set
> > > > is stable for a particular configuration. If structure lengths are
> > > > changed or new ones are added via a update then NML has that
> > > > information available within itself and it should be able to be pulled
> > > > out for use by a remote user to allow proper decoding of the raw
> > > > status data it receives.
> > >
> > > The status messages don't contain any type or size information. They are
> > > just anonymous blobs of data. Both the source and the destination have
> > > to be using the same specification or bad things happen. This is one of
> > > the things the Machinekit project wanted to fix.
> > 
> > From the zeromq documentation I think Machinekit use:
> > 
> > On the wire, ZeroMQ messages are blobs of any size from zero upwards that
> > fit in memory. You do your own serialization using protocol buffers, 
> > msgpack,
> > JSON, or whatever else your applications need to speak. It�s wise to choose
> > a data representation that is portable, but you can make your own decisions
> > about trade-offs.
> > 
> > > Internally the data is represented by a tree of structures. Only the
> > > compiler knows exactly how those structures translate to actual memory.
> > > One change to one structure will affect the positions of all of the data
> > > after that structure. Generally everything in LCNC is compiled at the
> > > same time using the same specifications so it does not matter. If you
> > > start mixing versions or trying to reverse engineer that blob you are
> > > very likely to end up with something that breaks very easily. I ran into
> > > this problem when I made a Linux version of my Scanything application.
> > > It's distributed separately from LCNC so I ended up distributing it with
> > > a bunch of modules built from common LCNC releases. If none of those
> > > modules match your specific LCNC version it tries to automatically build
> > > a new module based on your version. Of course this only works if it can
> > > find the header files for your build.
> > 
> > At the top you claim "Internally the data is represented by a tree of
> > structures." and this is also what I found in stat_msg.hh file. I do not 
> > think
> > this change between versions. It is common to have some kind of structure,
> > CANopen and TCP/IP or UDP/IP have it. I do not think these structures are
> > supposed to change between version or different compiles.


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Re: [Emc-users] [Emc-developers] Looking to make hex offset list for NML status shared memoryr

[N]

> On 17/02/2020 18:15, Johannes Fassotte wrote:
> > I'm reviewing currently available documentation from the NIST on how a 
> > remote user is fed status information. From what I can tell based on 
> > my experiments is that the raw data file is sent to the remote for 
> > decoding and that the remote is able to do that without issues for the 
> > entire status data set.
> 
> Yes, that is correct.
> 
> >
> > Thus Im thinking that the location of each item withing the data set 
> > is stable for a particular configuration. If structure lengths are 
> > changed or new ones are added via a update then NML has that 
> > information available within itself and it should be able to be pulled 
> > out for use by a remote user to allow proper decoding of the raw 
> > status data it receives.
> 
> The status messages don't contain any type or size information. They are 
> just anonymous blobs of data. Both the source and the destination have 
> to be using the same specification or bad things happen. This is one of 
> the things the Machinekit project wanted to fix.

From the zeromq documentation I think Machinekit use:

On the wire, ZeroMQ messages are blobs of any size from zero upwards that fit 
in memory. You do your own serialization using protocol buffers, msgpack, JSON, 
or whatever else your applications need to speak. It’s wise to choose a data 
representation that is portable, but you can make your own decisions about 
trade-offs.

> Internally the data is represented by a tree of structures. Only the 
> compiler knows exactly how those structures translate to actual memory. 
> One change to one structure will affect the positions of all of the data 
> after that structure. Generally everything in LCNC is compiled at the 
> same time using the same specifications so it does not matter. If you 
> start mixing versions or trying to reverse engineer that blob you are 
> very likely to end up with something that breaks very easily. I ran into 
> this problem when I made a Linux version of my Scanything application. 
> It's distributed separately from LCNC so I ended up distributing it with 
> a bunch of modules built from common LCNC releases. If none of those 
> modules match your specific LCNC version it tries to automatically build 
> a new module based on your version. Of course this only works if it can 
> find the header files for your build.

At the top you claim "Internally the data is represented by a tree of 
structures." and this is also what I found in stat_msg.hh file. I do not think 
this change between versions. It is common to have some kind of structure, 
CANopen and TCP/IP or UDP/IP have it. I do not think these structures are 
supposed to change between version or different compiles.


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Re: [Emc-users] Open source CNC architecture

[N]

> > Go for it. If you design the board the LinuxCNC developers would be very
> > willing to help you integrate it with LinuxCNC. Of course you'll have to
> > be able to produce it at a price that makes it attractive to buyers.
> >
> 
> No.  do not produce yet another board.   You want to use an existing one.
> There are so many in the under $20 range and even under $5.

Tried to provide the best help I had time for to someone yesterday working with 
NML. You could start there, once it is split so that it works over the network 
it should possible to put on one of these readily available cards. Tried to 
split once and think old TK worked but not new axis. Agree, use an existing 
board.

You have looked at how the different parts in Linuxcnc communicate?


> Any STM32 based development board can connect to a Linux PC using USB, SPI
> I2C or whatever then the board will have a dozen or two or more pins.  It
> will also have some useful hardware for making pulses and such.

They are really good and might work as is. Also use a lot less space than an 
old PC/laptop and are most probably also cheaper though in a lot of cases space 
for a computer is not an issue.


Regards Nicklas Karlsson


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Re: [Emc-users] Open source CNC architecture

[N]

> ...
> >> I guess what I am suggesting is that it's time for LinuxCNC to be 
> >> broken apart and a standardized interface for Ethernet control be 
> >> developed.  Once that could talk to dumb FPGA devices like the 7i92H 
> >> or to full blown standalone CNC controllers that can act as simple 
> >> DRO/Power Feed or even simple G-Code like the 3D printers.  Or be 
> >> connected to the much more powerful LinuxCNC to add, in addition to 
> >> G-Code the fancy tool changing apparatus along with robotic cells that 
> >> load and unload the parts.
> > 
> > You are completely missing the point. You don't need to 'break apart' 
> > LinuxCNC. It is designed from the ground up to be modular.

Yes as is now there is NML between the parts.

> 'break apart' is architectural change just like it happened to so many 
> GNU-Linux services or programs. Robotics is one of the closest functions 
> to CNC. Some robots depend on RT kernel but do not have or need GUI on 
> top of it.

Have some robots and thought maybe Linuxcnc could be used for these. Then one 
of these small boards would be nice if running without a GUI but for 
programming connect via TCP/IP which in practice almost certainly will be 
Ethernet or maybe WiFi from an ordinary computer with a GUI I would guess is 
the choice.


Regards Nicklas Karlsson


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Re: [Emc-users] Open source CNC architecture

[N]

> While I don't have a problem with separating the motion control and the HMI 
> hardware.  (it is how most commercial CNCs have done it for the past 30 years 
> or more.)

Have an old Sodick wire EDM built this way and think it is a rather good idea 
though which components are readily available is also important, currently run 
both motion control and HMI on ordinary computer.

> But being more like a printer isn't a good thing.  I've used CNCs whose 
> controls are set up very similar to how a printer works, and frankly they are 
> a giant pain in the ass to use compared with a conventional CNC.  (The 
> manufacturer of those routers mostly makes large format printers and stuff 
> for the sign industry.)  While it kind of sucks on a sign router, I think 
> that system would be almost totally unworkable on a cnc mill.  Just about the 
> only reason those 3 routers haven’t had a brain transplant to convert them to 
> Linuxcnc, is the half a terabyte of existing code already set up for the old 
> proprietary system, and doesn't use g-code and can't be easily ported to a 
> different system.  (Well, I've actually converted one of them but It's old 
> control can still be plugged back in and used, but that wouldn't be possible 
> with the other 2.)  It is hard to ash can that many man hours of setting up 
> machine files (nearly 20yrs of accumulation.) 

Planned to use machine more or less CNC machine as a printer but have no 
experience at all yet. Use CAD software on computer to make drawing and 
generate g-code and then run it on the CNC machine though user interface as is 
now should if not always at least be available then needed.


