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

2020-02-14 Thread andrew beck 
Andy the EXE box looks like the right price if t will do the job.  I'll
have a look at it.  And all the data sheets etc.

Regards

Andrew

On Sat, Feb 15, 2020, 5:16 AM andy pugh  wrote:

> On Fri, 14 Feb 2020 at 15:29, dave engvall  wrote:
>
> >
> >
> >
> https://www.st.com/content/ccc/resource/technical/document/application_note/group0/6a/82/83/37/61/69/4e/74/DM00497286/files/DM00497286.pdf/jcr:content/translations/en.DM00497286.pdf
>
>
> Resolvers are a different (and slightly harder) problem as they are AC
> output.
>
> The answer almost certainly is an EXE box.
> https://www.ebay.com/itm/303373292470
> For example.
>
> But an Arduino might be a fun project to achieve the same thing.
> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?ResolverToQuadratureConverter
> Is likely to get you close. You do not need any of the excitation signal
> generation code or hardware, though)
>
> --
> 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] Open source CNC architecture

2020-02-14 Thread David Berndt 
On Sat, 15 Feb 2020 01:56:44 -0500, Rafael Skodlar   
wrote:



On 2020-02-11 01:04, Chris Albertson wrote:
   I said people *want* to use CNC like a laser printer. Most  
setups are
not that good.  It is a goal and if designing a new system.  It is good  
to
set the bar high and try to do what can't be done today.What I  
really

meant was that with a printer, all the critical timing happens in the
printer.  There are no servo-loops on the PC and you don't need a  
real-time

OS to print to paper. I think people want CNC to work this way.



That's how some CNC machines work. I came across a small woodwork  
business owner with very nicely garage that was converted into workshop.  
Win PC in the corner for designing parts in CAD, large Axiom CNC machine  
with a pendant to control it. Tiny LCD is all that's needed to select  
the job, i.e. file from a USB stick.


The owner did not know what's inside the CNC machine itself and he  
doesn't care. That's what you say Chris I think and I agree with.


I don't know if there's an option for connecting that CNC machine to  
LAN. I would not use wireless connections for such as it's security  
issue due to hacking possibility in the neighborhood. Another  
possibility is noise on WhyFy frequencies from appliances, bad power  
lines, etc.


In any case, that CNC machine does not have or need a PC computer with  
modern GUI interface connected directly to run it. That's why I started  
this discussion. X-windows is waste of resources, it's another thing  
that needs to be maintained and updated in some instances. Too many  
things to go bad in what's supposed to be a relatively simple embedded  
system.


The tiniest user interface would be possible using extended ASCII  
characters as in old DOS. We used to play with that in old email  
signatures. My fun with ASCII art in the 1990s:




How did we get to the point where we decided that the goal is a  
"relatively simple embedded system"? I for one am not looking to trade off  
the current gui and it's features for what you describe.


It seems like a lot of this thread seems to steer itself in the machinekit  
direction in terms of apparent goals/ideals, so I guess I'd ask, why not  
start there?





 . ..   .  . . . . o o o o O o
   ___   ___   _  O
  |  Rafael Skodlar| |   LINUX   |   ]OO|_n_n__][.
  | ra...@mydomain.com |=|  Support  |=||=[]_|__|)<
   oo~~oo~   ~~oo~~~oo~~  oooo  'oo -| oo\_
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

Add colors, lines, and block characters and ... you see the picture  
that's taking extremely little memory by today standards.
Simple ASCII DRO + G-code scroll window and 4x4 keypad would be enough  
for most work. No need for keyboard, mouse and X-windows on large  
monitor.



On Mon, Feb 10, 2020 at 3:06 PM Bari  wrote:

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.



Why it's not that simple:


https://www.machinedesign.com/3d-printing-cad/article/21122653/top-11-myths-of-cnc-machining


the article states:
Myth #4: G/M Code is a Thing of the Past

That's true too. It amazes me that the industry did not go away from  
primitive code by today standards. G-code was only modified or updated  
by some CNC machines manufacturers as far as I know but most of G-code  
is still the same. Compare that to computer/software advancements since  
1980s. Perl, php, python, Go, html, etc.


Using G-code is like writing computer programs in assembly language! It  
time to upgrade it to something like HP-GL with addition for Z and other  
axis obviously. Such a language would make it much easier for human(e)  
use. 4 to 6 letter long abbreviations for tool manipulation would still  
make code terse enough to fit on smaller LCD displays and we could  
remember the commands for small jobs after a while.


For start, HP-GL commands would need to be modified to accommodate  
relative or absolute CNC tool movement.


Magazine Digital Machinist has some very cool CNC related articles but  
you need to wait long for the next quarterly issue to follow them. None  
of the advertisers mention LCNC ;-(



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Re: [Emc-users] Open source CNC architecture

2020-02-14 Thread Rafael Skodlar 

On 2020-02-11 01:04, Chris Albertson wrote:

   I said people *want* to use CNC like a laser printer. Most setups are
not that good.  It is a goal and if designing a new system.  It is good to
set the bar high and try to do what can't be done today.What I really
meant was that with a printer, all the critical timing happens in the
printer.  There are no servo-loops on the PC and you don't need a real-time
OS to print to paper. I think people want CNC to work this way.



