Re: [Emc-users] Rotary Axis Designs

[Rob Jansen]

The same procedure as Belli Button suggest is indeed standard. Two (half 
height) gears mounted on top of each other and interlocking the the 
driving gear to remove the play on the gearing.
Easy for standard gears or trapezoid and ball screw axis (two nuts on 
one axis) but a bit more complex for worm gears.

Most rotary tables (like the vertex one: 
http://hamilton-tool-supply.amazonwebstore.com/B000HRY444/M/B000HRY444.htm) 
have a little pin located next to the hand wheel. That pin moves the 
worm in an eccentric mount so you can move the worm closer to the bronze 
wheel - I found you can remove the play by moving this.
But ... the problem is that the bronze wheel may not be fully centric 
mounted, resulting in a difference of the distance between bronze wheel 
and worm drive, resulting in too much friction or too much play. To fix 
this you'll have to reposition the bronze wheel.

I guess the more professional and expensive ones will be using some way 
to center the wheel (using a conus) but on the Vertex rotary table there 
is a bit of play on the mount of the wheel on the rotating table. Still 
I managed to reduce the play on my vertex 4th axis to an acceptable 
level - but then I am not milling fine pitched large gears with it ...

Regards,

Rob

Belli Button wrote:
> It can be done with the Bonfig style worm gearboxes.  What you need to do is 
> strip the gearbox, remove the bronze wheel and cut it in 'half' (slice?) 
> with a wire cutter.  Then mill three slots concentric to the centre on one 
> half and drill and tap three corresponding holes on the other half.  When 
> you reassemble the gearbox, slide the one half relative to the other to take 
> up the backlash.  This seems to work really well but does require a bit of 
> engineering.  We have built some fairly large '4th Axes' like this for not a 
> great deal of money.
>
> Clear as mud?
>   

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Re: [Emc-users] Servo Control

[Kirk Wallace]

On Tue, 2009-05-26 at 12:09 +1000, Jake Anderson wrote:
> perhaps take a look at what the hexapod guys are doing, They seem to use 
> hobby servos with EMC.
> 
... snip

Just shooting in the dark...

Another option might be to use the R/C servo as a motor and gearbox,
then rig up a separate encoder.

When I think of R/C servos, Sparkfun comes to mind for some reason:
http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=servo&x=18&y=12&search_section=products
 
(Short URL preview, link) http://preview.alturl.com/e8c7
http://alturl.com/e8c7 

Good luck.
-- 
Kirk Wallace
http://www.wallacecompany.com/machine_shop/
http://www.wallacecompany.com/E45/index.html
California, USA


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Re: [Emc-users] Servo Control

[Jake Anderson]

perhaps take a look at what the hexapod guys are doing, They seem to use hobby 
servos with EMC.



Anders Wallin wrote:
> R/C Servos take a digital pulse input at around 50 (or 100?) Hz.
> The width of the pulse determines the position of the servo.
> A width of 1.5 ms is the central position, and 1.0 ms is full left (for 
> example), while 2.0 ms is full right.
>
> if you have digital I/O connected to EMC (parallel port or a pci-card) 
> and a machine that can run with a base_period of 25us that would mean 
> around 40 base_period's for the full range of motion of the servo.
> Do you need more resolution? Some machines may be able to run with a 
> shorter base_period.
>
> There might be an existing PWM HAL component you can use to produce this 
> output, but it's not hard to code your own if you need to.
>
> Anders
>
>
>   
>> Hi,
>>
>> I am planning to build a robot arm which holds a driller. (it means 6dof 
>> afaik)
>>
>> Is there a way to write a configuration to control 3 std. R/C servos 
>> directly? Where do I have to look? The way which seems easy to me is 
>> burning a PIC interface  prog which takes parport information and 
>> emulates stepper motors. Is there a direct way? As you can imagine it 
>> will reduce operation speed of machine too much.
>>
>> Thanks
>> 
>
>
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Re: [Emc-users] Rotary Axis Designs

[Dave Engvall]

That is standard antibacklash technology ... the B-17 intervalometer  
had several sets of them with springs between the two gears to  
maintain loading on
the gears.