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Re: [Emc-users] Open source CNC architecture - open source complexity OT, more off it

[N]

> > There are plenty and quite many scientific articles available for free on 
> > Internet. Universities at least have some check, quite often a written Exam 
> > before course could be passed, a little hard to check what kind of 
> > books/articles someone have read and even more so what they might have 
> > learned.
> 
> There is a difference between knowing something and passing exams. Who 
> would you trust more? Someone who is self taught and has recent 
> experience or someone who passed the exam 10 years ago and has never 
> touched the subject since?

Depends if they have read the necessary literature, even a welder or carpenter 
need to read some literature (read a little bit about welding), if they still 
have books they might learn fast again. In Sweden I think it is possible to get 
into university using proven knowledge/competence but it seldom or never happen.

> If you need proof of someone's competence then test results are indeed a 
> reasonable indicator, as long as those results are relatively recent. In 
> that case there is nothing stopping the self taught person from taking 
> the tests. Anyone who passes the test has the required knowledge to pass 
> the test, no matter how they learned it. Of course you are relying on 
> the test asking the right questions.

If you learned once it will be must faster next time. Used Java in programming 
course at University, read books about C/C++ and used it professionally then 
needed for 10 years, many of the concepts are similar but I had not been able 
to learn without reading the books.

> > Met this attitude then working, "it will all be fine if we just get the 
> > project".
> 
> No, that's just putting your head in the sand and hoping for the best.

Major problem is ass sticking out in comfortable height.


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Re: [Emc-users] about NML - RCS_CMD_CHANNEL/EMC_CMD_MSG - EMC_AUX_ESTOP_ON

[N]

> @ John Dammeyer
> 
> I'm quite sure that labview project at least work great  the difficult
> is study lcnc code (write in a good way but not rich of comment ... on the
> other hand, I agree not to comment too much on his code)

Something adding some comments to code then you read it?


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Re: [Emc-users] trying to connect a encoder from cnc spindle motor to schiender vfd --> (sin, cos) resolver

[N]

On Fri, 14 Feb 2020 08:14:18 -0800
Chris Albertson  wrote:

> Looking at the PDF, It seems I forget to ask one question about the signal:
>  Is the sin/cos signal single-ended or differential?   In other words is it
> referenced to ground or do we get pins with labels like sin+ and sin-

These kind of signals is usually used for resolvers, very common on servo 
motors, there are special chips available to excite and decode this, PGA411 is 
one. Be aware that there might be some kind of delay in signal decoding, think 
you could get a transfer function for this, if signal is 10kHz I would guess at 
least one full period is needed to track signal with good accuracy. Analog 
devices have some with 16 bit resolution per turn, expensive for an integrated 
circuit but maybe not compared to machine guess it depend on accuracy of 
machine.


Regards Nicklas Karlsson


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Re: [Emc-users] trying to connect a encoder from cnc spindle motor to schiender vfd

[N]

> On Friday 14 February 2020 02:01:08 andrew beck wrote:
> 
> > Chris.  I'm still learning electronics.  Could you expand a bit on
> > this please.
> >
> > Maybe draw a napkin sketch of it.  Sorry to be a bit slow on the
> > uptake
> 
> I'm not Chris, but the word quadrature means two signals that change 
> state like this at a steady speed
> 
> logic +
> signal A, logic -
> 
>     logic +
> ____signal B. logic -

Very common, very common and if I remember correct RS422 circuits may be used 
to decode this signal, schmitt triggered inputs might be good.

> ...
> 
> This type of encoder signal never skips a count even after millions of 
> direction changes. ...

Well, there is usually plenty of noise in power electronics even with 
differential input signals schmitt triggered inputs might be needed. Checking 
encoder counts at zero pulse is of course a good idea.

> And its cheap to build in hardware or software but 
> the  software version will have a speed limit much slower than the 
> hardware version, but even that can work on a smallish mill at up to 30 
> or so inches a minute, with only a parport breakout board driving the 
> machines motors.

The counter in Micro controllers usually have encoder mode for this purpose, 
it's cheap though a fast differential receiver may be more expensive than Micro 
controller but it's more because they are cheap and not that many dollars or 
whatever currency you count.


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Re: [Emc-users] Open source CNC architecture

[N]

On Fri, 14 Feb 2020 22:04:51 +
Todd Zuercher  wrote:

> Retrofitting  a CNC machine is comparable to retrofitting the drive train of 
> an automobile (or even just it's control systems).  Doing so in a modern car 
> requires quite a lot more technical knowledge than doing so with a vehicle 
> from 50 years ago. ...

Just thru out all junk and connect pedal to motor velocity control.


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Re: [Emc-users] Open source CNC architecture --> printer driver postscript <-> g-code

[N]

Printers talk postscript while CNC machines talk g-code, well not always but 
quite often.


> As an example look at the two articles in December and February Circuit 
> Cellar Magazine by Raul Alverez-Torrico on building a 4-DOF robotic arm.
> https://circuitcellar.com/
>  
> He uses Matlab to do the kinematics (described in the Feb issue) but uses his 
> own serial protocol for moving each motor through an angle.  (Figure 1)
> 
> He uses Matlab to do the kinematics (described in the Feb issue) but uses his 
> own serial protocol for moving each motor through an angle.  Figure 5.
> It could just as easily have been G-Code.Or he could have used a program 
> to interpret his special commands and translate them into G-Code and then run 
> an arm via LinuxCNC.  

Used Simulink/Matlab and what's good with Simulink is it show signal flow but 
it's a delusional target. Get feeling it is all easy but to understand how the 
to set the gain in feedback or other calculations there is no other choice than 
read the theories behind. Basic operations are more or less algebra unless you 
have blocks someone else already wrote and I find most often equations are 
easier to read in textual form especially if they have nice typesetting, would 
be interesting with a programming language allowing variable named formatted 
with LaTeX typesetting.

Simscape or Modelica might provide more help as you could draw ordinary 
schematics instead of manually entering equations as is done in Simulink. To 
calculate feedback gains transformation of these schematic to state space form 
which may be linearised to linear state space form if needed is very useful. 
There are plenty of literature available for linear state space form which is a 
more or less standard form to model dynamic systems so it is very useful.

> The point is that he's using a small UNO for the embedded controller and a PC 
> for the trajectory planning.
> John Dammeyer

Real time in UNO and others in PC?


Regards Nicklas Karlsson


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Re: [Emc-users] Open source CNC architecture --> steam engine no, pyrolis yes, OT!

[N]

> And you? You think that doing things the same old way is better? Steam 
> engine driving machines with pulley transmission in your work shop?

As I understand it steam engine does not have the best efficiency, pyrolysis 
and compression ignition is probably better, maybe some steam in a compbined 
cycle. Swirl chamber to keep formation of Nox pollution to a low level.

> When I was little, we had to pull the weeds by bare hands on a small 
> farm. Our family would prefer doing it this way:
> https://agerris.com/
> https://farmwise.io/
> https://www.deepfield-robotics.com/en/

Think this and car driving itself home from pub might be really good uses of 
artificial intelligence.

> Rafael


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Re: [Emc-users] Open source CNC architecture --> printer driver postscript <-> g-code

[N]

> On Sat, 15 Feb 2020, 19:41 N,  wrote:
> 
> > Printers talk postscript while CNC machines talk g-code, well not always
> > but quite often.
> >
> 
> And just as some folk hand-write G-code, I know a chap who habitually
> creates graphics in raw postscript.

Metoo almost, sometimes use LaTeX for documents then they have measurement data 
so that I do not have to add this manually. For G-code I thought the CAM module 
in the CAD was the choice unless maybe if it is something simple.


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Re: [Emc-users] need a patch tut

[N]

On Tue, 14 Jan 2020 13:26:07 -0800
Chris Albertson  wrote:

> You are applying 300 patches all at once?  The chance of that working
> is about zero.

Or you are the most lucky programmer ever.


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Re: [Emc-users] OT - simple motor wiring

[N]

> > On 21 Jan 2020, at 18:30, Jon Elson  wrote:
> > 
> >  The black-red winding has huge inductance -- HALF a Henry!
> 
> It is a 3W 120V motor. It’s going to eat milliamperes.

