Re: EMC minimill option/Parallel port issues
Hi,
I have one somewhere - it was just a circuit I got off a web page. I'll
look it out and post it to the dropbox as soon as I can. It won't be for a
few days though as I'm going away for a week in the sun!!! - I hope ;o)
Ian
--
Ian W. Wright
Sheffield UK
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----- Original Message ----- From: Paul Devey <paul_devey@...> To: <CAD_CAM_EDM_DRO@...> Sent: 03 March 2000 20:01 Subject: Re: [CAD_CAM_EDM_DRO] EMC minimill option/Parallel port issues From: "Paul Devey" <paul_devey@...>
Ian,
Do you have a schematic that you can share with us?
Paul
|
From: "Darrell" <dgehlsen@...>
I thought I read that you can set the acceleration separately for each axis
but I only find one setting. It's not exactly the same thing, but you can vary the P gain with similar effect. Matt
|
Darrell Gehlsen wrote: From: "Darrell Gehlsen" <dgehlsen@...>
Got EMC to load to the point that I can get it out of ESTOP and turn
the machine on using xemc or the tk interface.
Now when I try to move an axis I get a following error message. I
think it is because it is looking for an encoder input (which I do not
have).
I am using the frequency mode and minimill io You can turn the following error parameter up to a larger value to prevent following errors. Or, maybe, it is due to the P gain being too low. If the errors only occur at higher speeds, turn up P for each axis to a higher value. If it ocurrs at low jog speeds, then turn up the error limit to several inches. Jon
|
Ok, I got it working. The problem was in the OUTPUT_SCALE it came set at
1.000 0.0 and it needed to be 1000.0 0.0.
I thought I read that you can set the acceleration separately for each axis
but I only find one setting.
Darrell
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----- Original Message ----- From: Tim Goldstein <timg@...> To: <CAD_CAM_EDM_DRO@...> Sent: Friday, March 03, 2000 4:34 PM Subject: Re: [CAD_CAM_EDM_DRO] Feb 25 From: "Tim Goldstein" <timg@...>
You are using the right parts. I think your problem is your P value is set
too low. If it is too low the axis actual position will fall behind the
commanded position and you will get a follow error. It has nothing to do
with looking for an encoder input as in emcfreqmot the encoder input is
virtual. I find that on my system 150 is about the minimum value I can use
for P and that at 1000 the motors are getting driven faster than they can
respond and my max speed suffers.
Ray Henry posted a great description of the PID parameters written in
laymans terms on the EMC mailing list. It follows for the benefit of this
group:
Tim and other new freqmod/smdromod users.
This is a rather long post about P but this axis tuning stuff becomes
critical for stepper users with these new tools. This is an IMHO view of
P, I, D. (with flame suit in place) BTW I've seen some excellent stuff on
the web regarding PID tuning but don't have specific links handy. There
are also a bunch of auto tuning and computational tuning procedures but I
know nothing about any of them.
All three variables (6+ really) look at what is happening between commanded and actual position in the emc. My comments below may be a bit
unsatisfying for those who are accustomed to very precise things but they
come from a number of years of twiddling with servo controls.
P - process variable.
---------------------
This is the gain control. It is a bit like the volume on a music system.
If it is set too low you can't follow the lyrics. If it's set too high the windows rattle and the neighbors fuss.
Some authors refer to P as proportional band. Think of it as a pair of
lines, one ahead of the commanded position and one behind it. Actual
position should be somewhere between the lines. If the actual position is
farther behind then that below line the controller will run the axis flat
out to reach the slower line. Conversely, if the actual position is ahead
of the above line the controller will do all it can to bring actual
position down to that upper bound.
As long as the actual position is between the lines, the controller will
ramp gain up and down so that actual approaches commanded.
The larger the P number the narrower the space between these lines. Set P
too low and your axis works like a dedicated couch potato during super bowl or world soccer finals -- even a fire may not rouse it. This condition is
rather easy to spot because the axis is sluggish.
Set P too high and your axis will develop palsy. On most machines you can
hear this condition by putting your ear to the motor. You may want to do
this when others aren't watching -- or use a stethoscope or a long socket
extension -- or perhaps the graph function.
Palsy will sound like a hum or grind when the motor is sitting still or
moving very slowly. You can also feel palsy if you wrap your hand around
the ball screw or grip the drive belt or pulley. (disclaimer -- This
demonstration is done by a professional with only three remaining fingers,
don't try this at home)
Deadband may mask too much P when a motor is sitting still so you may want
to move the axis very slowly and listen to the sounds around each step. If the axis keeps up with commanded position at high speed and during
acceleration and there is not a lot of ringing, grinding, jumping at very
low speed, then you are real close.
I - Integral variable.
----------------------
Integral works a bit like a shock absorber. Any change in either actual or commanded position gets rounded off or averaged in so that
acceleration/deceleration brought about by P is absorbed and released more
slowly over time.
No integral and you get the full P effect of change in commanded position.
Too much integral and the axis seems to wander off on it's own without much regard for P. A little integral may smooth out some of the frequency jumps when a stepper is running right near one of those troublesome rates.
D - Derivative variable
-----------------------
Derivative works like passing gear for acceleration or a jake-brake for
stopping. Whenever commanded position changes rapidly, d will really kick
the amp/motor in the *** to follow the rate-of-change of the axis command
rather than the difference between commanded and actual position.
Derivative works against inertia so if you've got lots of iron to start or
stop dial some in. But derivative will increase palsy so you have to
balance it against gain.
T - Test
--------
The final proof of tuning is in the cutting. So after your best guess with all the watching, hearing, feeling done to each axis, get out a chunk of
soft aluminum, a small end or ball mill, and begin to mill circles or arcs
that pass 90 degrees between each pair of axis. I like outside circles
because you can hold them up to the light and see how the finish looks near the quadrants.
Digital systems will give you some steps as one axis approaches zero and
the other approaches the set feedrate so don't expect a perfect mirror arc
finish. Backlash and backlash compensation also affect the appearance
here. Servo drives will work better than steppers. (digital vs analog)
But the smoother the saw teeth the better.
Be prepared to spend some metal on this! And make a list of your settings, changes, and a better/worse judgement about the result of each change. On
occasion I've spent pages of paper and made piles of swarf to get a
stubborn machine to where I wanted it.