Nice tight worm gear sets are made by lapping the sets.  see  
"Foundations of Mechanical Accuracy" by Wayne R Moore, pg 221-228.

HTH

Dave
On May 25, 2009, at 1:31 PM, Belli Button wrote:

> It can be done with the Bonfig style worm gearboxes.  What you need  
> to do is
> strip the gearbox, remove the bronze wheel and cut it in  
> 'half' (slice?)
> with a wire cutter.  Then mill three slots concentric to the centre  
> on one
> half and drill and tap three corresponding holes on the other  
> half.  When
> you reassemble the gearbox, slide the one half relative to the  
> other to take
> up the backlash.  This seems to work really well but does require a  
> bit of
> engineering.  We have built some fairly large '4th Axes' like this  
> for not a
> great deal of money.
>
> Clear as mud?
>
>
> - Original Message -
> From: "Kirk Wallace" 
> To: "Enhanced Machine Controller (EMC)"  us...@lists.sourceforge.net>
> Sent: Monday, May 25, 2009 7:00 PM
> Subject: Re: [Emc-users] Rotary Axis Designs
>
>
>> On Mon, 2009-05-25 at 18:12 +0200, Roland Jollivet wrote:
>>> What about using an AC motor reduction drive. They're pretty  
>>> robust but
>>> I'm
>>> not sure about the backlash. Usually easy to find as surplus.
>>> Something like this;
>>> http://www.bonfiglioli.com/vfpres_uk.html
>>>
>>> Replace the AC motor with a stepper.
>>>
>>>
>>> Regards
>>> Roland
>>
>> If the backlash on the worm drive can be adjusted, and I can find one
>> cheap enough, I can't see why it wouldn't work. It would be fun to  
>> make
>> one of each design, but that's not too likely to happen.  
>> Sometimes, I'll
>> visit a friend or a dumpster and fate will decide what I do. It sure
>> would be nice to have a little less fate in my life (or not).
>>
>> -- 
>> Kirk Wallace
>> http://www.wallacecompany.com/machine_shop/
>> http://www.wallacecompany.com/E45/index.html
>> California, USA
>>
>>
>> - 
>> -
>> Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT
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>> professionals.
>> Meet
>> the minds behind Google Creative Lab, Visual Complexity,  
>> Processing, &
>> iPhoneDevCamp asthey present alongside digital heavyweights like  
>> Barbarian
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>
>
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Re: [Emc-users] Rotary Axis Designs

[Belli Button]

It can be done with the Bonfig style worm gearboxes.  What you need to do is 
strip the gearbox, remove the bronze wheel and cut it in 'half' (slice?) 
with a wire cutter.  Then mill three slots concentric to the centre on one 
half and drill and tap three corresponding holes on the other half.  When 
you reassemble the gearbox, slide the one half relative to the other to take 
up the backlash.  This seems to work really well but does require a bit of 
engineering.  We have built some fairly large '4th Axes' like this for not a 
great deal of money.

Clear as mud?


- Original Message - 
From: "Kirk Wallace" 
To: "Enhanced Machine Controller (EMC)" 
Sent: Monday, May 25, 2009 7:00 PM
Subject: Re: [Emc-users] Rotary Axis Designs


> On Mon, 2009-05-25 at 18:12 +0200, Roland Jollivet wrote:
>> What about using an AC motor reduction drive. They're pretty robust but 
>> I'm
>> not sure about the backlash. Usually easy to find as surplus.
>> Something like this;
>> http://www.bonfiglioli.com/vfpres_uk.html
>>
>> Replace the AC motor with a stepper.
>>
>>
>> Regards
>> Roland
>
> If the backlash on the worm drive can be adjusted, and I can find one
> cheap enough, I can't see why it wouldn't work. It would be fun to make
> one of each design, but that's not too likely to happen. Sometimes, I'll
> visit a friend or a dumpster and fate will decide what I do. It sure
> would be nice to have a little less fate in my life (or not).
>
> -- 
> Kirk Wallace
> http://www.wallacecompany.com/machine_shop/
> http://www.wallacecompany.com/E45/index.html
> California, USA
>
>
> --
> Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT
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> Meet
> the minds behind Google Creative Lab, Visual Complexity, Processing, &
> iPhoneDevCamp asthey present alongside digital heavyweights like Barbarian
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Re: [Emc-users] [Fwd: Heiz CNC - emc configuration] 5th axis