Maybe not to few, I would expect low efficiency.


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Re: [Emc-users] looking for advice on best wiring practices and grounding on cnc mills

[N]

Current used to power device will cause some voltage drop in ground so grond 
potential at device will be higher. Ground potential will also vary with power 
used by device. This higher potential might cause a problem if there for 
example is digital communicatin between devices.

> A ground loop is then a single device is connected to ground more than
> once.   A good example is a motor driver.   It might in a "power"
> input called "+" and "-" with the minus side grounded to the AC mains
> ground or a chassis frame ground.   The in addition there is a
> logic level control signal that is "signal" and "ground" wires.
> This is a classic gound loop.
> 
> How to break it?  Use optical isolation on the signal.  This places an
> air-gap in the control signal.
> 
> Most of the time the system is not so simple as the above but the
> concept is the same, multiple ground connections are not good.   Why?
> Because in theory current can flow if you have a loop but can never
> flow if there is not a closed loop.  Then Ohm's law applies -- if
> there is current flow there is voltage drop.   If the voltage drops
> across a gound then you have tow "grounds" that are not the same
> voltage.   This can be really serious if the motors are large.
> 
> There are a number of conventions that work. but they all do the same
> thing, they reduce the number of ground connects to one per "part" of
> the system.
> 
> All the rules try to do the same thing, connect nuetral to ground ONLY
> at the building service entrance, use opto's on all signal lines.
> It is all the same idea
> 
> 
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Re: [Emc-users] X Axis oil passages

[N]

> > From: Andy Pugh [mailto:bodge...@gmail.com]
> > > On 25 Dec 2019, at 08:32, John Dammeyer <  
> > > jo...@autoartisans.com>
> > wrote:
> > >
> > > But how do I block the slot so the oil doesn't fall off the edge.
> > 
> > Maybe drill a hole normal to the surface and push in a peg. Maybe plastic,
> > possibly iron carefully blended.
> > 
> Any suggestions on the type of plastic?  Nylon maybe?

For rubber I am pretty shure nitril is the right choice for plastic I have no 
idea though I am not certain all plastics like oil. Nylon which is a polyamide 
may absorb water which might not be a problem, pretty sure it will grow in size 
if this happens, remember hard to move lever for tractor hydraulics there  I 
used a file to enlarge hole a little bit.


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Re: [Emc-users] looking for advice on best wiring practices and grounding on cnc mills

[N]

> On Thu, 26 Dec 2019 at 19:03, Chris Albertson  
> wrote:
> 
> > All the rules try to do the same thing, connect nuetral to ground ONLY
> > at the building service entrance
> 
> Off-topic, but that isn't the only way to do it.
> https://en.wikipedia.org/wiki/Earthing_system
> Is an interesting read.

Maybe the method with a resistor on protective earth could be rather safe if 
limited to below dangerous level but it will not blow fuse so some eath leakage 
detector is needed. Normally idea is broken conductor come in contact with 
protective earth blowing the fuse but it will not help if you come in contact 
with a conductor, prefer to stay away from grounded equipment then working with 
high voltage because of this.


Regards Nicklas Karlsson


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Re: [Emc-users] looking for advice on best wiring practices and grounding on cnc mills

[N]

No. I am talking about voltage drops in cables used to power devices. It might 
also be AC impedance is rather high at frequencies used for communication and 
device use power in smaller or larger bursts.

Problem is there is voltage drop in cable used to power DC and/or AC but no or 
to be exact neglible voltage drop in cables used for communication in between 
devices.


> I think you are confusing ground and neutral. Ground should never
> move off zero.   But the neutral can be up to about 5 volts above
> ground.
> 
> On Thu, Dec 26, 2019 at 2:26 PM N  wrote:
> >
> > Current used to power device will cause some voltage drop in ground so 
> > grond potential at device will be higher. Ground potential will also vary 
> > with power used by device. This higher potential might cause a problem if 
> > there for example is digital communicatin between devices.
> >
> > > A ground loop is then a single device is connected to ground more than
> > > once.   A good example is a motor driver.   It might in a "power"
> > > input called "+" and "-" with the minus side grounded to the AC mains
> > > ground or a chassis frame ground.   The in addition there is a
> > > logic level control signal that is "signal" and "ground" wires.
> > > This is a classic gound loop.
> > >
> > > How to break it?  Use optical isolation on the signal.  This places an
> > > air-gap in the control signal.
> > >
> > > Most of the time the system is not so simple as the above but the
> > > concept is the same, multiple ground connections are not good.   Why?
> > > Because in theory current can flow if you have a loop but can never
> > > flow if there is not a closed loop.  Then Ohm's law applies -- if
> > > there is current flow there is voltage drop.   If the voltage drops
> > > across a gound then you have tow "grounds" that are not the same
> > > voltage.   This can be really serious if the motors are large.
> > >
> > > There are a number of conventions that work. but they all do the same
> > > thing, they reduce the number of ground connects to one per "part" of
> > > the system.
> > >
> > > All the rules try to do the same thing, connect nuetral to ground ONLY
> > > at the building service entrance, use opto's on all signal lines.
> > > It is all the same idea
> > >
> > >
> > > ___
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> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> >
> > ___
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> 
> 
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Re: [Emc-users] disconnect .var file

[N]

Have a line in my filename.ini file like the one below, where filename is 
whatever name of your configuration files have.
  HALFILE = filename.hal


> Hello!
> Can I somehow disconnect .var file?
> Is it possible ?
> 
> To replace it:
> 
> #!/bin/bash
> 
> rm /home/cnc/linuxcnc/configs/test/sim.var.bak
> rm /home/cnc/linuxcnc/configs/test/sim.var
> 
> sleep 3s
> linuxcnc  /home/cnc/linuxcnc/configs/test/test.ini
> 
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Re: [Emc-users] Backing up an old drive

[N]

You most probably backup data, in Linux the "/home" folder including all 
subdirectories. Not sure if it is possible to save a list of installed packages 
in Linux.

CD-ROM is cheapest if there is enough space, DVD is larger and magnetic tape 
provided you use modern tape drive is the largest.


> All,
> 
> I have EMC2 2.3.0 running on Ubuntu 8.04LTS and it is driving a desk-top
> CNC machine.  I know, pretty old stuff.  But it is running fine and I am
> starting a project that will last a month, or so.  I just noticed the
> hard-drive is making noise/vibration and wonder if it will make it through.
> 
> I think it would be great if I could make an image of the disk and copy it
> onto another.  That way I could swap it out quickly and finish the
> project.  Is this doable with an old OS?  I have everything from WinXp to
> Win10 and Ubuntu 8.04 to 16.04 running in the shop, so I can use another
> computer to make and copy the disk images.  Any and all suggestions are
> welcome!  Thanks.
> 
> PS: I do have back-up CD's but I think it could take awhile to build an old
> OS and old EMC2 software.  Besides, all the OS libraries are archived by
> now and could be hard to find.
> 
> Best regards,
> -- --
> Glenn
> 
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[Emc-users] Small torque, spindle gear box clutch?

[N]

Try to run spindle motor om a machine today, this is my first CNC machine so I 
am a little bit uncertain. Motor run but spindle does not, there of course is a 
possibility gear box i broken but in such case I would have expected noise, 
there is some torque on spindle make it move slowly but not normal.

There some kind of electrical connection. Anybody have any idea if it is common 
to have some kind of clutch for spindle?


Regards Nicklas Karlsson


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Re: [Emc-users] Easy to heat treat high speed tool steel

[N]

> Thank you Dave, for bringing this tough steel to our notice.
> 
> In the fact sheet on the steel, the thing I checked first was the End Milling 
> section.
> 
> Cutting Parameters  High Speed Steel   Carbide: Insert
> Carbide: Solid
> 
> metres/minute  8 to 12110 to 160  
>  60 to 80
> Feet/minute   26 to 40  360 to 525
>200 to 260
> 
> Very different from the 100 fpm in school, and 250 fpm in a machine shop,
> for free cutting steel wen using High Speed Steel.
> 
> 
> The choice of steel depends on what you can buy, what you are making, and 
> what you are doing.