That's how some CNC machines work. I came across a small woodwork 
business owner with very nicely garage that was converted into workshop. 
Win PC in the corner for designing parts in CAD, large Axiom CNC machine 
with a pendant to control it. Tiny LCD is all that's needed to select 
the job, i.e. file from a USB stick.


The owner did not know what's inside the CNC machine itself and he 
doesn't care. That's what you say Chris I think and I agree with.


I don't know if there's an option for connecting that CNC machine to 
LAN. I would not use wireless connections for such as it's security 
issue due to hacking possibility in the neighborhood. Another 
possibility is noise on WhyFy frequencies from appliances, bad power 
lines, etc.


In any case, that CNC machine does not have or need a PC computer with 
modern GUI interface connected directly to run it. That's why I started 
this discussion. X-windows is waste of resources, it's another thing 
that needs to be maintained and updated in some instances. Too many 
things to go bad in what's supposed to be a relatively simple embedded 
system.


The tiniest user interface would be possible using extended ASCII 
characters as in old DOS. We used to play with that in old email 
signatures. My fun with ASCII art in the 1990s:


. ..   .  . . . . o o o o O o
  ___   ___   _  O
 |  Rafael Skodlar| |   LINUX   |   ]OO|_n_n__][.
 | ra...@mydomain.com |=|  Support  |=||=[]_|__|)<
  oo~~oo~   ~~oo~~~oo~~  oooo  'oo -| oo\_
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

Add colors, lines, and block characters and ... you see the picture 
that's taking extremely little memory by today standards.
Simple ASCII DRO + G-code scroll window and 4x4 keypad would be enough 
for most work. No need for keyboard, mouse and X-windows on large monitor.



On Mon, Feb 10, 2020 at 3:06 PM Bari  wrote:


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.



Why it's not that simple:


https://www.machinedesign.com/3d-printing-cad/article/21122653/top-11-myths-of-cnc-machining


the article states:
Myth #4: G/M Code is a Thing of the Past

That's true too. It amazes me that the industry did not go away from 
primitive code by today standards. G-code was only modified or updated 
by some CNC machines manufacturers as far as I know but most of G-code 
is still the same. Compare that to computer/software advancements since 
1980s. Perl, php, python, Go, html, etc.


Using G-code is like writing computer programs in assembly language! It 
time to upgrade it to something like HP-GL with addition for Z and other 
axis obviously. Such a language would make it much easier for human(e) 
use. 4 to 6 letter long abbreviations for tool manipulation would still 
make code terse enough to fit on smaller LCD displays and we could 
remember the commands for small jobs after a while.


For start, HP-GL commands would need to be modified to accommodate 
relative or absolute CNC tool movement.


Magazine Digital Machinist has some very cool CNC related articles but 
you need to wait long for the next quarterly issue to follow them. None 
of the advertisers mention LCNC ;-(


--
Rafael Skodlar


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

2020-02-14 Thread Gene Heskett 
On Friday 14 February 2020 16:30:51 Andy Pugh wrote:

> > On 14 Feb 2020, at 20:55, Gene Heskett  wrote:
> >
> > The coils are usually isolated, with op-amp bias supplied to one end
> > of the coils, so you get sin plus and minus and cosine + and -
>
> I don’t think we are talking about coils here.
>
I was Andy, see the link Dave Engval posted to a pdf from a maker of such 
that described sin/cos encoders well. I've never used one but that was a 
well written tome, including the math I got lost in. What they didn't 
cover to my satisfaction was how they made a single cycle per turn into 
a many cycles per turn with index at the outout. Proprietary stuff 
inside the IC they were discussing, and which some would call magic, and 
which could result in a lag between position and output.  But thats just 
a SWAG since I have zero experience with the care and feeding of such 
critters.

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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Re: [Emc-users] Open source CNC architecture

2020-02-14 Thread Todd Zuercher 
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.  It is a complicated task and no advances in technology I can for 
see are going to change that.   Simply using Linuxcnc doesn't require much 
knowledge about its inner workings or any special skills, no more than running 
any other CNC, and less than many.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Chris Albertson  
Sent: Friday, February 14, 2020 3:54 PM
To: Enhanced Machine Controller (EMC) 
Subject: Re: [Emc-users] Open source CNC architecture

[EXTERNAL EMAIL] Be sure links are safe.

On Thu, Feb 13, 2020 at 11:43 AM Gene Heskett  wrote:

> On Thursday 13 February 2020 12:51:26 Chris Albertson wrote:
>
> > When designing something new one must be VERY careful not to be one of
> > Henry Ford's customers.In an interview, someone asked Henry Ford
> > (Who was famous for saying "You can have the Model T in any color you
> > like, so long as you like black.")Mr. Ford said that if he had
> > listened to his customers that would have told him all they wanted 
> > was a faster horse.
>
> Don't forget Younger women and More money ;-) [...]
> > Back to CNC.   Step back and people just want to make parts, not
> > fiddle with 100 details of how the CNC machine works.  That is 
> > setting the bar really high.
>
> But in a one man shop in a pond full of frogs, I have to either know 
> all that, or pester you kind folks for pointers from the real experts.  
> And I appreciate the brain pool this list is, a lot.
>

No.  You should not need to know anything.  The fact that you do need to is
a sign that the technology is immature.Back when cars were a new and
immature technology drivers had to know what a "spark advance" was and also 
understand the effect of the mixture controls and how to use a clutch and
shift gears.  In 20 years a small child will be able to operate a car
by sitting in the back seat and saying "Take me the gramma's house"

All tech works that way.   At first, it is usable by experts then it gets
easy.   Hobby level CNC has a LONG way to go before it gets easy.