[Péter Bocska]

Hello,
no real reason yet, I was just wandering how it would be possible. I am
still learning the cnc machining, and I see here on this list wonderful
codes and ideas how to make more complex parts like gears, and I see some
very nice videos on youtube about 5 axis machines. So I thought maybe I
could try to make the 5th axis, first only in principle. The mechanical
sollution could be like on this video:
http://www.youtube.com/watch?v=DjPCEpZybXs
You are right, the software part would be tough, but it still woths to
consider, I will look around and search on the net.

Best regards,
Peter



2009/5/25 Greg Michalski 

> > -Original Message-
> > From: Robert von Knobloch [mailto:b...@engelking.de]
> > Subject: [Emc-users] [Fwd: Heiz CNC - emc configuration] 5th axis
> >
> > Peter wrote:
> >
> > Hello Robert,
> >
> > Have you ever thought about making the 5th axis to your Heiz machine?
> The
> > Heiz controller is capable for 4 axis, and with another LPT port and
> > controller and step motor would it be possible to drive the 5th axis?
> What
> > do you think?
> >
> > Best Regards,
> > Peter
> >
> >
> > I can see no reason why not, except maybe the difficulty of generating
> > gcode from cad to drive it.
> > EMC can handle up to 6 axes.
> > I do not have a reason for a 5th. axis on my machine.
> > What do you want to use it for ?
> >
> > Best regards,
> > Robert
>
> I think you meant to say EMC could handle 9 axes. (XYZABCUVW)  :-)
>
> Greg
> www.distinctperspectives.com
>
>
>
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Re: [Emc-users] Rotary Axis Designs

[Rainer Schmidt]

When you can manage to keep the axis running in one direction the
backlash is of no factor. I like the dremel idea. I made a very simple
attachment for the Dremel and my Southbend. Beats the $1000+ for the
grinding attachment for thw three times I used it. However, I was
careful to keep that grit of the machine.
R

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Re: [Emc-users] Rotary Axis Designs

[Kirk Wallace]

On Mon, 2009-05-25 at 18:12 +0200, Roland Jollivet wrote:
> What about using an AC motor reduction drive. They're pretty robust but I'm
> not sure about the backlash. Usually easy to find as surplus.
> Something like this;
> http://www.bonfiglioli.com/vfpres_uk.html
> 
> Replace the AC motor with a stepper.
> 
> 
> Regards
> Roland

If the backlash on the worm drive can be adjusted, and I can find one
cheap enough, I can't see why it wouldn't work. It would be fun to make
one of each design, but that's not too likely to happen. Sometimes, I'll
visit a friend or a dumpster and fate will decide what I do. It sure
would be nice to have a little less fate in my life (or not).

-- 
Kirk Wallace
http://www.wallacecompany.com/machine_shop/
http://www.wallacecompany.com/E45/index.html
California, USA


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Re: [Emc-users] Rotary Axis Designs

[Roland Jollivet]

What about using an AC motor reduction drive. They're pretty robust but I'm
not sure about the backlash. Usually easy to find as surplus.
Something like this;
http://www.bonfiglioli.com/vfpres_uk.html

Replace the AC motor with a stepper.