Good luck and may the force be with you.
Ray
--- END OF REPOST----
I hope that helps. I have found that emcfreqmot does require you to fiddle
witht he settings a lot more, but once you get them right it is just
impressive in the speed it offers. There is also a setting in emcfreqmot.c
(located in /usr/local/nist/emc/src/emcmot if I remember correctly) that
controls the base period of the frequency. Setting this value to a smaller
value will improve the top speed you can achieve. I find it by searching
for:
period =
(yes, there is a single space between period and =)
The default is 20 and on an AMD K6 2D 500 mHz I am able to use a value of 10 and Matt Shaver is using a value of 12 on a PII 350 if memory serves me
right. After you edit this value you must recompile by entering:
make PLAT=rtlinux_09J all
from in the directory the file is in.
Tim
[Denver, CO]
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You are using the right parts. I think your problem is your P value is set
too low. If it is too low the axis actual position will fall behind the
commanded position and you will get a follow error. It has nothing to do
with looking for an encoder input as in emcfreqmot the encoder input is
virtual. I find that on my system 150 is about the minimum value I can use
for P and that at 1000 the motors are getting driven faster than they can
respond and my max speed suffers.
Ray Henry posted a great description of the PID parameters written in
laymans terms on the EMC mailing list. It follows for the benefit of this
group:
Tim and other new freqmod/smdromod users.
This is a rather long post about P but this axis tuning stuff becomes
critical for stepper users with these new tools. This is an IMHO view of
P, I, D. (with flame suit in place) BTW I've seen some excellent stuff on
the web regarding PID tuning but don't have specific links handy. There
are also a bunch of auto tuning and computational tuning procedures but I
know nothing about any of them.
All three variables (6+ really) look at what is happening between commanded
and actual position in the emc. My comments below may be a bit
unsatisfying for those who are accustomed to very precise things but they
come from a number of years of twiddling with servo controls.
P - process variable.
---------------------
This is the gain control. It is a bit like the volume on a music system.
If it is set too low you can't follow the lyrics. If it's set too high the
windows rattle and the neighbors fuss.
Some authors refer to P as proportional band. Think of it as a pair of
lines, one ahead of the commanded position and one behind it. Actual
position should be somewhere between the lines. If the actual position is
farther behind then that below line the controller will run the axis flat
out to reach the slower line. Conversely, if the actual position is ahead
of the above line the controller will do all it can to bring actual
position down to that upper bound.
As long as the actual position is between the lines, the controller will
ramp gain up and down so that actual approaches commanded.
The larger the P number the narrower the space between these lines. Set P
too low and your axis works like a dedicated couch potato during super bowl
or world soccer finals -- even a fire may not rouse it. This condition is
rather easy to spot because the axis is sluggish.
Set P too high and your axis will develop palsy. On most machines you can
hear this condition by putting your ear to the motor. You may want to do
this when others aren't watching -- or use a stethoscope or a long socket
extension -- or perhaps the graph function.
Palsy will sound like a hum or grind when the motor is sitting still or
moving very slowly. You can also feel palsy if you wrap your hand around
the ball screw or grip the drive belt or pulley. (disclaimer -- This
demonstration is done by a professional with only three remaining fingers,
don't try this at home)
Deadband may mask too much P when a motor is sitting still so you may want
to move the axis very slowly and listen to the sounds around each step. If
the axis keeps up with commanded position at high speed and during
acceleration and there is not a lot of ringing, grinding, jumping at very
low speed, then you are real close.
I - Integral variable.
----------------------
Integral works a bit like a shock absorber. Any change in either actual or
commanded position gets rounded off or averaged in so that
acceleration/deceleration brought about by P is absorbed and released more
slowly over time.
No integral and you get the full P effect of change in commanded position.
Too much integral and the axis seems to wander off on it's own without much
regard for P. A little integral may smooth out some of the frequency jumps
when a stepper is running right near one of those troublesome rates.
D - Derivative variable
-----------------------
Derivative works like passing gear for acceleration or a jake-brake for
stopping. Whenever commanded position changes rapidly, d will really kick
the amp/motor in the *** to follow the rate-of-change of the axis command
rather than the difference between commanded and actual position.
Derivative works against inertia so if you've got lots of iron to start or
stop dial some in. But derivative will increase palsy so you have to
balance it against gain.
T - Test
--------
The final proof of tuning is in the cutting. So after your best guess with
all the watching, hearing, feeling done to each axis, get out a chunk of
soft aluminum, a small end or ball mill, and begin to mill circles or arcs
that pass 90 degrees between each pair of axis. I like outside circles
because you can hold them up to the light and see how the finish looks near
the quadrants.
Digital systems will give you some steps as one axis approaches zero and
the other approaches the set feedrate so don't expect a perfect mirror arc
finish. Backlash and backlash compensation also affect the appearance
here. Servo drives will work better than steppers. (digital vs analog)
But the smoother the saw teeth the better.
Be prepared to spend some metal on this! And make a list of your settings,
changes, and a better/worse judgement about the result of each change. On
occasion I've spent pages of paper and made piles of swarf to get a
stubborn machine to where I wanted it.
Good luck and may the force be with you.
Ray
--- END OF REPOST----
I hope that helps. I have found that emcfreqmot does require you to fiddle
witht he settings a lot more, but once you get them right it is just
impressive in the speed it offers. There is also a setting in emcfreqmot.c
(located in /usr/local/nist/emc/src/emcmot if I remember correctly) that
controls the base period of the frequency. Setting this value to a smaller
value will improve the top speed you can achieve. I find it by searching
for:
period =
(yes, there is a single space between period and =)
The default is 20 and on an AMD K6 2D 500 mHz I am able to use a value of 10
and Matt Shaver is using a value of 12 on a PII 350 if memory serves me
right. After you edit this value you must recompile by entering:
make PLAT=rtlinux_09J all
from in the directory the file is in.
Tim
[Denver, CO]
|
Got EMC to load to the point that I can get it out of ESTOP and turn the machine on using xemc or the tk interface.
Now when I try to move an axis I get a following error message. I think it is because it is looking for an encoder input (which I do not have).