As I pointed out before a good example to follow is "cleanflight". It
lets anyone with minimal tech background configure the software inside a
multi-copter drone and download it onto the chip.They do not need to
even know the system uses an RTOS.  http://cleanflight.com   It is all open
source and is easy to use

There is no good technical reason a CNC machine can't connect to a normal 
desktop computer or phone over WiFi and "just work".




> > I've done this for other projects at work.   The first step is to fly
> > out to where your users live and watch them work.  See what they do 
> > and how they spend their time.  The low-hanging fruit are tasks that
> > take a lot of time but not much brainpower.   User productivity goes
> > up when you automate those tasks.
>
> This is one of the things I have done several times as a tv engineer, 
> look the operation over and see where the big time sink is, and fix 
> it, often with a very low powered computer because it still works 
> faster than a human. But it can replace that human and his reaction 
> times by something many times more consistent with any human that can 
> push a few labeled buttons.
>
> 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] trying to connect a encoder from cnc spindle motor to schiender vfd

2020-02-14 Thread Andy Pugh 


> On 14 Feb 2020, at 20:55, Gene Heskett  wrote:
> 
> The coils are usually isolated, with op-amp bias supplied to one end of 
> the coils, so you get sin plus and minus and cosine + and -

I don’t think we are talking about coils here.

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Re: [Emc-users] Open source CNC architecture

2020-02-14 Thread Chris Albertson 
On Thu, Feb 13, 2020 at 11:43 AM Gene Heskett  wrote:

> On Thursday 13 February 2020 12:51:26 Chris Albertson wrote:
>
> > When designing something new one must be VERY careful not to be one of
> > Henry Ford's customers.In an interview, someone asked Henry Ford
> > (Who was famous for saying "You can have the Model T in any color you
> > like, so long as you like black.")Mr. Ford said that if he had
> > listened to his customers that would have told him all they wanted was
> > a faster horse.
>
> Don't forget Younger women and More money ;-)
> [...]
> > Back to CNC.   Step back and people just want to make parts, not
> > fiddle with 100 details of how the CNC machine works.  That is setting
> > the bar really high.
>
> But in a one man shop in a pond full of frogs, I have to either know all
> that, or pester you kind folks for pointers from the real experts.  And
> I appreciate the brain pool this list is, a lot.
>

No.  You should not need to know anything.  The fact that you do need to is
a sign that the technology is immature.Back when cars were a new and
immature technology drivers had to know what a "spark advance" was and also
understand the effect of the mixture controls and how to use a clutch and
shift gears.  In 20 years a small child will be able to operate a car
by sitting in the back seat and saying "Take me the gramma's house"

All tech works that way.   At first, it is usable by experts then it gets
easy.   Hobby level CNC has a LONG way to go before it gets easy.

As I pointed out before a good example to follow is "cleanflight". It
lets anyone with minimal tech background configure the software inside a
multi-copter drone and download it onto the chip.They do not need to
even know the system uses an RTOS.  http://cleanflight.com   It is all open
source and is easy to use

There is no good technical reason a CNC machine can't connect to a normal
desktop computer or phone over WiFi and "just work".




> > I've done this for other projects at work.   The first step is to fly
> > out to where your users live and watch them work.  See what they do
> > and how they spend their time.  The low-hanging fruit are tasks that
> > take a lot of time but not much brainpower.   User productivity goes
> > up when you automate those tasks.
>
> This is one of the things I have done several times as a tv engineer,
> look the operation over and see where the big time sink is, and fix it,
> often with a very low powered computer because it still works faster
> than a human. But it can replace that human and his reaction times by
> something many times more consistent with any human that can push a few
> labeled buttons.
>
> 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 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

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

2020-02-14 Thread Gene Heskett 
On Friday 14 February 2020 11:14:18 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-

The coils are usually isolated, with op-amp bias supplied to one end of 
the coils, so you get sin plus and minus and cosine + and -

> If there are even 100 pulses per revolution and the spindle runs at
> 100K RPM then we are talking about 1K or 10 MHz.   At that point I
> start thinking about hardware quadrature decoding rather than software
> or in the Linux CNC world they use FPGA chips.

Where would one find a 100k rpm device with an encoder.

> But without understanding the signal it is way to early to even think
> about a design solution.Let's see what's on all the wires first.

IDK about resolvers but the quad in a 5i25 shouldn't have a problem with 
a quad signal at 10 MHz.