Regards
Roland



2009/5/25 Kirk Wallace 

> I need to start to think about making or getting a rotary axis. The
> first thing that comes to mind is to adapt a servo and encoder to one of
> these:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260343949073
>
> What other options should I consider, maybe start from scratch, if so
> what type of drive?
> --
> Kirk Wallace
> http://www.wallacecompany.com/machine_shop/
> http://www.wallacecompany.com/E45/index.html
> California, USA
>
>
>
> --
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Re: [Emc-users] Servo Control

[Peter C. Wallace]

On Mon, 25 May 2009, Anders Wallin wrote:

> Date: Mon, 25 May 2009 18:25:32 +0300
> From: Anders Wallin 
> Reply-To: "Enhanced Machine Controller (EMC)"
> 
> To: "Enhanced Machine Controller (EMC)" 
> Subject: Re: [Emc-users] Servo Control
> 
>
> R/C Servos take a digital pulse input at around 50 (or 100?) Hz.
> The width of the pulse determines the position of the servo.
> A width of 1.5 ms is the central position, and 1.0 ms is full left (for
> example), while 2.0 ms is full right.
>
> if you have digital I/O connected to EMC (parallel port or a pci-card)
> and a machine that can run with a base_period of 25us that would mean
> around 40 base_period's for the full range of motion of the servo.
> Do you need more resolution? Some machines may be able to run with a
> shorter base_period.
>
> There might be an existing PWM HAL component you can use to produce this
> output, but it's not hard to code your own if you need to.
>
> Anders


Oops Anders is right on resolution I'd forgotton that RC servos use such a 
narrow range of pulse widths


Peter Wallace
Mesa Electronics

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Re: [Emc-users] Servo Control

[Peter C. Wallace]

On Mon, 25 May 2009, Emre Ersin wrote:

> Date: Mon, 25 May 2009 16:49:05 +0300
> From: Emre Ersin 
> Reply-To: "Enhanced Machine Controller (EMC)"
> 
> To: "Enhanced Machine Controller (EMC)" 
> Subject: [Emc-users] Servo Control
> 
> Hi,
>
> I am planning to build a robot arm which holds a driller. (it means 6dof
> afaik)
>
> Is there a way to write a configuration to control 3 std. R/C servos
> directly? Where do I have to look? The way which seems easy to me is
> burning a PIC interface  prog which takes parport information and
> emulates stepper motors. Is there a direct way? As you can imagine it
> will reduce operation speed of machine too much.
>
> Thanks
> -- 
>
> Emre Ersin
>

external hardware should not be needed, EMCs software PWM generation should 
work fine for RC-servos, 10 bit resolution should be possible at 50 Hz with a 
PC that has decent latency.

Maybe a HAL expert could suggest how to connect absolute position output 
devices like R/C servos...

Peter Wallace
Mesa Electronics

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Re: [Emc-users] Servo Control

[Anders Wallin]

R/C Servos take a digital pulse input at around 50 (or 100?) Hz.
The width of the pulse determines the position of the servo.
A width of 1.5 ms is the central position, and 1.0 ms is full left (for 
example), while 2.0 ms is full right.

if you have digital I/O connected to EMC (parallel port or a pci-card) 
and a machine that can run with a base_period of 25us that would mean 
around 40 base_period's for the full range of motion of the servo.
Do you need more resolution? Some machines may be able to run with a 
shorter base_period.

There might be an existing PWM HAL component you can use to produce this 
output, but it's not hard to code your own if you need to.

Anders


> Hi,
> 
> I am planning to build a robot arm which holds a driller. (it means 6dof 
> afaik)
> 
> Is there a way to write a configuration to control 3 std. R/C servos 
> directly? Where do I have to look? The way which seems easy to me is 
> burning a PIC interface  prog which takes parport information and 
> emulates stepper motors. Is there a direct way? As you can imagine it 
> will reduce operation speed of machine too much.
> 
> Thanks


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Re: [Emc-users] Rotary Axis Designs

[Gene Heskett]