Have some inch thick or similar steel plates at my work place used as dead 
weight. No idea about the quality but it look more expensive than needed.


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Re: [Emc-users] Small torque, spindle gear box clutch?

[N]

> On Sun, 12 Apr 2020 at 16:09, N  wrote:
> 
> > There some kind of electrical connection. Anybody have any idea if it is 
> > common to have some kind of clutch for spindle?
> 
> Yes. My lathe, for example, has a 2-speed gearbox that contains two
> electromagnetic clutches and an electromagnetic brake.

This one is a CNC machine. There is some kind of electrical connection but to 
tell what kind of signal is needed is not obvious, maybe with some luck I did 
not remove cable in other end.


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Re: [Emc-users] linuxcnc on modern hardware

[N]

> On 19.04.20 20:05, N wrote:
> > Plenty available cheap and no reason to user newer.
> 
> I cannot order legacy parts through my local parts distributor.

? Don't have to, if computer break down I get a new one. Throw away two broken 
monitors a while ago and a broken computer a few years ago but mostly they work 
fine. Other parts may however be a problem.


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Re: [Emc-users] linuxcnc on modern hardware

[N]

> Hi,
> For reasons I dont understand, many people prefer to use extremely legacy
> hardware to run linuxcnc.

Plenty available cheap and no reason to user newer.


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Re: [Emc-users] Small torque, spindle gear box clutch?

[N]

Already cut cable and thrown away the old control box. Measured 38ohm, decided 
to try 24 volt, got about 1A current, a small clonking sound and then rotating 
chuck is was connected to motor.

> My lathe internally provides 24 V DC for these clutches at about 1.5 
> Ampere each. Try measuring the voltages in the electric cabinet.
> 
> Peter
> 
> Am 12.04.2020 um 20:48 schrieb N:
> >> On Sun, 12 Apr 2020 at 16:09, N  wrote:
> >>
> >>> There some kind of electrical connection. Anybody have any idea if it is 
> >>> common to have some kind of clutch for spindle?
> >> Yes. My lathe, for example, has a 2-speed gearbox that contains two
> >> electromagnetic clutches and an electromagnetic brake.
> > This one is a CNC machine. There is some kind of electrical connection but 
> > to tell what kind of signal is needed is not obvious, maybe with some luck 
> > I did not remove cable in other end.


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Re: [Emc-users] linuxcnc on modern hardware

[N]

> On 4/19/20 11:12 AM, René Hopf via Emc-users wrote:
> > For reasons I dont understand, many people prefer to use extremely legacy
> > hardware to run linuxcnc.
> 
> It's not a preference, it's an artifact of the situation: CNC machines 
> have lifetimes measured in decades, while PCs go from "brand new" to 
> "legacy" within less than one decade.

Think the one to the left on my desktop is about nine years and I still use it 
daily. Never had a computer this long before, maybe the "boom" times are over.

> I have a Bridgeport that was made in 1983.  Chris and I retrofitted it 
> from its original controller to LinuxCNC in 2010.  We used a random PC 
> we had lying around that had decent RTAI performance - not a brand new 
> top-of-the line one, but not anything legacy or obsolete at the time. 
> It's got a single-core 32-bit Pentium 4 processor.

As I do to but usually have a bit newer laying aound. Have a few with SSD disk, 
they start really fast.


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Re: [Emc-users] Suggestions for encoder cable?

[N]

On Fri, 10 Apr 2020 01:05:03 +0100
andy pugh  wrote:

> On Fri, 10 Apr 2020 at 00:58, Todd Zuercher  wrote:
> >
> > I've liked the cables I've gotten from Igus.
> > https://www.igus.com/product/1074
> 
> This looks good for a dedicated encoder cable:
> https://www.igus.com/product/1117

Without doubt, it must be an excellent cable. Ordinary Ethercat is good but 
maybe voltage drop will be a problem for power supply.

> (and is available by the meter.)
> 
> I think that Igus will also put the connectors on?

Looked at this connector before, it is a good connector but expensive. Are not 
sure about any standard encoder cables but D-sub is readily available, really 
good and guess they are cheap.


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[Emc-users] Machine accuracy

[N]

Finally got things running well today.

According to scale then moving to point at standstill accuracy is around a few 
micrometers for table and a few times more in "Z" direction. This corresponds 
to a few encoder pulses for table and a few times more for "Z" direction. Did 
not check check then moving but expect a lot less accuracy then at move, it was 
a little bit cold but not to bad, another time it was dark and then open door 
to get light inside weather also came in, wind and also some snow. Then there 
is of course plenty of other inaccuracies, driving belt, screw, tool bending, 
...

Anyone here have any experience what accuracy is required then machining parts?


Regards Nicklas Karlsson


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Re: [Emc-users] Cheaper than normal FHA-25B

[N]

Pretty sure I read an article about harmonic drives and cycloidal drive from 
local university.


> There are two good tutorials on designing the gears.  Both depend more on
> geometric construction than math.   They first generate some points then
> fit a spine.  I've read this is not-exact but the error can be as small as
> you like.  Just make more points and the spline gets better.
> 
> Going into the design you need to know what reduction you want and the size
> of the pins.  For the pin size just use whatever drill rod you have.
> 
> The second video uses Fusion360. The first one assumes any generic CAD
> system. These are not nearly as hard to design as involute gears
> 
> 
> 
> https://youtu.be/guvatctnjww
> https://youtu.be/jQ6LQBFZXmU
> 
> Robots are a good reason to own a CNC milling machine.   I want one of these
> https://youtu.be/G6fMV1UPzkg?t=76
> Seriously, they are just 12 motors, 12 gear reductions and a big LiPo
> battery.  The motors come from quad-copter drones.
> 
> 
> On Sat, May 16, 2020 at 10:34 PM andrew beck 
> wrote:
> >
> > Hey Chris.
> >
> > That's awesome.  I was just looking at that video lol.
> >
> > Do you know how he is designing these.  I know that the lobes are
> > calculated by a  equation.
> >
> > It would be good to see the equations that go into this and any plug-ins
> he
> > uses etc.
> >
> > I'm quite keen to build one of these.  Like you for robotics or just
> > anything.   And of course my 4th axis on the VMC
> >
> > Regards
> >
> > Andrew
> >
> > On Sun, May 17, 2020, 4:39 PM Chris Albertson 
> > wrote:
> >
> > > Paul Gould is doing good work with these reduction drives.   This video
> > > shows how a triple reduction system works and just how simple it is.
> > >
> > > Note that all the points of contact with the plastic lobes are ball
> bearing
> > > units.This unit is about as complex as they get and it is still
> easy to
> > > see how it works.   But do notice there must be three dozen bearings
> total.
> > > At the end of the video where he spins the drive with the drill you can
> see
> > > the bearings all around the outside of the gear rotate.This is not
> > > required.  Those can be made with pins or you can use a machined ring
> > > gear.
> > >
> > > https://youtu.be/ewoUsVMFWfU
> > >
> > > My use case for these is robotics but there is such a large overlap
> between
> > > robots and machine tools.   I am building both a power steering system
> for
> > > a robot self-drive car and a z-axis for a Harbor Freight mini mill.   I
> use
> > > the same motor and drive electronics for both of these.  The only
> > > difference is the mill uses a 16mm ball screw and the car uses spur
> gears
> > > But the same NEMA23 motor.   Paul is working on walking robots but
> there is
> > > no reason not to use one of his knee joints as an A-axis in a mill.  In
> > > both cases you put a 2000 PPR encoder on it can use closed loop control.
> > >
> > >
> > >
> > > On Sat, May 16, 2020 at 7:53 PM andrew beck 
> > > wrote:
> > > >
> > > > Chris
> > > >
> > > > So do they use some needle roller bearings that run on the lobes or
> > > > something?
> > > >
> > >
> > > ___
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> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> > >
> >
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> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> 
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Re: [Emc-users] Cheaper than normal FHA-25B

[N]

Harmonic drive but they are expensive.