> On Fri, Feb 14, 2020 at 7:29 AM dave engvall  
wrote:
> > a bit overdone for your app but this should give you an idea. page
> > down to fig 16.
> >
> >
> > https://www.st.com/content/ccc/resource/technical/document/applicati
> >on_note/group0/6a/82/83/37/61/69/4e/74/DM00497286/files/DM00497286.pd
> >f/jcr:content/translations/en.DM00497286.pdf
> >
> > Dave
> >
> > On 2/13/20 11:01 PM, 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
> > >
> > > On Thu, Feb 13, 2020, 5:46 AM Chris Albertson
> > >  > >
> > > wrote:
> > >> A sin and cos are 90 degrees apart.  All you should need to do is
> >
> > threshold
> >
> > >> the signal and you have A/B quadrature.Many ways to threshold
> > >> it but you want the one with least noise.
> > >>
> > >> A simple way to convert a sin wave to a square wave is to amplify
> > >> then
> >
> > clip
> >
> > >> it with diodes.   A comparator can also convert the signal.
> > >>
> > >> The point to remember is that sin/cos is quadrature and all that
> > >> is
> >
> > needed
> >
> > >> is some signal conditioning.
> > >>
> > >> On Tue, Feb 11, 2020 at 10:46 PM andrew beck
> > >> 
> > >>
> > >> wrote:
> > >>> Hi guys
> > >>>
> > >>> wondering if anyone has any ideas here.
> > >>>
> > >>> I have a heidanhain spindle motor that runs up to 1 rpm and
> > >>> has a
> >
> > 5v
> >
> > >>> sin cos encoder on it.  I am currently controlling the motor
> > >>> with a schiender vfd.  I am talking to the support engineers
> > >>> here in New
> >
> > Zealand
> >
> > >>> about buying a encoder card so I can get better low down torque.
> > >>>  If I
> > >>
> > >> run
> > >>
> > >>> the card in full encoder closed loop control in the vfd I can
> > >>> get 200 percent of the torque right down to 0 rpm for 30 seconds
> > >>> or so which is pretty useful.  I am currently just running the
> > >>> drive in Variable
> > >>
> > >> frequency
> > >>
> > >>> control which rapidly looses torque at low rpm.
> > >>>
> > >>> Anyway they have a bunch of cards I can use but don't have a
> > >>> encoder
> >
> > card
> >
> > >>> that is suitable for sin cos encoders.  I have no trouble
> > >>> changing the encoder but am not sure if I can get a source of
> > >>> encoders that spin up
> >
> > to
> >
> > >>> 10k rpm.

I am spinning a $20 1000 line encoder on the rear of the spindle motor. 
That is a diff output I'm making into rail to rail sq waves with rs485 
convertors. Wide open at the motor is still 4000 edges per turn. In high 
gear the spindle makes 3k revs, 750 more than OEM. The gear ratio in the 
head in high gear is a bit over 7.1 so at 3g indicated that 4000 edges = 
something in the 70k area, which is absolutely not a problem. This is 
with the A/B coming from the motor, but the index coming from an opto 
wheel under the drawbar bolt. gear ratios determined by counting A 
signals for 100 turns of the spindle, so I use 2 different scale values 
controlled by switches on the rim of the gearshift knob. That means 
everything is accurate to a very small fraction of 1%. And it works very 
well even at Pgains that totally hide any load induced slowdown, I am 
not aware of any overload until the currant limiter in Jon's (pico 
systems) pwm-servo which is what I am driving that motor with from a 126 
volt home brewed psu that needs at least a 20 amp supply breaker.  Its 
set for around 17 amps making the iron in the motor squeak, at close to 
double that motors nameplate FLA. Don't ask why I haven't stripped the 
plastic gears in the G0704's head, I don't know and they're now nearly 5 
years old. Since that driver is a true 4 quadrant driver, I took 
advantage of the knob switches to run the motor at about 35-40 rpms when 
neither switch is closed, so when the spindle is running but in the 
wrong gear, I can reach up and change gears quite safely as when neither 
switch is closed the

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

2020-02-14 Thread Chris Albertson 
Sorry.  Yes, a math error.A better estimate of the worst-case might to
20,000 RPM and 1000 pulses per rev.   That means 330,000 per second for
each channel.   But I bet close to 20,000 per second

A simple comparator with hysteresis would work well.   You really do need
to add hysteresis to deal with noise  Here is a good article:
http://www.ti.com/lit/ug/tidu020a/tidu020a.pdf

Hysteresis is a simple concept.  Every heater thermostat has this built
into it.  The "on-point" is lower than the "off-point"  otherwise the heat
would cycle to fast.

On Fri, Feb 14, 2020 at 8:25 AM andy pugh  wrote:

> On Fri, 14 Feb 2020 at 16:16, Chris Albertson 
> wrote:
>
> >
> > If there are even 100 pulses per revolution and the spindle runs at 100K
> > RPM then we are talking about 1K or 10 MHz.
> >
>
> 100,000 rpm is _very_ fast for a spindle. And even then you missed the 60
> in rpm / Hz conversion.
>
> --
> 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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-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] Open source CNC architecture

2020-02-14 Thread dave engvall 

John, et al:

The good thing about linuxcnc is that is can accommodate a wide range of 
user skill; from those who just want to make  chips to those that want 
to dig into the internals, to  those that can actually write internals. 
Ditto on the range of machines. Linuxcnc nee emc was tested on rather 
good sized machines at Boeing, GM and probably others. I think we have a 
few users that have machines in the 10 Kg region or more. I land 
somewhat in the middle with my big machine being 4200 Kg. On the other 
hand there are machines that one could pick up and walk out the door with.