I am using the frequency mode and minimill io
Darrell
|
Re: Stepper resonance - not a problem
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Show quoted text
----- Original Message ----- From: <beer@...> If the motor stopped on a particular half-position step as a result of
insufficient torque, it may not move on the next "full" step either. Hi Alen, If thats the case, it probly wouldn't work in full step mode either. What I was trying to say was that if it had insufficant torque to move to the half step position, on the next full step - it would go from one full step to the next just as if it was full stepping to begin with. The constant torque "secret" is to increase the current to the winding,
when only one winding is on. Appropriately scaled, this will result in
constant motor torque for each position.
The theory is clear and well understood. For any given angle, the
current relationship should be sin(a) cos(b). For simple half-step, this
translates to increasing the current by 40% when only a single winding
is on.
I had thought about doing this, my controller has the capability to adjust the current sense reference voltage from 50 - 100%, with a resistor change it could do 60/100. But are the motors ratings limited by the temprature rise - or core saturation? Note that at no time does the current through the windings exceed the
current in the both windings on position, so no motor overheating
should result. ( Your 4 amp steppers, for example, will have 8 amps
total in "both windings on" position and 5.6 amps though one winding
only in the "half" step position ) If the motor is stopped in the
one-winding on position, though, the motor current must be reduced, or
the winding will overheat. My controller does a power saver function where the current is reduced automaticaly if it has nor recieved a step pulse in 1 second - it resumes full power imediatly when a step pulse arrives.
I've been working with DanM on this for a bit, and Dan has found that
going to quarter step solves almost all resonance problems, and that
going finer than that, to so-called microstepping is really not
necessary.
This is the second time If seen 1/4 stepping mentioned - could you explain how this works? Do you have to be able to set different current levels simultaniously when two coils are energized? Joel
|
Re: EMC minimill option/Parallel port issues
In a message dated 03-March-00 07:28:26 Central Standard Time,
Ian@... writes:
<< I haven't heard of one of these, but I use a home-built board which is
simply a handful of LEDs hooked up to a ULN2003 driver chip which plugs into
the parallel port and gives a clear indication of what is happening there.
For switch inputs, you can simply wire a 4k7 resistor from the pin to a 5v
supply line and then pull it low with a switch to ground. I would think that
this is a better way than relying on a program running in the same computer
as any faults in the computer are likely to get mimiced or ignored as when
EMC is running. >>
Right on, Ian! I have done the same thing, myself, for same reason!
|
Re: EMC minimill option/Parallel port issues
Ian, Do you have a schematic that you can share with us? Paul I haven't heard of one of these, but I use a home-built board which is
simply a handful of LEDs hooked up to a ULN2003 driver chip which plugs into the parallel port and gives a clear indication of what is happening there.
For switch inputs, you can simply wire a 4k7 resistor from the pin to a 5v
supply line and then pull it low with a switch to ground. I would think that this is a better way than relying on a program running in the same computer as any faults in the computer are likely to get mimiced or ignored as when
EMC is running.
Ian
|
Re: EMC minimill option/Parallel port issues
Dave This is just about what backplot does. Tkbackplot is a part of the latest emc release but backplot.ini and backplot.run are in the linuxcnc.org dropbox as bkplot1.tgz bundle. Ray Message: 3 [CAD_CAM_EDM_DRO] Digest Number 387
Date: Thu, 2 Mar 2000 17:28:37 -500
From: daveland@...
Subject: EMC minimill option/Parallel port issues How about a "stepperdemo.ini" for a system with nothing connected? This would
allow a demo to run out of the chute so newbees can get it going? I volunteer to write it along with a description.... If I do, Will Fred put it in the future distibutions?
|
Re: Stepper resonance - not a problem
On 3 Mar, CAD_CAM_EDM_DRO@... wrote: Message: 1
Date: Thu, 2 Mar 2000 11:39:34 -0500
From: "Joel Jacobs" <jj@...>
Subject: Stepper resonance - not a problem
I had been reluctant to use half-steps because every other step only one
field energizes and I thought it wouldn't have as much torque - after
thinking about it a bit, that's wrong. It still gets full power every other
step and even if it couldn't move at all on the half step it would surely
move on the next full step. I think you're a bit mistaken on a couple of things here. If the motor stopped on a particular half-position step as a result of insufficient torque, it may not move on the next "full" step either. That's the whole point programmers are trying to make with SMOOTH accelerations tied to hardware timers. Resonance is a problem that can cause missed steps, but "unsmooth" accelerations will also cause missed steps. The constant torque "secret" is to increase the current to the winding, when only one winding is on. Appropriately scaled, this will result in constant motor torque for each position. The theory is clear and well understood. For any given angle, the current relationship should be sin(a) cos(b). For simple half-step, this translates to increasing the current by 40% when only a single winding is on. Note that at no time does the current through the windings exceed the current in the both windings on position, so no motor overheating should result. ( Your 4 amp steppers, for example, will have 8 amps total in "both windings on" position and 5.6 amps though one winding only in the "half" step position ) If the motor is stopped in the one-winding on position, though, the motor current must be reduced, or the winding will overheat. I've been working with DanM on this for a bit, and Dan has found that going to quarter step solves almost all resonance problems, and that going finer than that, to so-called microstepping is really not necessary. Be aware that absolute positioning is not as accurate in any of the intermediate positions, and this position error is increased as the steps get finer and finer. ( Yet another reason to avoid uStepping ) Moral: Don't change your pulley ratios to keep the speed up. Alan -- Alan Rothenbush | The Spartans do not ask the number of the Academic Computing Services | enemy, only where they are. Simon Fraser University | Burnaby, B.C., Canada | Agix of Sparta
|
Ian, I was able to download and compile the Feb. 29 2.2 release with no problems. Is the disk partition you're installing EMC on full? The EMC tarball has other tarballs in it. Part of the install process is to untar these before compiling. If the partion is full then some of the files may be getting truncated. Try this: cd <to the root EMC directory> df . The df command will tell you how much space is available in the partition. If there aren't any error when you initialy untar the file you downloaded from NIST then I think it's a safe bet that the file is ok. Drew On Mar 3, 10:22am, Ian Wright wrote: Subject: [CAD_CAM_EDM_DRO] Version 2.2.* EMC
From: "Ian Wright" <Ian@...>
Hi,
Has anyone else tried the 29 Feb build of EMC for RH6.1? For some reason I
can't get it to compile properly and run. The file I downloaded has the
same byte count as the one on the site but I get 'unexpected end of file'
errors when I try to install it. It may, of course, be a bad download
although that usually messes up the byte count or it may be that I am
running the latest (2.2.14) precompiled RTlinux kernel (which seems OK as it
will run the 'Frank Zappa' etc. tests) and that there is something different
between this and the last kernel. Any thoughts?