On Monday 25 May 2009, Rainer Schmidt wrote:
>Haha.. The Belt Stiffness fools many. It's a PU timing belt which is
>steel loaded. I tensioned it to 160lbs and the think sounds like a
>guitar string. There is NO flex whatsoever. If there would be... most
>cars would sink their valves into the cylinders more often than not.
>The ratio is 1:3 and the stepper has 10 steps micro stepping. So I get
>2000 steps per revolution times three. So I get 360/6000 degree
>resolution which I could reproduce. If you would use a servo then you
>can easily tripple that resolution with the right encoder. I chose a
>stepper there because I wanted the high holding torque for unbalanced
>work. Did I mention that it is FAST.
>
>I also hae a sherline table on my Taig mill. And that's where it
>belongs. I mill pen's with it and for that it's nice and very precise.
>However, it does wear as all the stuff does which is not designed for
>CNC kinda moves (which means a LOT of moves). And for the price of it
>I milled my monster 4th. The timkin bearings are sitting in those 3
>Inch AL blocks 8))). Derived from the shaft all measurements became
>slightly beefy lol.
>
>I also milled a groove into the bottom of the head and the tailstock
>so alignment is easy. The biggest challenge was to bore that hole for
>the MT3 sleeve. Compared to the tailstock I must say that the sherline
>tailstock resembles a toothpick.
>
>If you wish to mill tiny stuff and not to often then go for the
>sherline table combo. If you need a quick turning cnc solution then
>build one. I took a look at all sorts of tables and the ones suitable
>would have been precision US or European made rotary tables which
>would have cost me several thousand dollars and that for no other
>reason but backlash. Na building one or having one build is
>probably the best way to go as there are no affordable CNC tables.
>
>Yesterday I used it to cut a thread into a larger hole in a wood
>block. No way to do that with the slow turning regular tables. it has
>to go 'swish swish swish' and not scrp, screechh,
>squl. haha.
>
>Have a good memorial day and recall what others did for your
>particular country so they did not do it in vain.
>Rainer

I looked at your 'rotary table' and must say I'm impressed.  Unforch, it would 
take up the whole x table of my expanded micromill.  So ATM, when I need a 
4th, I have a $100 4" grizzly I put a 425 oz stepper on, and it can make 4 to 
7 hundred degrees a minute depending on the mood its in.  Backlash is highly 
variable, and this unit is so cheap it doesn't even have a socket for a 
center.  I also had to do some finish machining to take the wobble out, the 
table did not sit tightly enough against the base as shipped.  Using edm, I 
put some holes in a 10" carbide saw blade that was way too hard for 
conventional drilling a few weeks ago so I could fasten it to this table, 
rigged a dremel with a diamond wheel off the regular head, and did a decent 
job of sharpening that dull saw blade.  The thing didn't seem to have much if 
any cyclic errors, either in the worm or in the bullgear, at least in 
comparison to the spacing of the teeth on the blade, a Freud made, chrome 
plated avanti.  Sweet blade, but a few thousand feet of cuts in cherry will 
sour any blade eventually.

I don't have any provision to lock the table, but make sure it always attacks 
the work rather than backing into it.  I haven't had it miss cut yet because 
of that, at least not that I've seen in the work.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
The NRA is offering FREE Associate memberships to anyone who wants them.


What, after all, is a halo?  It's only one more thing to keep clean.
-- Christopher Fry


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Re: [Emc-users] [OT] Gear Tooth Form

[Steve Stallings]

 You can snag a copy of geargen from here:

http://www.metalworking.com/shareware.html

Sorry, but I never found the source code.