Because linuxcnc is open source there are a variety of controls 
available, steppers as well as servo, including the ability to use 
rotary incremental encoders,  glass scales,  and resolvers.


Further history is here:

http://linuxcnc.org/docs/html/common/emc-history.html

The first system ran on a rather expensive VME bus system but things got 
cheaper when STG (Servo to Go ( only $888 )) offered an isa bus card.


Nuff blithering: back to getting something done. ;-)

Dave

On 2/14/20 12:59 AM, John Dammeyer wrote:

-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com]
Sent: February-13-20 9:51 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Open source CNC architecture

Yes, you do need a special PC.   This means a PC you use for Linux CNC and
not the one already on your desk.

I think that Chris made a lot of good points.  Since I'm upgrading my mill to 
CNC and using a dual boot PC and either LinuxCNC or MACH3 on WIN-XP/7 perhaps 
can add a slightly different view point.

When I designed the E-Leadscrew Electronic Lead Screw controller the feedback 
from the non-CNC people was that they wanted something more than just 
electronic gearing (now commonly also called an ELS) but not something as 
extensive as full CNC.  So what exactly does that mean?  For that matter what 
does open source mean?  Those are both really good questions.

I'll pass on the lathe description for now and address a milling machine.   
I've managed to get along for a number of years with a DRO and power feed on 
the X axis.  Adding a 5C collect spin indexer and a small rotary table indexed 
by my ELS I've found I have been able to create quite a few different things 
without CNC.  So why has it taken so long to convert to CNC when my JGRO based 
CNC router ran MACH3 from the start.  It's not like I'm afraid of it.

Quite simply for many milling (or lathe projects) that are one-of, the precise 
feedback of a DRO on all three axis and power feed relieves the boredom to a 
certain extent.  But what would improve any mill is power feed on all three 
axis along with the DRO.  And the power feed, if augmented by begin/end 
positions would allow all sorts of linear mill operations including peck 
drilling and, with spindle feedback, like threading on a lathe, power tapping.  
No G-Code based CNC code required.  And unfortunately no I,J motion for arcs.  
Although even those kinds of motions could be set up just as easy as 
co-ordinated motion like the tapering I have on my ELS.

So now we're back to the question that Chris raised about a PC or a dedicated 
embedded controller and relates to my first question above.  LinuxCNC and the 
PC worked because it used the parallel port, or if an add on card was added 
closed loop servo control was possible.  But at some point we cross the line 
from a PC running the CNC software to the PC serving as the interface to custom 
hardware with FPGAs and/or processors dealing with the motion control.  So the 
line has become blurry.

The costs, and they are always important, break down to the high powered 
trajectory planner and user feedback,  the actual motion signals and finally 
the electrical interface often referred to as a Break Out Board.Some of the 
ancillary hardware combines the BoB and the motion control into one package.  
Other solutions use Ethernet to something that creates the motion signals 
coupled to a BoB.  And above both is the trajectory planning/control and user 
interface.

But unless you use a parallel port that is part of the PC the reality is the 
system has already been broken into a CNC controller of some sort that costs 
between $100 and $300.  If you decide to use a MESA Ethernet solution with 
terminal strips and stepping engines etc. there is nothing in the rule book 
that says that the user interface and trajectory planner has to be LinuxCNC.

And on the other side if you are using LinuxCNC if the HAL file loads an 
equivalent to:
loadrt hm2_eth board_ip="192.168.1.121" config=" num_encoders=0 num_pwmgens=0 
num_stepgens=5"
there's absolutely no reason the device with the above IP address has to be a 
MESA product.

It could, in fact, just as easily look like the $300 CNC controllers with LCD 
displays, buttons terminal strips etc. to connect to Servo or step motors etc.  
And that $300 CNC controller might just have the equivalent

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

2020-02-14 Thread andy pugh 
On Fri, 14 Feb 2020 at 16:16, Chris Albertson 
wrote:

>
> If there are even 100 pulses per revolution and the spindle runs at 100K
> RPM then we are talking about 1K or 10 MHz.
>

100,000 rpm is _very_ fast for a spindle. And even then you missed the 60
in rpm / Hz conversion.

-- 
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] trying to connect a encoder from cnc spindle motor to schiender vfd

2020-02-14 Thread Chris Albertson 
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-

If there are even 100 pulses per revolution and the spindle runs at 100K
RPM then we are talking about 1K or 10 MHz.   At that point I start
thinking about hardware quadrature decoding rather than software or in the
Linux CNC world they use FPGA chips.

But without understanding the signal it is way to early to even think about
a design solution.Let's see what's on all the wires first.