Ian
--
Ian W. Wright
Sheffield UK
-- End of excerpt from Ian Wright -- Drew Rogge drew@...
|
Hi Ian,
Back on 1 March I downloaded the 29Feb2000 EMC source (2.2.13), and
built it (under RH6.0 and 2.2.13 rtl2.0 patched kernel) without any
significant difficulty. The demo runs fine, although that's as much as
I've had time to do with it. Where do you get the "unexpected end of
file"? Do a "gzip -d" on the .tgz file you downloaded; if you get the
unexpected EOF there, then I think you have a bad download.
If that works ok, then you are pretty close to being guaranteed that you
have a "good" download, and you can go ahead and "tar xvf" the
decompressed tarball. You "SHOULDN'T" get an unexpected EOF in that
step. Any EOF problems from there on out is something else. If the EOF
is occurring during the "./install" script, it would be worthwhile, if
you aren't already doing this, to make a log of all install messages
from STDOUT and STDERR. The easiest way is "./install &>logfile", where
logfile is the name of the log file. At least that way you have the log
to help determine where it bombs. Good luck.
Ian Wright wrote:
toggle quoted message
Show quoted text
From: "Ian Wright" <Ian@...>
Hi,
Has anyone else tried the 29 Feb build of EMC for RH6.1? For some reason I
can't get it to compile properly and run. The file I downloaded has the
same byte count as the one on the site but I get 'unexpected end of file'
errors when I try to install it. It may, of course, be a bad download
although that usually messes up the byte count or it may be that I am
running the latest (2.2.14) precompiled RTlinux kernel (which seems OK as it
will run the 'Frank Zappa' etc. tests) and that there is something different
between this and the last kernel. Any thoughts?
Ian
--
-------------------------------
George Fouse,
President
G F I Consulting
-------------------------------
|
Re: EMC minimill option/Parallel port issues
toggle quoted message
Show quoted text
----- Original Message ----- From: <daveland@...> Is there a utility people use in linux to scan the port bit input bit values and display them or manually set the outputs for debug ( not while emc is running)? I need one!!! I haven't heard of one of these, but I use a home-built board which is simply a handful of LEDs hooked up to a ULN2003 driver chip which plugs into the parallel port and gives a clear indication of what is happening there. For switch inputs, you can simply wire a 4k7 resistor from the pin to a 5v supply line and then pull it low with a switch to ground. I would think that this is a better way than relying on a program running in the same computer as any faults in the computer are likely to get mimiced or ignored as when EMC is running. Ian -- Ian W. Wright Sheffield UK
|
Hi,
Has anyone else tried the 29 Feb build of EMC for RH6.1? For some reason I
can't get it to compile properly and run. The file I downloaded has the
same byte count as the one on the site but I get 'unexpected end of file'
errors when I try to install it. It may, of course, be a bad download
although that usually messes up the byte count or it may be that I am
running the latest (2.2.14) precompiled RTlinux kernel (which seems OK as it
will run the 'Frank Zappa' etc. tests) and that there is something different
between this and the last kernel. Any thoughts?
Ian
--
Ian W. Wright
Sheffield UK
|
Re: EMC minimill option/Parallel port issues
There really does need to be some sort of diagnostic to tell you why you can
not get out of ESTOP.
Today if I hit F1 enough times it will eventually say ESTOP RESET but then I
still can not turn the machine on and it was working yesterday and I have
made no changes. It is acting like I have noise on one of the lines but I
have no way to find out where to start.
Darrell
toggle quoted message
Show quoted text
----- Original Message ----- From: <daveland@...> To: <CAD_CAM_EDM_DRO@...> Sent: Thursday, March 02, 2000 2:28 PM Subject: [CAD_CAM_EDM_DRO] EMC minimill option/Parallel port issues From: daveland@...
Matt,Darrell
Ah that is why. I lost my hard drive and rebuilt with a newer
EMC. My .ini file was lost with the drive so I could not remember what I did. I missed that..But I needed to get the parallel card in anyway.
Is there a utility people use in linux to scan the port bit input bit values and display them or manually set the outputs for debug ( not while emc is running)? I need one!!!
BTW Xemc,Yemc do not give you an error message when you try to turn ESTOP OFF and there is a limit switch or other fault. It should tell you why it cannot turn estop off. Say " Xlimit active..Cannot leave Estop state" Is the info avalible to the YEMC interface to do this?
How about a "stepperdemo.ini" for a system with nothing connected? This would allow a demo to run out of the chute so newbees can get it going? I volunteer to write it along with a description.... If I do, Will Fred put it in the future distibutions?
dave
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Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the discussion of shop built systems in the above catagories. To Unsubscribe, read archives, change to or from digest.
Go to:
Log on, and you will go to Member Center, and you can make changes there.
For the FAQ, go to
bill,
List Manager
|
Stepper resonance - not a problem
I spent the weekend and early part of this week polishing up the software on
my chopper drive and took the plunge last night and hooked it up to my mill.
The first move was real slow and it sounded like someone running a jack
hammer. Most of the racket was coming from the handles that were still
attached to the other end of the lead screws. I removed the handles and was
much better. I ran it through it's complete speed range with a circular
interpolation - only one axis moving though.
There were a couple speeds that made a pretty loud 'buzz' - found out that
was coming from the tooth belt. After a few cycles I went back to 0,0 and it
had not lost any steps.
I had been reluctant to use half-steps because every other step only one
field energizes and I thought it wouldn't have as much torque - after
thinking about it a bit, that's wrong. It still gets full power every other
step and even if it couldn't move at all on the half step it would surely
move on the next full step. So I tried half step and the machine moved very
smoothly at all speeds. Ran several tests and even took some cuts on a
chunk of aluminum. Never lost a step. I'm real happy with this driver.