Cheers,
Steve Stallings


> -Original Message-
> From: Andre B. [mailto:ablanch...@wildblue.net] 
> Sent: Sunday, May 24, 2009 5:44 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] [OT] Gear Tooth Form
> 
> Have you looked at geargen11 it is an old DOS program should 
> still be available someplace.
> 
> 
> At 09:34 AM 5/20/2009, you wrote:
> >On Wed, 2009-05-20 at 04:44 -0500, Ray Henry wrote:
> >... snip
> > > I dropped in on the folk at Synergy the other evening and 
> they demoed
> > > gear design for me.  Answer a few questions like number 
> of teeth and so
> > > forth and it draws it up and then writes the g-code 
> depending on your
> > > cutter.
> > >
> > > They don't have a rack gear routine (yet) but we played 
> with that a bit
> > > and it looked like the sides of the teeth are flat faced 
> where the exact
> > > angle and distance between are a product of the nature of the gear
> > > running in them.  The rack's tooth profile is certainly 
> not a simple
> > > negative of the involute tooth of the gear that runs in it.
> > >
> > > It was an interesting thought and drafting experiment but 
> I stayed well
> > > short of the real math to make 'em.
> > >
> > > Rayh
> >
> >The rack tooth form is the basis for involute gears, everything else
> >comes from this. The rack form is described in Machinery's 
> handbook and
> >here:
> >http://www.sdp-si.com/d785/html1/D785T007_2.html
> >
> >The straight sides are at the pressure angle (20 or 14.5 degrees
> >usually). This trapezoidal shape, as a hob, fly cutter, or 
> standard #8
> >gear cutter, can be used with an A axis to cut all of the 
> gear diameter
> >sizes with the corresponding pitch. The other key feature, 
> is the base
> >circle which is derived from the pressure angle lines placed 
> with their
> >intersection on the pitch circle.
> >http://www.sdp-si.com/d785/html1/D785T018_1.html
> >
> >The diagram shows one pressure angle line, the other is just 
> a mirror of
> >it. The point(s) of contact are on this line and since the line and
> >contact point can be thought of as an unwinding string, the 
> sum of the
> >contact points forms an involute of the base circle.
> >
> >I have Synergy, but I am trying to come up with an open-source gear
> >utility. I have a way to go.
> >--
> >Kirk Wallace
> >http://www.wallacecompany.com/machine_shop/
> >http://www.wallacecompany.com/E45/index.html
> >California, USA
> >
> >
> >-
> -
> >Crystal Reports - New Free Runtime and 30 Day Trial
> >Check out the new simplified licensing option that enables
> >unlimited royalty-free distribution of the report engine
> >for externally facing server and web deployment.
> >http://p.sf.net/sfu/businessobjects
> >___
> >Emc-users mailing list
> >Emc-users@lists.sourceforge.net
> >https://lists.sourceforge.net/lists/listinfo/emc-users
> 
> __
> Andre' B. 
> 
> 
> --
> 
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> 


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[Emc-users] Servo Control

[Emre Ersin]

Hi,

I am planning to build a robot arm which holds a driller. (it means 6dof 
afaik)

Is there a way to write a configuration to control 3 std. R/C servos 
directly? Where do I have to look? The way which seems easy to me is 
burning a PIC interface  prog which takes parport information and 
emulates stepper motors. Is there a direct way? As you can imagine it 
will reduce operation speed of machine too much.

Thanks
-- 

Emre Ersin

 



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Re: [Emc-users] Rotary Axis Designs

[Rainer Schmidt]

Haha.. The Belt Stiffness fools many. It's a PU timing belt which is
steel loaded. I tensioned it to 160lbs and the think sounds like a
guitar string. There is NO flex whatsoever. If there would be... most
cars would sink their valves into the cylinders more often than not.
The ratio is 1:3 and the stepper has 10 steps micro stepping. So I get
2000 steps per revolution times three. So I get 360/6000 degree
resolution which I could reproduce. If you would use a servo then you
can easily tripple that resolution with the right encoder. I chose a
stepper there because I wanted the high holding torque for unbalanced
work. Did I mention that it is FAST.

I also hae a sherline table on my Taig mill. And that's where it
belongs. I mill pen's with it and for that it's nice and very precise.
However, it does wear as all the stuff does which is not designed for
CNC kinda moves (which means a LOT of moves). And for the price of it
I milled my monster 4th. The timkin bearings are sitting in those 3
Inch AL blocks 8))). Derived from the shaft all measurements became
slightly beefy lol.

I also milled a groove into the bottom of the head and the tailstock
so alignment is easy. The biggest challenge was to bore that hole for
the MT3 sleeve. Compared to the tailstock I must say that the sherline
tailstock resembles a toothpick.