> I've been thinking about 4th axes;
> While motorised reduction drives are readily available, the issue is
> obviously backlash.
> 
> One way to make a zero backlash drive is to use two identical
> gearbox/drives. Place them at opposite ends of the axis, and pit them
> against each other by a few encoder counts.
> So they will track and retain the zero-backlash.
> 
> Of course, the total power available is now less than one drive motor, but
> it is an option to use almost any pair of reduction drives that can be got.
> But there is also the cost of the second servo amp.
> 
> 
> On Fri, 15 May 2020 at 14:11, andy pugh  wrote:
> 
> > The normally appear on eBay at up to 6x this price.
> > https://www.ebay.co.uk/itm/233587431605
> >
> > The B versions have conventional incremental encoders and hall
> > sensors, so are easy to integrate. Lots of torque, zero backlash and a
> > very strong and fancy big crossed-roller bearing make them an
> > almost-complete 4th or 5th axis just needing a bracket and a drive.
> >
> > I have no connection with the vendor, if you order one and receive
> > dolls-house furniture instead don't blame me.
> >
> > --
> > atp
> > "A motorcycle is a bicycle with a pandemonium attachment and is
> > designed for the especial use of mechanical geniuses, daredevils and
> > lunatics."
> > — George Fitch, Atlanta Constitution Newspaper, 1912
> >
> >
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> >
> 
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Re: [Emc-users] timestamp ethernet hardware

[N]

> I think timestamping was a benefit, esp for PPMC.
> 
> I just read about the new Teensy4.1 having ethernet hardware with PTP.
> 
> Then I checked to see if there were off the shelf ethernet cards with 
> PTP ( there are ).
> 
> Is harwdare generated, timestamped packets of use to linuxcnc?

If I remember correct it is useful then adjusting internal clock over Ethernet 
network with high accuracy. Pretty sure it may be used in real time networks to 
keap devices synchronized and may be used distributed so it could be known all 
devices get the same idea about order things are done.

Might be useful in Linuxcnc but do not think it add to much in most 
configurations. Hardware generated time triggered send would however most 
certainly be nice.


Nicklas Karlsson


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Re: [Emc-users] Interesting GUI

[N]

On Sat, 5 Sep 2020 08:08:17 -0400
Mark  wrote:

> On 9/4/20 6:13 PM, John Dammeyer wrote:
> 
> >>
> >> Never said I changed from Mach 3 to LinuxCNC.  I've not owned a Windows
> >> machine for the better part of 30 years.
> > Oops.  Sorry.  For some reason I thought you had.  What I'm looking for are 
> > reasons why perhaps (again other than a dislike of Windows) why people 
> > changed.
> 
> 
> Controller didn't do what they wanted or needed it to do, 
> dissatisfaction with the OS, or any other number of reasons.  I'm not in 
> the market place trying to sell CNC controllers, so I settled on one 
> that worked for me, and happily enough, it had a Linux back end so I 
> wasn't forced to use Windows or a Mac, both of which I dislike.
> 
> 
> >
> >> Doesn't matter to me how many units that Aliexpress sold per year of that
> >> controller.  Wouldn't work on my machine, so I have no need to even
> >> consider it.
> > I understand that.  I think that Chris was basically trying to say the same 
> > thing.  If for example those types of far east controllers were selling in 
> > the thousands that might say a lot about that type of user interface.
> 
> 
> Or that they were cheap and were installed on a tablet that seems to be 
> ubiquitous these days.  Unfortunately, the interface, both input and 
> output systems in the tablets leave a lot to be desired in the context 
> of a machine shop, at least from what I've seen of tablets.  I just 
> don't want to depend on wireless communications to control a machine 
> that can hurt me or someone else or cause other kinds of damage.

Need to send message periodically to keep machine moving and no risk picking up 
noise or signal from somewhere else. Probably need some kind of encryption and 
randomness to solve this. On top of this are the ordinary risk what happen then 
something fails, used long enough and it will sooner or later, at least me 
quite often use things until they break.


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Re: [Emc-users] Interesting GUI

[N]

> On Wed, 2 Sep 2020 at 22:42, Kirk Wallace  wrote:
> 
> > Given enough development time and money, my guess is that a LinuxCNC GUI
> > could be very similar. The only basically new feature is the swipe and
> > gesture touch feature, which Linux/LinuxCNC should be able to use. Or,
> > ... I may be way off base.
> 
> 
> No, I think it is absolutely possible. There may even be programmers
> out there who work on iPad apps who would look at that and say "yes,
> that's pretty simple".
> But I don't imagine it's any of us.

Programming might be simple, to move 4-8 ton heavy machines without spending to 
much money is harder and then they need a dry home with enough power.

Nicklas Karlsson


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Re: [Emc-users] Tool presetter

[N]

On Mon, 31 Aug 2020 14:42:12 -0700
"John Dammeyer"  wrote:

> I have one of these. 
> Fowler 54-575-600 Electronic Edge Finder with Cylindrical Tip, 0.200" Stylus, 
> 1/2" Shank 

Thinking about it there is no need to probe height of part so no need for z 
direction, just have to place tool presetter on known height compared to 
machine vise.


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Re: [Emc-users] Interesting GUI

[N]

> нд, 6 вер. 2020 о 01:35 andy pugh  пише:
> 
> >
> > I wonder if installing NativeCAM by default would be an idea?
> > (the problem there is that it is not part of the LinuxCNC project,
> > it's hosted separately)
> >
> 
> That is a great idea!
> We know that LinuxCNC has almost endless possibilities, but bringing those
> possibilities to work can be cumbersome, and sometimes virtually impossible
> for a novice. And it usually takes a lot of time.
> So most people would like to try, but eventually prefer something simpler...
> 
> Shortly, it would be good to have at least one config where NativeCAM is
> enabled.

Prefer the CAD program for CAM.

Nicklas Karlsson


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Re: [Emc-users] Tool presetter

[N]

> > From: N [mailto:nicklas.karlsso...@gmail.com]
> > On Mon, 31 Aug 2020 14:42:12 -0700
> > "John Dammeyer"  wrote:
> > 
> > > I have one of these.
> > > Fowler 54-575-600 Electronic Edge Finder with Cylindrical Tip, 0.200" 
> > > Stylus, 1/2" Shank
> > 
> > Thinking about it there is no need to probe height of part so no need for z 
> > direction, just have to place tool presetter on known
> > height compared to machine vise.
> > 
> For my CNC router I use a small piece of single sided fibreglass PC board 
> with a wire for a clip lead.  This runs to the Break Out  Board. I clip a 
> ground lead to the tool bit held in the router collet.  Since I can measure 
> the thickness of the PC board with a micrometer I know that if it's sitting 
> on the top of the work or vise jaws or CNC router bed that when the tool bit 
> contacts it and connects that input to ground that I'm a known distance from 
> whatever the plate is sitting on.
> 
> The macro I modified for MACH3 brings the tool bit down and on contact moves 
> back up and logs the Z zero position.  I then disconnect the clip lead and 
> remove the plate.  
> 
> Since the router doesn't have a repeatable tool holder this has worked out 
> really well each time I replace the tool bit.
> 
> With the Mill with the TT holders things have to be different.  It's easy 
> enough to use the same approach though.  All that's needed is one tool/probe 
> in the holder that has a known length.  That once can be then moved down to a 
> PC board plate like the one I use for the router to establish current Z axis 
> 0.
> 
> At this point each TT tool holder with tool can be touched off the same 
> place.  Then taking into account the original probe value the tool table can 
> be updated.  As long as the tools aren't changed in their holders only the Z 
> point has to be recalibrated if things are changed.  
> 
> I have not yet written any sort of tool touch of macros or functions in 
> LinuxCNC.  No idea where to start with that.

Wait on input then immidiately stop and write down position which of course is 
not possible since it will overshoot. Would guess eyeball and let macro move 
very slow will work well.