On Fri, Feb 14, 2020 at 7:29 AM dave engvall  wrote:

> a bit overdone for your app but this should give you an idea. page down
> to fig 16.
>
>
> https://www.st.com/content/ccc/resource/technical/document/application_note/group0/6a/82/83/37/61/69/4e/74/DM00497286/files/DM00497286.pdf/jcr:content/translations/en.DM00497286.pdf
>
> Dave
>
> On 2/13/20 11:01 PM, 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
> >
> > On Thu, Feb 13, 2020, 5:46 AM Chris Albertson  >
> > wrote:
> >
> >> A sin and cos are 90 degrees apart.  All you should need to do is
> threshold
> >> the signal and you have A/B quadrature.Many ways to threshold it but
> >> you want the one with least noise.
> >>
> >> A simple way to convert a sin wave to a square wave is to amplify then
> clip
> >> it with diodes.   A comparator can also convert the signal.
> >>
> >> The point to remember is that sin/cos is quadrature and all that is
> needed
> >> is some signal conditioning.
> >>
> >> On Tue, Feb 11, 2020 at 10:46 PM andrew beck 
> >> wrote:
> >>
> >>> Hi guys
> >>>
> >>> wondering if anyone has any ideas here.
> >>>
> >>> I have a heidanhain spindle motor that runs up to 1 rpm and has a
> 5v
> >>> sin cos encoder on it.  I am currently controlling the motor with a
> >>> schiender vfd.  I am talking to the support engineers here in New
> Zealand
> >>> about buying a encoder card so I can get better low down torque.  If I
> >> run
> >>> the card in full encoder closed loop control in the vfd I can get 200
> >>> percent of the torque right down to 0 rpm for 30 seconds or so which is
> >>> pretty useful.  I am currently just running the drive in Variable
> >> frequency
> >>> control which rapidly looses torque at low rpm.
> >>>
> >>> Anyway they have a bunch of cards I can use but don't have a encoder
> card
> >>> that is suitable for sin cos encoders.  I have no trouble changing the
> >>> encoder but am not sure if I can get a source of encoders that spin up
> to
> >>> 10k rpm.
> >>>
> >>> Anyone have any suggestions?
> >>>
> >>> regards
> >>>
> >>> Andrew
> >>>
> >>> ___
> >>> Emc-users mailing list
> >>> Emc-users@lists.sourceforge.net
> >>> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>>
> >>
> >> --
> >>
> >> Chris Albertson
> >> Redondo Beach, California
> >>
> >> ___
> >> Emc-users mailing list
> >> Emc-users@lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>
> > ___
> > Emc-users mailing list
> > 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] trying to connect a encoder from cnc spindle motor to schiender vfd

2020-02-14 Thread andy pugh 
On Fri, 14 Feb 2020 at 15:29, dave engvall  wrote:

>
>
> https://www.st.com/content/ccc/resource/technical/document/application_note/group0/6a/82/83/37/61/69/4e/74/DM00497286/files/DM00497286.pdf/jcr:content/translations/en.DM00497286.pdf


Resolvers are a different (and slightly harder) problem as they are AC
output.

The answer almost certainly is an EXE box.
https://www.ebay.com/itm/303373292470
For example.

But an Arduino might be a fun project to achieve the same thing.
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?ResolverToQuadratureConverter
Is likely to get you close. You do not need any of the excitation signal
generation code or hardware, though)

-- 
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] trying to connect a encoder from cnc spindle motor to schiender vfd

2020-02-14 Thread dave engvall 
a bit overdone for your app but this should give you an idea. page down 
to fig 16.


https://www.st.com/content/ccc/resource/technical/document/application_note/group0/6a/82/83/37/61/69/4e/74/DM00497286/files/DM00497286.pdf/jcr:content/translations/en.DM00497286.pdf

Dave

On 2/13/20 11:01 PM, 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

On Thu, Feb 13, 2020, 5:46 AM Chris Albertson 
wrote:


A sin and cos are 90 degrees apart.  All you should need to do is threshold
the signal and you have A/B quadrature.Many ways to threshold it but
you want the one with least noise.

A simple way to convert a sin wave to a square wave is to amplify then clip
it with diodes.   A comparator can also convert the signal.

The point to remember is that sin/cos is quadrature and all that is needed
is some signal conditioning.

On Tue, Feb 11, 2020 at 10:46 PM andrew beck 
wrote:


Hi guys

wondering if anyone has any ideas here.

I have a heidanhain spindle motor that runs up to 1 rpm and has a 5v
sin cos encoder on it.  I am currently controlling the motor with a
schiender vfd.  I am talking to the support engineers here in New Zealand
about buying a encoder card so I can get better low down torque.  If I

run

the card in full encoder closed loop control in the vfd I can get 200
percent of the torque right down to 0 rpm for 30 seconds or so which is
pretty useful.  I am currently just running the drive in Variable

frequency

control which rapidly looses torque at low rpm.

Anyway they have a bunch of cards I can use but don't have a encoder card
that is suitable for sin cos encoders.  I have no trouble changing the
encoder but am not sure if I can get a source of encoders that spin up to
10k rpm.