I'm running the motor at 4amps/phase and at motor lock it's drawing about
1 amp from my 40 volt supply. At 20-25 ipm feed it draws 2 amps from the
supply. (8000 steps per inch). 20 ipm is the fastest speed that the field
coils can reach 4 amps but the machine rapids at 25 ipm just fine.
I think I'll put amp meters on my control, seems like a good indication
of machine friction/cutting loads.
That was all...
Joel
|
patv@... wrote:
I'm into model railroading and I've been trying to make HO scale parts
using automated techniques. Unlike most folks, I'm not as concerned about
power as I am about the ability to machine details. For example, a 1"
dome representing a rivet in HO scale is 0.0115" in diameter and 0.0057"
high. Spacing in between these may go as close as a scale 1.5" centers or
only 0.0057" gap between domes. As you can see, this would mean I need
some very tiny end and ball mills.
[Offhand, I'd say it would be a lot easier to make these in reverse, then cast
your final material against the milled part, using it as a mold. If you need a
metal part, you can cast wax against the mold, (using a release) then cast it
using the lost-wax process. ]
So, anyone have any experience with this type of work? What process do
the commercial boys use when making their molds? Are they using exotic
techniques? Also, do any of these CAD post processors like DeskProto allow
for programming of cutter geometries, such as conical as opposed to simple
ball and end mill diameters?
Pat
[Yes, DeskProto has preset conical cutters in its tool library, which can be
customized to match your tool. You can download a working (but time-limited)
demo at . ]
Andrew Werby
Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
|
EMC minimill option/Parallel port issues
Matt,Darrell
Ah that is why. I lost my hard drive and rebuilt with a newer
EMC. My .ini file was lost with the drive so I could not remember what I did.
I missed that..But I needed to get the parallel card in anyway.
Is there a utility people use in linux to scan the port bit input bit values
and display them or manually set the outputs for debug ( not while emc is running)?
I need one!!!
BTW Xemc,Yemc do not give you an error message when you try to turn ESTOP OFF
and there is a limit switch or other fault. It should tell you why it cannot
turn estop off. Say " Xlimit active..Cannot leave Estop state" Is the info
avalible to the YEMC interface to do this?
How about a "stepperdemo.ini" for a system with nothing connected? This would
allow a demo to run out of the chute so newbees can get it going? I volunteer
to write it along with a description.... If I do, Will Fred put it in the future
distibutions?
dave
|
Found new surplus 3-stack NEMA 42 motors (1850 oz-in)
I found 15 Sigma NEMA 42 motors, seller says 1850 oz in, still trying
straighten out data).
I ordered one. Anyone else interested...they're $275 + shipping (roughly
23.5 #)
Murray
toggle quoted message
Show quoted text
-----Original Message----- From: CAD_CAM_EDM_DRO@... <CAD_CAM_EDM_DRO@...> To: CAD_CAM_EDM_DRO@... <CAD_CAM_EDM_DRO@...> Date: Tuesday, February 29, 2000 6:42 AM Subject: [CAD_CAM_EDM_DRO] Digest Number 384 ------------------------------------------------------------------------
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Intro or 9.9% Fixed APR and no hidden fees. Apply NOW!
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Go to:
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------------------------------------------------------------------------
There are 15 messages in this issue.
Topics in today's digest:
1. RE: resonance and controllers
From: "Harrison, Doug" <dharrison@...>
2. xyz table for sale?
From: "Jim Fackert" <jfackert@...>
3. RE: Wonderboard PC interface original message!
From: "Harrison, Doug" <dharrison@...>
4. RE: Wonderboard PC interface original message!
From: "jguenthe" <jguenthe@...>
5. Re: re - Wonderboard PC interface
From: "D.F.S." <dfs@...>
6. RE: DRO UPDATE
From: "Terry May" <tmay@...>
7. Feedback wanted
From: Charles Gallo <Charlie@...>
8. Re: RE: DRO UPDATE
From: "A. G. Eckstein" <axtein@...>
9. DRO
From: Charles Hopkins <chopkins@...>
10. Re: DRO
From: "Tim Goldstein" <timg@...>
11. Re: DRO
From: "Jim Geib" <jimg47@...>
12. For sale: two used Superior Electric 840 oz-in steppers
From: "Multi-Volti Devices" <multi-volti@...>
13. Re: re - Wonderboard PC interface
From: ptengin@...
14. Re: For sale: two used Superior Electric 840 oz-in steppers
From: ptengin@...
15. Re: is my software stable?
From: "Peter Smith" <peter@...>
___________________________________________________________________________ ____ ___________________________________________________________________________ ____
Message: 1
Date: Mon, 28 Feb 2000 09:18:25 -0500
From: "Harrison, Doug" <dharrison@...>
Subject: RE: resonance and controllers
-----Original Message-----
From: Joe Vicars [SMTP:jvicars@...]
Sent: Friday, February 25, 2000 1:59 PM
To: CAD_CAM_EDM_DRO@...
Subject: [CAD_CAM_EDM_DRO] resonance and controllers
From: Joe Vicars <jvicars@...>
I don't understand how the software control contributed to the
resonance problem that Tim described. The software controller just
outputs a square wave of varying frequency. If you have control over
your instantaneous start, accel and decel, then you should be able to
find an operating range that works. What am I missing?
Some programs are not very good at accurately spacing the step
pulses. The variation in timing shows up as harmonics and the effects are
significant.
Doug
___________________________________________________________________________
____ ___________________________________________________________________________ ____
Message: 2
Date: Mon, 28 Feb 2000 10:08:02 -0500
From: "Jim Fackert" <jfackert@...>
Subject: xyz table for sale?
Will the fellow who had the xyz router table with servos for sale please
email me off list?
Thanks,
Jim Fackert
jfackert@...
___________________________________________________________________________
____ ___________________________________________________________________________ ____
Message: 3
Date: Mon, 28 Feb 2000 15:20:27 -0500
From: "Harrison, Doug" <dharrison@...>
Subject: RE: Wonderboard PC interface original message!
Yes, we did get a little carried away with this one. I did manage to get
plenty of feedback, so much that I printed it into a big stack of paper
(more trees died) and took it home to read over the weekend. Thanks to all
who contributed.