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[Emc-users] G42 G43 Cutter compensation have to overshoot

[N]

Starting to write some useful G-code I discovered I had to overshoot motion 
then using G42 or G43 tool compensation to approach from the right direction. 
This will produce some extra unneeded motion. Is there any method to get around 
this extra motion approaching from the right direction then using tool 
compensation?

Regards Nicklas Karlsson


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Re: [Emc-users] Tool presetter

[N]

> I have one of these. 
> Fowler 54-575-600 Electronic Edge Finder with Cylindrical Tip, 0.200" Stylus, 
> 1/2" Shank 
> 
>  I use it with the Shumatech  DRO to find edges or the center of something 
> round.  The DRO-350 has a feature for that.  Eventually I'll wire up a cable 
> that can be sensed by LinuxCNC to detect the edge automatically.

Was also thinking about a cable, however need to connect it each time otherwise 
tool changer will slowly turn it into a twisted cable. Expect they are more or 
less equally good as 3D taster but much cheaper.

> It won't help me set up the tool height for a tool table.  I have a bunch of 
> TT type tooling so eventually I'll need something for detecting where the 
> tool is.  Probably some sort of spring loaded contact that is a precise 
> distance from where it's set.

Was thinking spring loaded, spring only because of tool crash into part, Nissin 
have very accurate wit LED but I have also seen with cable.


Regards Nicklas Karlsson


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Re: [Emc-users] Tool presetter

[N]

> I have one of these. 
> Fowler 54-575-600 Electronic Edge Finder with Cylindrical Tip, 0.200" Stylus, 
> 1/2" Shank 
> 
>  I use it with the Shumatech  DRO to find edges or the center of something 
> round.  The DRO-350 has a feature for that.  Eventually I'll wire up a cable 
> that can be sensed by LinuxCNC to detect the edge automatically.
> 
> It won't help me set up the tool height for a tool table.  I have a bunch of 
> TT type tooling so eventually I'll need something for detecting where the 
> tool is.  Probably some sort of spring loaded contact that is a precise 
> distance from where it's set.

Found a tool length presetter today. The Fowler you are referring to, happen to 
know if it also detect in z direction?

There are plenty of cheap LED beep edge sensor, around 5µm claimed accuracy so 
I will try one of these. Would however prefer to also have z-axis edge detector 
to measure height of work piece compared to tool setter.


Regards Nicklas Karlsson


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[Emc-users] Cutter compensation

[N]

First thing I noticed then reading about cutter compensation is some use 
G41,G42 while Linuxcnc use G42,G43 for different side of cutter.

Sometimes I get a little bit confusing moves. Turning off cutter compensation 
with G40 and move in one direction only and it seems to decompensate in other 
direction. Happen to know if these are well defined for all cases? Or if there 
are any issues?


Regards Nicklas Karlsson


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Re: [Emc-users] Cutter compensation

[N]

Could change cutter diameter and program still works but this should be the 
only advantage.

Used CAM module, "path workbench" in Freecad, not sure if I made some error but 
it did not work well for me. Simple path, should have an arc in each corner. It 
upper right corner it decided some kind of pecking cycle was a good idea, 
drilling an arc of tightly space holes. Source is available so it should be 
possibe to do something about it and think the back is good.

> Is it any advantage in using cutter compensation when programming the
> g-code using CAM? Because since I've started working with CAM for my
> turning programs I like to let the software do all the compensation. By the
> way, I'm talking only about lathe programs. I don't know if this could be
> an advantage for the mill machine user.
> 
> El lun., 7 sept. 2020 a las 16:51, N ()
> escribió:
> 
> > > On Mon, 7 Sep 2020 at 20:20, N  wrote:
> > > >
> > > > First thing I noticed then reading about cutter compensation is some
> > use G41,G42 while Linuxcnc use G42,G43 for different side of cutter.
> > >
> > > I don't think so. G43 is cutter _length_ compensation.
> >
> > Yes reading again, work to long days and are probably to tired, don't know
> > why I mixed them up. Though still got some confusing movements.


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Re: [Emc-users] Cutter compensation

[N]

> On Mon, 7 Sep 2020 at 20:20, N  wrote:
> >
> > First thing I noticed then reading about cutter compensation is some use 
> > G41,G42 while Linuxcnc use G42,G43 for different side of cutter.
> 
> I don't think so. G43 is cutter _length_ compensation.

Yes reading again, work to long days and are probably to tired, don't know why 
I mixed them up. Though still got some confusing movements.


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Re: [Emc-users] cnc axis "Touch Off"

[N]

There are two buttons "Touch Off" and "Tool Touch Off". You always use the same?

> Jon,
> 
> I wrote a bunch of wizards for my mill and my lathe. I use one coordinate 
> system for the origin of the main part and a different origin for each each 
> wizard as it is called so that the wizard works with respect to the/an 
> origin. It makes the math in the wizard much simpler, especially when you are 
> doing something like rotating a rectangle.
> 
> Alan
> 
> > From: Jon Elson 
> > Subject: Re: [Emc-users] cnc axis "Touch Off"
> > Date: September 10, 2020 at 9:04:23 PM CDT
> > To: "Enhanced Machine Controller (EMC)" 
> > 
> > 
> > On 09/10/2020 08:28 PM, R C wrote:
> >> I figured out the "touch off", and that it 'works' the same as homing, 
> >> functionally.
> >> 
> >> 
> >> I wondered what all the different coordinate systems are for, their 
> >> differnces.
> >> 
> >> (I know what a coordinat system is, mathematician here.)
> > This allows you to set up an offset from a main coordinate system, for 
> > instance if you have several identical features to be machined on a part, 
> > one hunk of G-code could machine each part and then set up the offset to 
> > machine the next instance.
> > 
> > It can also be used if you have several parts mounted in a fixture, one 
> > coord system for each part.
> > 
> > Jon
> 
> 
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Re: [Emc-users] LinuxCNC legacy or future

[N]

> ...
> Another comment was negative towards python.

That was me. Prefer languages with static datatypes then possible, one reason 
is then using static datatypes it is possible to check if pieces fit together 
before program is run, this is usually done by compiler. There are also a few 
other reasons.

 ...
> All programmers should have good knowledge of computer history (1970s to 
> late 1990s) before they are allowed to write code for use in production 
> environments. Programs would be way more efficient, easier to debug or 
> troubleshoot, etc.

Might be. Some knowledge about dynamic/static datatypes might be good and 
memory management. Static datatypes I already mentioned above. Then I write 
program I use to keep variables as local as possible, in C and if I remember 
correct ADA it is rather simple to limit scope even within function, for ADA I 
think it is even possible to use dynamic size of locally allocated variables 
like array but I seldom use ADA because of availibility.

> Is LinuxCNC going to stay as it is and end up as other old computer 
> technologies described in IEEE article "Inside the Hidden World of 
> Legacy IT Systems"
> https://spectrum.ieee.org/computing/it/inside-hidden-world-legacy-it-systems

Have been working on a missing piece of Hardware for a few years but start to 
get satisfied with the result now. This also mean I could switch more attention 
to Linuxcnc.


Regards Nicklas Karlsson


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Re: [Emc-users] LinuxCNC legacy or future

[N]

> On Mon, 7 Sep 2020 at 22:31, Rafael Skodlar  wrote:
> 
> > IMO it's extremely bad to attack those who come up with "it would be
> > nice to have this or that" in existing product. Saying, "it's open
> > source, go fork and write your own code" is plain STUPID! We are not all
> > programmers! [1]
> 
> The problem is that not enough of us are programmers. ( I am not a programmer 
> )

I am programmer, main problem is I have to spend my days earn money for my 
living.


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Re: [Emc-users] Another possibly silly Q for Peter or Andy.

[N]

> On 09/09/2020 11:08 AM, Gene Heskett wrote:
> > Is it possible to get an enable signal, per axis, from the mesa cards
> > that would become true, hopefully a couple micky-secs ahead of the first
> > stepper pulse so no missed steps would normally occur, losing its home,
> > and go back false when the last step has been sent? It maybe could be
> > timed right if it actually steps on the trailing edge of the pulse, and
> > the enabling action was on the leading edge.
> >
> >
> This is the TRICKY bit, knowing when an axis is SOON going 
> to start moving.