Anyone have any suggestions?

regards

Andrew

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--

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Redondo Beach, California

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

2020-02-14 Thread Gene Heskett 
On Friday 14 February 2020 07:29:53 Gene Heskett wrote:

> 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 -
>
> time is left to right if clockwise, or right to left if
> counterclockwise. poor ascii image of oscilloscope trace sorry.
>
> From this train of pulses coming out of the encoder the edges per time
> unit can be very accurately turned into an rpm scale to be displayed.
>
> Also the direction its moving is available at the output, freshly
> determined at the instant of any change in status of these two
> signals.
>
> Now add a 3rd signal, call it I for index, which has only a narrow
> pulse that probably is identical to just one of the above but is only
> sent by the encoder once per revolution.  This tells the decoder,
> called an encoder for some reason I don't control, that it has
> moved|turned one full turn.  linear scales may or may not have this
> last signal but rotary encoders nearly always do.  If present, this
> allows a scale to be measured and established with which you can the
> measure how far something has moved down to sub-micron accuracy.
> Applied to a spindle, it allows linuxcnc to know exactly where in its
> rotation the spindle is and that in turn allows linuxcnc to drive a
> tap into a predrilled hole, and back out at the exact pitch of the
> tap. We call that rigid tapping and taps last a lng time time
> because they are not being bent or otherwise stressed by hand tapping.
>
> There are conditions in driveing a stepper motor faster than it can
> track that same format of driving signal to the coils of a stepper,
> and keeping that slow enough the stepper can keep up becomes that
> axis's speed limit.  But thats a whole different critter and subject.
>
> This type of encoder signal never skips a count even after millions of
> direction changes.  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.

correction here, that should say "the machines motor drivers, which for 
stepper motors is normally done by step and step direction signals."

> I hope this helps explain it.  Introducing the element of time often
> causes some confusion to the idea of drawing a vertical line thru the
> above accii drawing to mark the instant of time to what happens next.
>
>
> Cheers, Gene Heskett


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

2020-02-14 Thread Gene Heskett 
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 -

time is left to right if clockwise, or right to left if counterclockwise.
poor ascii image of oscilloscope trace sorry.

>From this train of pulses coming out of the encoder the edges per time 
unit can be very accurately turned into an rpm scale to be displayed.

Also the direction its moving is available at the output, freshly 
determined at the instant of any change in status of these two signals.

Now add a 3rd signal, call it I for index, which has only a narrow pulse 
that probably is identical to just one of the above but is only sent by 
the encoder once per revolution.  This tells the decoder, called an 
encoder for some reason I don't control, that it has moved|turned one 
full turn.  linear scales may or may not have this last signal but 
rotary encoders nearly always do.  If present, this allows a scale to be 
measured and established with which you can the measure how far 
something has moved down to sub-micron accuracy. Applied to a spindle, 
it allows linuxcnc to know exactly where in its rotation the spindle is 
and that in turn allows linuxcnc to drive a tap into a predrilled hole, 
and back out at the exact pitch of the tap. We call that rigid tapping 
and taps last a lng time time because they are not being bent or 
otherwise stressed by hand tapping.

There are conditions in driveing a stepper motor faster than it can track 
that same format of driving signal to the coils of a stepper, and 
keeping that slow enough the stepper can keep up becomes that axis's 
speed limit.  But thats a whole different critter and subject.

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

I hope this helps explain it.  Introducing the element of time often 
causes some confusion to the idea of drawing a vertical line thru the 
above accii drawing to mark the instant of time to what happens next. 
 

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

2020-02-14 Thread andrew beck 
OK I'll try track down the data sheet.  Failing that I'll borrow a
oscilloscope and have a play.  I'll post back here tomorrow

Thanks chris

Regards

Andrew

On Fri, Feb 14, 2020, 8:51 PM Chris Albertson 
wrote:

> First step is to understand (1) what you have and (2) what you need.
>
> So,  If the spindle revolves one time, How many cycles of the sin wave do
> you see?  What is the amplitude of the sine wave (in volts peak to peak)?
> Does the amplitude change with the spindle speed?You need to either
> read this information from the encoder's data sheet or measure it
>
>
> I assume you need a 5-volt square wave quadrature signal.   A potential
> problem with square wave converters is noise.   But lets first see what the
> sin wave signal looks like.
>
> On Thu, Feb 13, 2020 at 11:03 PM 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
> >
> > On Thu, Feb 13, 2020, 5:46 AM Chris Albertson  >
> > wrote:
> >
> > > A sin and cos are 90 degrees apart.  All you should need to do is
> > threshold
> > > the signal and you have A/B quadrature.Many ways to threshold it
> but
> > > you want the one with least noise.
> > >
> > > A simple way to convert a sin wave to a square wave is to amplify then
> > clip
> > > it with diodes.   A comparator can also convert the signal.
> > >
> > > The point to remember is that sin/cos is quadrature and all that is
> > needed
> > > is some signal conditioning.
> > >
> > > On Tue, Feb 11, 2020 at 10:46 PM andrew beck  >
> > > wrote:
> > >
> > > > Hi guys
> > > >
> > > > wondering if anyone has any ideas here.
> > > >
> > > > I have a heidanhain spindle motor that runs up to 1 rpm and has a
> > 5v
> > > > sin cos encoder on it.  I am currently controlling the motor with a
> > > > schiender vfd.  I am talking to the support engineers here in New
> > Zealand
> > > > about buying a encoder card so I can get better low down torque.  If
> I
> > > run
> > > > the card in full encoder closed loop control in the vfd I can get 200
> > > > percent of the torque right down to 0 rpm for 30 seconds or so which
> is
> > > > pretty useful.  I am currently just running the drive in Variable
> > > frequency
> > > > control which rapidly looses torque at low rpm.
> > > >
> > > > Anyway they have a bunch of cards I can use but don't have a encoder
> > card
> > > > that is suitable for sin cos encoders.  I have no trouble changing
> the
> > > > encoder but am not sure if I can get a source of encoders that spin
> up
> > to
> > > > 10k rpm.
> > > >
> > > > Anyone have any suggestions?
> > > >
> > > > regards
> > > >
> > > > Andrew
> > > >
> > > > ___
> > > > Emc-users mailing list
> > > > Emc-users@lists.sourceforge.net
> > > > https://lists.sourceforge.net/lists/listinfo/emc-users
> > > >
> > >
> > >
> > > --
> > >
> > > Chris Albertson
> > > Redondo Beach, California
> > >
> > > ___
> > > Emc-users mailing list
> > > 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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>