If you wish to mill tiny stuff and not to often then go for the
sherline table combo. If you need a quick turning cnc solution then
build one. I took a look at all sorts of tables and the ones suitable
would have been precision US or European made rotary tables which
would have cost me several thousand dollars and that for no other
reason but backlash. Na building one or having one build is
probably the best way to go as there are no affordable CNC tables.

Yesterday I used it to cut a thread into a larger hole in a wood
block. No way to do that with the slow turning regular tables. it has
to go 'swish swish swish' and not scrp, screechh,
squl. haha.

Have a good memorial day and recall what others did for your
particular country so they did not do it in vain.
Rainer

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Re: [Emc-users] [Fwd: Heiz CNC - emc configuration] 5th axis

[Greg Michalski]

> -Original Message-
> From: Robert von Knobloch [mailto:b...@engelking.de]
> Subject: [Emc-users] [Fwd: Heiz CNC - emc configuration] 5th axis
> 
> Peter wrote:
> 
> Hello Robert,
> 
> Have you ever thought about making the 5th axis to your Heiz machine?
The
> Heiz controller is capable for 4 axis, and with another LPT port and
> controller and step motor would it be possible to drive the 5th axis?
What
> do you think?
> 
> Best Regards,
> Peter
> 
> 
> I can see no reason why not, except maybe the difficulty of generating
> gcode from cad to drive it.
> EMC can handle up to 6 axes.
> I do not have a reason for a 5th. axis on my machine.
> What do you want to use it for ?
> 
> Best regards,
> Robert

I think you meant to say EMC could handle 9 axes. (XYZABCUVW)  :-)

Greg
www.distinctperspectives.com


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[Emc-users] [Fwd: Heiz CNC - emc configuration] 5th axis

[Robert von Knobloch]

Peter wrote:

Message: 4
Date: Thu, 21 May 2009 08:31:02 +0200
From: P?ter Bocska 
Subject: Re: [Emc-users] [Fwd: Heiz CNC - emc configuration] 5th axis
To: "Enhanced Machine Controller (EMC)"

Hello Robert,

Have you ever thought about making the 5th axis to your Heiz machine? The
Heiz controller is capable for 4 axis, and with another LPT port and
controller and step motor would it be possible to drive the 5th axis? What
do you think?

Best Regards,
Peter
  

I can see no reason why not, except maybe the difficulty of generating
gcode from cad to drive it.
EMC can handle up to 6 axes.
I do not have a reason for a 5th. axis on my machine.
What do you want to use it for ?

Best regards,
Robert

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Re: [Emc-users] Charge pump frequency

[Leslie Newell]

Ah, the fog is clearing. I hadn't grasped the relationship between 
loadrt and addf. So basically loadrt initializes the module then addf 
connects it to a thread and runs it.

Thanks,
Les



Jeff Epler wrote:
> On Mon, May 25, 2009 at 12:32:44AM +0100, Leslie Newell wrote:
>> How do you specify which thread it is on?
> 
> this is specified on the halcmd 'addf' line for the function and shown
> by halcmd 'show thread'.
> 
>> Is HAL event driven or a state machine? For instance if I change a pin 
>> that is connected to other modules, do those modules get notified 
>> immediately or does the change get processed on the next cycle?
> 
> Realtime components are invoked in a specified order (the one shown by
> halcmd show thread) at the specified interval (also shown by halcmd
> show thread).  If the execution order is first A then B, the B function
> will see the outputs updated by A.  The next time A is invoked (e.g.,
> after 25us has passed if it's in a BASE_PERIOD of 25000) it will see the
> outputs updated by B.
> 
> When functions in two different realtime threads, or some non-realtime
> code is involved, then the ordering guarantee is only that they are not
> re-ordered with respect to each other.
> 
> The model of hal is discussed extensively in the first chapter of the HAL 
> manual,
> http://www.linuxcnc.org/docs/2.3/HAL_User_Manual.pdf
> 
> Jeff
> 

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