I still have some more research to do before I commit to the final
specification. Perhaps I should clarify my goals, which have not changed.
The plan was to design a board with enough dummyproofing to use in
industrial applications yet simple enough to be inexpensive and quick to
build. I see the potential to use this board as an interface with several
parallel port step motor programs. However, CNCPro is the one program I
feel comfortable enough with to support for retrofits. That is the program
I am designing the board for. This is not meant to be a negative comment
on other software and I would be happy to work with developers of such programs if they wish to communicate their wants and needs. The info I have on most
of them is inadequate to work with.
The preliminary specification looks like this:
1. Separate board - not in PC. ( I may change this again if I succeed in
solving the DC-DC converter issue. Shucks! I might even go both ways.)
2. All input and output lines optoisolated.
3. All optos socketed.
4. Selection of optos to allow interchangability between cheap and high
speed optos for step/direction lines.
5. Sockets for optional SS relays on control lines.
6. On board 5V power.
7. DB25 and screw term capable input - your choice
8. DB9 and screw term options for step/dir lines.
9. Screw terms for limits, e-stop and control outs.
Several of you noted that it should not be necessary to use optos to drive
the step/dir amp inputs because most drivers are already optoisolated. Some of them aren't. But the main reason I stuck to my guns here is that there
is a tendency (and I've seen it) to use the same 5V supply for the driver
optos as is used for the limit switches. The drivers are protected but the
parallel port is tied to the limit lines. Not good. The data out optos
will be supplied by the PC 5V supply. Yes, I know this means more than just a single cable from the PC - another argument for making the board fit into
a PCI/ISA slot.
Doug
-----Original Message-----
From: Dean Sala [SMTP:adsala@...]
Sent: Friday, February 25, 2000 8:25 PM
To: CAD_CAM_EDM_DRO@...
Subject: [CAD_CAM_EDM_DRO] Wonderboard PC interface original message!
From: "Dean Sala" <adsala@...>
It seems as though this thread has went off on a tangent. I originally
replied to Doug about a parrallel interface card that I had designed to
work with CNCpro. But it seemed to never appear on the message board
except in Doug's reply to it. The reply is in the "Interface Update"
thread. Anyway, It seems as though some of you are getting confused
between what Doug is proposing and what I have done. So I want to clarify. I designed an proto typed external interface card to work with CNCpro. I
am building a homebrew CNC system so my design is catered towards that. I
believe Doug has different requirements and is building a more robust
board catered towards industrial use. Am I right? I'm not completely
clear about his requirements yet. But this is what I wrote to him.
Here is my original message to the "Interface update" thread.
-------------------------------------------------------------------------
- ----------------------------------------------------
Doug,
It's real great that you are trying to resolve this problem. I
completely agree that we need some sort of breakout box that could get us up to
speed faster. With an on board 5vPS, relays, screw in terminals and such. It
just so happens that I have already designed a proto type of this board
to work with CNCpro. Except that it does not use optoisolation on the
board.
I already have optoisolation on board my step drivers.
The proto type plugs into the parrallel port via cable. It has it's own
DB25 connector on one side and has a series of screw terminals on the
other.
It consists of a SN74S244 hex schmit trigger driver to drive the step and
direction data (3 or 4 axis or whatever)into the Step motor drivers. The
auxillary outputs, 3 in all so far (CNCPro at least) go through
ULN2003a's (that can be parralleled for more current) to drive 1amp 5v relays.
Also,
the homing inputs are hooked up to IR switches with their own terminal
block. The other inputs are just tied high through 4.7ks. I am still
working on the design and am thinking about making it more universal for
other parrallel port NC programs that aren't as configurable as CNCpro.
But
first I'm keeping it simple. I'm sorry for not getting ideas from you
guys
but now I have a feeling what you want. Are you sure you need
optoisolation
on the board too? I can add them right to the output of the SN74S244 but
then the opto isolators would be driving opto isolators. Maybe I can put
a
switch selector to bypass opto isolation if the step drivers have them.
Possible enhancements: On board 5V power supply(otherwise supply external
5v
PS). Connectors to connect 120v to stepper power supply with fuses etc.
Diagnostic LEDs connected to various outputs. Connectors for main power
switch and power light. Oh, limit switch connectors tied to turn off
stepper PS. There you have it! All-in-one wonder board!
About using the parrallel port for drive LED's....you should sink them of
course but it's always better to put a buffer inline like an S series TTL
driver which can source 28ma and sink 64ma perfect for this situation,
more
noise resistant and just what their made for. This way you don't have to
worry about how much power the parallel port can provide.
Good luck
Dean
-------------------------------------------------------------------------
- -------------------------------------------------------------
Please read Dougs reply in the "Interface Update" thread if you are
interested in his comments. It is a message stored under his name
If you have any questions about my design please reply. I left a few
things out of the above description.
Thanks
Dean Sala
------------------------------------------------------------------------
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Forever. If you have any desires to sell your products or services
online, or you want to expand your customer base for FREE, Come check
out Shabang!com FREE eStores!
------------------------------------------------------------------------
Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
discussion of shop built systems in the above catagories.
To Unsubscribe, read archives, change to or from digest.
Go to:
Log on, and you will go to Member Center, and you can make changes there.
For the FAQ, go to
bill,
List Manager
___________________________________________________________________________
____ ___________________________________________________________________________ ____
Message: 4
Date: Mon, 28 Feb 2000 15:48:51 -0500
From: "jguenthe" <jguenthe@...>
Subject: RE: Wonderboard PC interface original message!
Doug,
So what if it gets it's 5v supply from the PC and requires another cable.
It would seem to me that it could also get the 5v from a wall wort or some
other source besides the host PC, therefore my vote is for a separate board
and optional additional power supply. This way if space is a problem and
your host is a laptop, you could get the 5v from another source.
John Guenther
-----Original Message-----
From: Harrison, Doug [mailto:dharrison@...]
Sent: Monday, February 28, 2000 3:20 PM
To: 'CAD_CAM_EDM_DRO@...'
Subject: RE: [CAD_CAM_EDM_DRO] Wonderboard PC interface original message!
From: "Harrison, Doug" <dharrison@...>
Yes, we did get a little carried away with this one. I did manage to get
plenty of feedback, so much that I printed it into a big stack of paper
(more trees died) and took it home to read over the weekend. Thanks to all
who contributed.