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Re: [Emc-users] Open source CNC architecture

2020-02-14 Thread John Dammeyer 
> -Original Message-
> From: Chris Albertson [mailto:albertson.ch...@gmail.com]
> Sent: February-13-20 9:51 AM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Open source CNC architecture
> 
> Yes, you do need a special PC.   This means a PC you use for Linux CNC and
> not the one already on your desk.

I think that Chris made a lot of good points.  Since I'm upgrading my mill to 
CNC and using a dual boot PC and either LinuxCNC or MACH3 on WIN-XP/7 perhaps 
can add a slightly different view point. 

When I designed the E-Leadscrew Electronic Lead Screw controller the feedback 
from the non-CNC people was that they wanted something more than just 
electronic gearing (now commonly also called an ELS) but not something as 
extensive as full CNC.  So what exactly does that mean?  For that matter what 
does open source mean?  Those are both really good questions.

I'll pass on the lathe description for now and address a milling machine.   
I've managed to get along for a number of years with a DRO and power feed on 
the X axis.  Adding a 5C collect spin indexer and a small rotary table indexed 
by my ELS I've found I have been able to create quite a few different things 
without CNC.  So why has it taken so long to convert to CNC when my JGRO based 
CNC router ran MACH3 from the start.  It's not like I'm afraid of it.

Quite simply for many milling (or lathe projects) that are one-of, the precise 
feedback of a DRO on all three axis and power feed relieves the boredom to a 
certain extent.  But what would improve any mill is power feed on all three 
axis along with the DRO.  And the power feed, if augmented by begin/end 
positions would allow all sorts of linear mill operations including peck 
drilling and, with spindle feedback, like threading on a lathe, power tapping.  
No G-Code based CNC code required.  And unfortunately no I,J motion for arcs.  
Although even those kinds of motions could be set up just as easy as 
co-ordinated motion like the tapering I have on my ELS.

So now we're back to the question that Chris raised about a PC or a dedicated 
embedded controller and relates to my first question above.  LinuxCNC and the 
PC worked because it used the parallel port, or if an add on card was added 
closed loop servo control was possible.  But at some point we cross the line 
from a PC running the CNC software to the PC serving as the interface to custom 
hardware with FPGAs and/or processors dealing with the motion control.  So the 
line has become blurry.

The costs, and they are always important, break down to the high powered 
trajectory planner and user feedback,  the actual motion signals and finally 
the electrical interface often referred to as a Break Out Board.Some of the 
ancillary hardware combines the BoB and the motion control into one package.  
Other solutions use Ethernet to something that creates the motion signals 
coupled to a BoB.  And above both is the trajectory planning/control and user 
interface.

But unless you use a parallel port that is part of the PC the reality is the 
system has already been broken into a CNC controller of some sort that costs 
between $100 and $300.  If you decide to use a MESA Ethernet solution with 
terminal strips and stepping engines etc. there is nothing in the rule book 
that says that the user interface and trajectory planner has to be LinuxCNC.  

And on the other side if you are using LinuxCNC if the HAL file loads an 
equivalent to:
loadrt hm2_eth board_ip="192.168.1.121" config=" num_encoders=0 num_pwmgens=0 
num_stepgens=5"
there's absolutely no reason the device with the above IP address has to be a 
MESA product.

It could, in fact, just as easily look like the $300 CNC controllers with LCD 
displays, buttons terminal strips etc. to connect to Servo or step motors etc.  
And that $300 CNC controller might just have the equivalent to my ELS user 
interface that lets you operate this mill as a manual mill with DRO, power feed 
and some pre-programmed motion.   So without the PC and LinuxCNC it's a 
sophisticated manual mill.  Power up the PC or tablet or whatever talks 
Ethernet and LinuxCNC (or whatever user interface + trajectory planner) and you 
have full CNC.

And that's where the second question perhaps might be answered.  What exactly 
is open source?  In a way it's LinuxCNC but only a few guru's really understand 
what is happening under the covers because it's so incredibly powerful.The 
MESA cards can be modified since much of the FPGA information is published.  
But unlike MACH3 where a simple checkbox changes the spindle step pin into a 
pwm pin the FPGA world requires knowledge of the entire FPGA programming 
environment and it can't just be changed with a check box on a set up dialog 
box.

And in the LinuxCNC world one has to be very careful when asking a question in 
fear of being chastised for not doing their own research and memorizing all the 
command line options of a 1970's based