But it is possible to introduce a delay if needed. Use a translation of time so 
these things that should be done before is done immidiately while the others 
are delayed. Just be aware not to introduce any delay for feedback in control 
loops.


Regards Nicklas Karlsson


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Re: [Emc-users] Cutter compensation

[N]

> On 09/07/2020 03:24 PM, Leonardo Marsaglia wrote:
> > Is it any advantage in using cutter compensation when programming the
> > g-code using CAM? Because since I've started working with CAM for my
> > turning programs I like to let the software do all the compensation. By the
> > way, I'm talking only about lathe programs. I don't know if this could be
> > an advantage for the mill machine user.
> >
> >
> The advantage is you can adjust the size of the part or 
> compensate for tool wear without recreating the G-code.  
> This is less of an issue today than when G-code programs 
> came on punched paper tapes.

For me it still sound like a very good idea fine tuning diameter instead of 
changing the g-code.


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Re: [Emc-users] Interesting GUI

[N]

> On 9/2/20 12:55 PM, andy pugh wrote:
> > Not much of it, but it does make Axis look a little old-fashioned..
> > 
> > https://youtu.be/ZgqCY3gUHcM
> > 
> 
> 
> A little more information:
> > https://www.youtube.com/watch?v=AWVdVtgyldQ

Have monitor on one of my machine on a flexible arm, also have some touch 
screen but this is not one of these. Have my own ideas.


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Re: [Emc-users] Tool presetter

[N]

> On Thursday 03 September 2020 22:23:07 Ken Strauss wrote:
> 
> > > -Original Message-
> > > From: John Dammeyer [mailto:jo...@autoartisans.com]
> > > Sent: Tuesday, September 01, 2020 1:03 AM
> > > To: 'Enhanced Machine Controller (EMC)'
> > > Subject: Re: [Emc-users] Tool presetter
> > >
> > > > -Original Message-
> > > > From: N [mailto:nicklas.karlsso...@gmail.com]
> > > > Sent: August-31-20 9:21 PM
> > > > To: Enhanced Machine Controller (EMC)
> > > > Subject: Re: [Emc-users] Tool presetter
> > > >
> > > > > I have one of these.
> > > > > Fowler 54-575-600 Electronic Edge Finder with Cylindrical Tip,
> > > > > 0.200"
> > >
> > > Stylus, 1/2" Shank
> > >
> > > > >  I use it with the Shumatech  DRO to find edges or the center of
> >
> > something
> >
> > > round.  The DRO-350 has a feature for that.  Eventually
> > >
> > > > I'll wire up a cable that can be sensed by LinuxCNC to detect the
> > > > edge
> > >
> > > automatically.
> > >
> > > > Was also thinking about a cable, however need to connect it each
> > > > time
> > >
> > > otherwise tool changer will slowly turn it into a twisted cable.
> > >
> > > > Expect they are more or less equally good as 3D taster but much
> > > > cheaper.
> > >
> > > Nicklas
> > >
> > > You make a good point.  It should be possible to make some sort of
> > > holder which fits around a TT mill holder shank.  The holder could
> > > have a small
> >
> > Blue
> >
> > > Tooth Low Power module that signals contact.
> > >
> > > The issue might be response time.   Or noise that delays the contact
> >
> > signal
> >
> > > long enough to break the probe.
> >
> > It takes *VERY* little overtravel to destroy the tip of a small
> > carbide endmill. I wouldn't consider touching off onto a plate lacking
> > some sort of movement after contact with the endmill.
> >
> I have used a small bit of pcb material for a G38.2 contact. With the 
> spindle turning backwards, its .0001" accurate and lasts till I goof up 
> and destroy it. It registers contact for TLO setting with .0001"

>From the discussion I conclude electric contact measurement is good and these 
>these cheap edge detectors are probably very good. And even though first time 
>I run machine I made a rather deep dent in a piece of wood with the chuck, I 
>could hear the wood break I make conclusion there is no need for spring if 
>right done with a little bit of care.


Nicklas Karlsson


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[Emc-users] Tool presetter

[N]

Anyone have any experience on where to find a good tool presetter? And/Or edge 
detector?

As tool usually is a rather good conductor and sensor could be made of 
conductive material most obvious would be simple spring loaded contact 
meausurement for both.

I found Nissin have a Centering Gauge Swing Type with very high 
accuracy/repeatability and would guess they use contact measurement but also 
guess they are very expensive since they want customer to ask for price.


Regards Nicklas Karlsson


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Re: [Emc-users] Tool presetter

[N]

> On Mon, 31 Aug 2020 at 18:41, N  wrote:
> 
> > As tool usually is a rather good conductor
> 
> Yes, even carbide.
> 
> >  and sensor could be made of conductive material most obvious would be 
> > simple spring loaded contact meausurement for both.
> 
> I have just spent nearly £8 on one from Amazon as an experiment.

I also found cheap edge detector and touch plate or similar for tool length on 
Amazon, have seen 5µm as claimed accuracy and it's probably good enough for now 
so I will probably try them. At least until I figure out what might be better.


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

CANopen have a special sync message which is used for synchronization. You 
probably want cyclic synchronization communication, messages are sent anywhere 
within communication period and start to be used then synchronization message 
is sent. Synchronization message may have som jitter, it does not interrupt a 
message currently being sent but have hight priority so it will be sent before 
other messages with lower priority, not sure if it may be time stamped to 
increase accuracy if needed.

With cyclic communication receiver know then message is expected and may turn 
off motor if not received as expected, for example if cable is removed. CAN bus 
have small messages which is usually a good choice for real time since it is 
common messages are small but need to be sent often.


> An off topic question, not directly LinuxCNC related...
> 
> How are motors on a serial bus controlled and synchronised?  
> 
> My only real control experience is with LinuxCNC with Mesa and parallel port 
> hardware where commands and feedback and precisely timed.  Sending commands 
> and receiving feedback over a serial link I would expect to cause 
> synchronising problems, and the bandwidth would reduce the update rate.
> 
> How are these issues handled?  I tried googling this, but didn't find much -  
> I wasn't sure what to search for.
> 
> Thanks,
> Frank


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> I think the question was intended to be more theoretical and asks about
> "exactly" synchronizing commands. The LinuxCNC/SPI solution is not
> that.  SPI works only because it is so fast that the error in
> synchronization is tiny and goes unnoticed.

Using a Micro controller it is possible to connect pwm output to CS signal and 
use it to trigger interrupt to send a message, receive may clock input so if 
needed it is possible to get really good synchronization with SPI and standard 
Micro controller if needed. In doubt there is any case this accuracy is needed 
or make a difference in practice but syncronize clock drift may be needed, 
especially if a FIFO is used.

> Here is a harder problem. Let's say I am in North America and by buddy
> lives in Europe and we want to each run clocks and we want them to stay in
> phase at a high level of accuracy.   To make matters worse assume this is
> the mid-1800s and the radio is not yet invented.  They actually solved this
> problem.  The solution was "mutually observed events" and we use this same
> solution today to keep widely dispersed machines in sync.   In the old
> days, they would observe one of Jupiter's moons from both America and
> Europe and assume they both say the moon transit the planet at the same
> time.  Orchestras use a conductor waving a stick who is "mutually
> observed" by all musicians.Same with a CAN bus, you could, if needed
> use a high priority "clock tick" message that all nodes see at the same
> time.

Know about it and it could be sursingly tricky to agree about event ordering.

> But in real-life.   We accept "close enough" and just us a SPI signal that
> is fast enough that no one notices the error.

Agree, used this approach many times and quite often there is plenty of other 
random variations.


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> ...
> On CAN you can take advantage of the fact that all devices read the bus at
> the same time.  Each reader decides what information it wants to read and
> ignore the rest so a time-sync heartbeat could be implemented if the nodes
> all needed to be time synchonized. ...