I still have some more research to do before I commit to the final
specification. Perhaps I should clarify my goals, which have not changed.
The plan was to design a board with enough dummyproofing to use in
industrial applications yet simple enough to be inexpensive and quick to
build. I see the potential to use this board as an interface with several
parallel port step motor programs. However, CNCPro is the one program I
feel comfortable enough with to support for retrofits. That is the program
I am designing the board for. This is not meant to be a negative comment
on other software and I would be happy to work with developers of such programs if they wish to communicate their wants and needs. The info I have on most
of them is inadequate to work with.
The preliminary specification looks like this:
1. Separate board - not in PC. ( I may change this again if I succeed in
solving the DC-DC converter issue. Shucks! I might even go both ways.)
2. All input and output lines optoisolated.
3. All optos socketed.
4. Selection of optos to allow interchangability between cheap and high
speed optos for step/direction lines.
5. Sockets for optional SS relays on control lines.
6. On board 5V power.
7. DB25 and screw term capable input - your choice
8. DB9 and screw term options for step/dir lines.
9. Screw terms for limits, e-stop and control outs.
Several of you noted that it should not be necessary to use optos to drive
the step/dir amp inputs because most drivers are already optoisolated. Some of them aren't. But the main reason I stuck to my guns here is that there
is a tendency (and I've seen it) to use the same 5V supply for the driver
optos as is used for the limit switches. The drivers are protected but the
parallel port is tied to the limit lines. Not good. The data out optos
will be supplied by the PC 5V supply. Yes, I know this means more than just a single cable from the PC - another argument for making the board fit into
a PCI/ISA slot.
Doug
-----Original Message-----
From: Dean Sala [SMTP:adsala@...]
Sent: Friday, February 25, 2000 8:25 PM
To: CAD_CAM_EDM_DRO@...
Subject: [CAD_CAM_EDM_DRO] Wonderboard PC interface original message!
From: "Dean Sala" <adsala@...>
It seems as though this thread has went off on a tangent. I originally
replied to Doug about a parrallel interface card that I had designed to
work with CNCpro. But it seemed to never appear on the message board
except in Doug's reply to it. The reply is in the "Interface Update"
thread. Anyway, It seems as though some of you are getting confused
between what Doug is proposing and what I have done. So I want to clarify. I designed an proto typed external interface card to work with CNCpro. I
am building a homebrew CNC system so my design is catered towards that. I
believe Doug has different requirements and is building a more robust
board catered towards industrial use. Am I right? I'm not completely
clear about his requirements yet. But this is what I wrote to him.
Here is my original message to the "Interface update" thread.
-------------------------------------------------------------------------
- ----------------------------------------------------
Doug,
It's real great that you are trying to resolve this problem. I
completely agree that we need some sort of breakout box that could get us up to
speed faster. With an on board 5vPS, relays, screw in terminals and such. It
just so happens that I have already designed a proto type of this board
to work with CNCpro. Except that it does not use optoisolation on the
board.
I already have optoisolation on board my step drivers.
The proto type plugs into the parrallel port via cable. It has it's own
DB25 connector on one side and has a series of screw terminals on the
other.
It consists of a SN74S244 hex schmit trigger driver to drive the step and
direction data (3 or 4 axis or whatever)into the Step motor drivers. The
auxillary outputs, 3 in all so far (CNCPro at least) go through
ULN2003a's (that can be parralleled for more current) to drive 1amp 5v relays.
Also,
the homing inputs are hooked up to IR switches with their own terminal
block. The other inputs are just tied high through 4.7ks. I am still
working on the design and am thinking about making it more universal for
other parrallel port NC programs that aren't as configurable as CNCpro.
But
first I'm keeping it simple. I'm sorry for not getting ideas from you
guys
but now I have a feeling what you want. Are you sure you need
optoisolation
on the board too? I can add them right to the output of the SN74S244 but
then the opto isolators would be driving opto isolators. Maybe I can put
a
switch selector to bypass opto isolation if the step drivers have them.
Possible enhancements: On board 5V power supply(otherwise supply external
5v
PS). Connectors to connect 120v to stepper power supply with fuses etc.
Diagnostic LEDs connected to various outputs. Connectors for main power
switch and power light. Oh, limit switch connectors tied to turn off
stepper PS. There you have it! All-in-one wonder board!
About using the parrallel port for drive LED's....you should sink them of
course but it's always better to put a buffer inline like an S series TTL
driver which can source 28ma and sink 64ma perfect for this situation,
more
noise resistant and just what their made for. This way you don't have to
worry about how much power the parallel port can provide.
Good luck
Dean
-------------------------------------------------------------------------
- -------------------------------------------------------------
Please read Dougs reply in the "Interface Update" thread if you are
interested in his comments. It is a message stored under his name
If you have any questions about my design please reply. I left a few
things out of the above description.
Thanks
Dean Sala
------------------------------------------------------------------------
Shabang!com is the place to get your FREE eStore, Absolutely FREE
Forever. If you have any desires to sell your products or services
online, or you want to expand your customer base for FREE, Come check
out Shabang!com FREE eStores!
------------------------------------------------------------------------
Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
discussion of shop built systems in the above catagories.
To Unsubscribe, read archives, change to or from digest.
Go to:
Log on, and you will go to Member Center, and you can make changes there.
For the FAQ, go to
bill,
List Manager ------------------------------------------------------------------------
GET A NEXTCARD VISA, in 30 seconds! Get rates
as low as 0.0% Intro APR and no hidden fees.
Apply NOW!
------------------------------------------------------------------------
Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
discussion of shop built systems in the above catagories.
To Unsubscribe, read archives, change to or from digest.
Go to:
Log on, and you will go to Member Center, and you can make changes there.
For the FAQ, go to
bill,
List Manager
___________________________________________________________________________
____ ___________________________________________________________________________ ____
Message: 5
Date: Mon, 28 Feb 2000 14:45:41 -0700 (MST)
From: "D.F.S." <dfs@...>
Subject: Re: re - Wonderboard PC interface
From: "Harrison, Doug" <dharrison@...>
Yes, we did get a little carried away with this one. I did manage to get
plenty of feedback, so much that I printed it into a big stack of paper
(more trees died) and took it home to read over the weekend. Thanks to
all who contributed.