Yes all devices need to read bus within the time it take to send one bit 
because of the arbitration used to send the message with highest priority 
first. With CAN-FD speed is increased after address is sent so that message 
could be larger.


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> I thought of one bus per leg, but the Raspberry Pi only supports two CAN
> busses and I think this is a common limitation not just on the Pi. But
> I think we just figured out that one CAD FD can do 12 motors at 20 Hz.

It is more or less possible to configure mapping of dictionary into PDOs sent 
in real so I expect values for more than one servo motor could be sent in each 
message, maybe a few. If driver use internal position control loop you could 
send back feedback at a lower rate, looking into standard for CANopen lower 
numbered PDO have higher priority and for each PDO number TPDO have higher 
priority than RPDO while it may make sense to do the opposite if possible to 
send back feedback at a lower rate.


Nicklas Karlsson


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> > > I thought of one bus per leg, but the Raspberry Pi only supports two CAN
> > > busses and I think this is a common limitation not just on the Pi. But
> > > I think we just figured out that one CAD FD can do 12 motors at 20 Hz.
> > 
> > It is more or less possible to configure mapping of dictionary into PDOs 
> > sent in real so I expect values for more than one servo motor
> > could be sent in each message, maybe a few. If driver use internal position 
> > control loop you could send back feedback at a lower rate,
> > looking into standard for CANopen lower numbered PDO have higher priority 
> > and for each PDO number TPDO have higher priority
> > than RPDO while it may make sense to do the opposite if possible to send 
> > back feedback at a lower rate.
> > 
> > 
> > Nicklas Karlsson
> > 
> I think it all depends on what a motor requires. 
> One byte for Enable/Direction/MotionType
> Four bytes for signed position
> Two bytes for Current/Torque/Velocity value?
> That leaves one byte Maybe a max Current Limit value?

In Canopen standard there is. A 16 bit control word index 6040h usually mapped 
to PDO sent periodically. A signed 32 bit position value 607Ah usually mapped 
to PDO sent periodically. It is possible to map other values. It might be 
possible to run drive without mapping to a periodic PDO or a PDO sent more 
seldom but but are not certain it is allowed according to standard and even if 
it is it might not work with the drive. Data sent is normally at least 48 bit 
and payload is 64 bit so there will values for one motor only in each message 
CAN-FD allow longer messages so here it might be possible to squeeze in values 
for more than one drive in each message. Then drives send back feedback each 
drive however neeed to send one message but if drive have internal feedback and 
does not make complain, bugs or other problems these values could be sent back 
more seldom.

> A reply with 6 bytes might be position (4 bytes) and velocity(2 bytes)

In canopen standard there is. A 16 status word index 6041h and 32 bit signed 
integer position actual value which I think is the value usually sent back but 
are not totally certain.

> Both of those messages can't easily be packed into one shared with a second 
> motor.  Not without going to perhaps signed relative position and signed 
> velocity.

You are right they can't in CAN but maybe in CAN-FD but only for values sent to 
drives and not feedback.

> The problem with relative is it turns again into the equivalent of a toggle 
> message.  Miss one and your position is wrong.  So I would never do that.

Agree, almost. It is in most cases possible to use a 16 bit value and keep 
track of the overflows provided it does not move to many counts in between each 
time. It is not uncommon Micro controller have 16 bit encoder counter so 
software need to keep track of overflows, not many rows of code but it must be 
there and work perfect.


Nicklas Karlsson


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> > > The problem with relative is it turns again into the equivalent of a 
> > > toggle message.  Miss one and your position is wrong.  So I would
> > never do that.
> > 
> > Agree, almost. It is in most cases possible to use a 16 bit value and keep 
> > track of the overflows provided it does not move to many
> > counts in between each time. It is not uncommon Micro controller have 16 
> > bit encoder counter so software need to keep track of
> > overflows, not many rows of code but it must be there and work perfect.
> 
> I disagree.  What happens in the processor with encoder and motion output is 
> deterministic and you can use smaller counters and overflow interrupts etc.  
> It's tightly coupled.
> 
> A CAN message sent and ACK'd by _a_ node on the bus will _not_ be 
> retransmitted.  So the target motor that missed it will not know that it 
> missed it nor will the sender.  This is a fundamental issue with the CAN 
> protocol which is why toggle messages are a bad idea.
> 
> So PDO messages in CANopen are useful for information but not for commands 
> unless the commands are absolute.

Agree.

> For example a PDO that contains a SWITCH ON message that is missed and then a 
> short time later contains SWITCH OFF doesn't change the target node.  Just 
> the ON/OFF pulse was missed.  And that's a different problem.

Agree and had some discussions about it sometimes. Sending commands and there 
will be state machines that must be kept in sync. In CiA402 for servo motors 
there are some state machine for control-/status-word and I have not been able 
to put together current state from statusworld, it had been good if possible 
because if states come out of sync something will not work as expected, maybe 
it is possible from current sent controlword and statusword together but I have 
not been able to solve it perfect.

> One could send relative distances to a motor and then also use PDOs to report 
> position/velocity but what does the sender do if the position isn't yet what 
> it expected?  Could be any number or reasons why it's not there yet.  
> Mechanical load, periodic messages that are more often than the rate of 
> change of the motor.

Sending encoder value is an absolute distance but it may overflow so it must be 
sent often enough and it might be often enough even if a limited number of 
messages are missed.


Nicklas Karlsson


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> The way to handle things like overflows in real-world robots is to use
> real-wold units in the data.  The lower level controls on each motor does
> the conversion.   So the motor command is in radians per second and is in
> floating-point.   The encoder reports its angle in radians, in
> floating-point.

No matter what units are used if the number overflow software must keep track 
of it.

To use real world units you must have numbers with decimal point, in CANopen 
values are sent as integers, there are extra entries, scaling factors for units 
used for the values received/sent. It is also possible to send values as 
floating point and this datatype is named real in CANopen but this is less 
common. To use same unit as encoder happen to have have advantage no resolution 
is lost due to rounding.


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> > From: Frank Tkalcevic [mailto:fr...@franksworkshop.com.au]
> > > You subject line says RS485/CAN which are dramatically different from the
> > SPI based synchronous clocked serial interfaces.  Even RS485 and CAN are
> > dramatically different.
> > 
> > Thanks for the replies...
> > 
> > The question was around slower RS485/CAN.  I'm seeing a lot of actuators
> > (motor/gearbox/driver combinations) that are driven by CAN bus (MIT
> > cheetah).
> > 
> > Brute speed seems to be a common solution, which I'm guessing protocols like
> > EtherCAT rely on.
> > 
> > Given the CAN bus speed limits - 1MHz, it doesn't seem possible to
> > send/receive messages to many motors at a typical LinuxCNC 1kHz rate.  Is
> > there some kind of "smarts" that let these control systems work smoothly at
> > lower update rates?
> > 
> Most CAN based Step or Servo motors can operate in position or speed mode.  
> In speed mode you can also set torque values.   They work well for say pick 
> and place or tool changers etc.  And anything else where you might want 
> precision motion or torque control.
> 
> Generally the motors come in two flavours supporting either J1939 or CANopen. 
>  Recall I mentioned that CAN messages have 11 bit IDs and up to 8 data bytes. 
>  To set up or control a motor you send Service Data Object messages (SDO) 
> writing to the device object dictionary (OD).  You get information back by 
> reading from the OD.
> 
> When working with CAN bus it's handy to have some sort of dongle for 
> receiving and sending messages.  Once such device is a CANUSB from Lawicel I 
> Sweden.
> www.canusb.com

And an application to read/write the dictionary using an .eds or .dcf file.


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> Have a read on the manuals for the Yaskawa Legend 01  or 04
> 
> It uses serial at 9600 !!! to command the drive.  (RS232 serial, or
> ethernet interface)
> The trick it uses is to send only new, relevant data, and not fixed packets

Good enough for configuration but not coordinated movement in real time. Most 
drives have digital inputs for on/off, reverse/forward and analog input for 
speed. Guess you need an extra module/card to get a CAN interface.


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