I still have some more research to do before I commit to the final
specification. Perhaps I should clarify my goals, which have not
changed. The plan was to design a board with enough dummyproofing to use in
industrial applications yet simple enough to be inexpensive and quick to
build. I see the potential to use this board as an interface with
several parallel port step motor programs. However, CNCPro is the one program I
feel comfortable enough with to support for retrofits. That is the
program I am designing the board for. This is not meant to be a negative comment
on other software and I would be happy to work with developers of such
programs if they wish to communicate their wants and needs. The info I have on
most of them is inadequate to work with.
Here is the design I threw together over the weekend.
It is not final, it is a starting point only.
There is some serious proofreading and checking to be done, but the basic
interface is all there.
I'm out of town this week.
I DO have the design and the free design package with me (Easy Trax)
The problem, is on my laptop, it can only run in 640X480 Mode and
That is only shown as about a 4" X 6" rectangle.
I'll be seriously limited in any REAL work on in.
I can generate Postscript files of the board.
I have no real way to generate an image given the current situation.
If anyone can convert it, and post is someplace everyone can see it.
let me know.
The preliminary specification looks like this:
1. Separate board - not in PC. ( I may change this again if I succeed
in solving the DC-DC converter issue. Shucks! I might even go both ways.) My board is external to allow lots of board space to add custom circuits.
2. All input and output lines optoisolated. My design will use opto-isolators on the Board to PC interface.
The Board to device interface should probably have them where
damage is likely to happen as well.
I'll need about 20, about 11 outbound and 9 inbound to the PC.
3. All optos socketed. I figured on socketing all the chips.
4. Selection of optos to allow interchangability between cheap and high
speed optos for step/direction lines. The 17 Cent parts BG Micro has looked plenty fast for anythink you will
ever be able to spit out of a PC.
5. Sockets for optional SS relays on control lines. I have PC mount Simgle pole Double throw Relays I planned to use.
I don't have sockets for them, but leaving holes for them along with
a big array of space to install them and wire them where appropriate
seems reasonable.
What do you mean by "SS" relay?
6. On board 5V power. I figure the power and voltage requirements could vary tremendously
depending on what a person wanted to install as far as external
drive and interfaces.
110 or 220V are very likely to be used by some people.
I figured on running AC straight to the box, and installing a
surplus regulated power supply in the box, to leave all the options
open.
BG Micro, all electronics amd electronics goldmine all have a
good selection of regulated power supplies for under 10 bucks,
many are universal and can take anything from 90 - 250 Volts.
7. DB25 and screw term capable input - your choice Mine has a 2 row 26 pin connector to the computer.
I have both 25 pin Din and 26 pin header connectors that simply crimp
on ribon cable.
Cut the cable to length and crimp the ends on.
Of course everyone has the option to crimp whatever type of connector
they want on the other end, even if it only extends to a connector
mounted on the outside of the case.
For the IO ports, I suggest dual connectors designed onto the board
and people can install the type they want. Ie. a standard header, and
holes to mount whatever readily avalible type of screw connector
we select.
I DO have some, but they are big, they take crim on spade type
connectors. There are 3 lugs on each pin, they are held down
by a screw, you could always remove the screw, toss the spades and
connect the wire to the screw.
8. DB9 and screw term options for step/dir lines. Good idea, both designed onto the board, install whatever you want.
9. Screw terms for limits, e-stop and control outs. Same as above.
Several of you noted that it should not be necessary to use optos to
drive the step/dir amp inputs because most drivers are already optoisolated.
Some of them aren't. But the main reason I stuck to my guns here is that
there is a tendency (and I've seen it) to use the same 5V supply for the driver
optos as is used for the limit switches. The drivers are protected but
the parallel port is tied to the limit lines. Not good. The data out optos
will be supplied by the PC 5V supply. Yes, I know this means more than
just a single cable from the PC - another argument for making the board fit
into a PCI/ISA slot. My design would isolate all the PC lines at the point the enter from
and exit to the PC. That should protect the PC.
People could then isolate whatever IO From they board they considered
necessart to protect the "Wonderboard".
I would just as soon keep the board outside of the PC case.
The ISA board will now work with Laptops, Microchannel PCs and many
people would be afraid to install it inside the case anyway.
All the Status and Diagnostic LEDs I have designed in, are mounted
on the board itself. They would need to be run outside the PC and be
mounted in a project case of some sort.
Marc
BTW. we are still under 10 bucks in parts.
Granted, additions will add to that cost, but the basic board is under
10, plus a power supply, and whatever case people want.
___________________________________________________________________________
____ ___________________________________________________________________________ ____
Message: 6
Date: Mon, 28 Feb 2000 23:56:43 -0000
From: "Terry May" <tmay@...>
Subject: RE: DRO UPDATE
Art,
Just wanted to tell I have been looking at your website, great
pictures!! It really helps to visualize your setup as you have been
discribing it on the list. I hope my DRO turns out to be half as good
as yours.
Just a quick update from my shop, I didn't have any 7414's or the
decrete transistors that Steve Linsay used on my bench so I just
played around a bit. Hooked up the encoders to my scope and checked
out the waveform and then used a freq counter to do the same. All the
encoders look like they are working fine so after work tomorrow I
will pickup some chips at Radio Shack and put together a board.
Concerning the discussions about wires/cables for the setup, I have
lots of good parts left over from a dearly departed HP plotter.
Amoung the goodies are all the wires used to move the pen holder, I
think they will be long enough for the Y and Z axis' of my mill/drill
if not the x axis.
As I was playing with the encoder still hooked to the motor and
reading it with the freq counter, I realized that just one channel
out of a 1000 line encoder is a very nice division factor for a
tach????. I think I will experiment with that a little also.
Thanks again for sharing your experiences and your website!
Terry May
___________________________________________________________________________
____ ___________________________________________________________________________ ____
Message: 7
Date: Mon, 28 Feb 2000 18:59:48 -0500
From: Charles Gallo <Charlie@...>
Subject: Feedback wanted
Hi,
I was just wondering is anyone has gotten a chance to look at Stepster
Build 11?
Charlie
-->
RKBA!
PGP Fingerprint: 7218 67D7 54B8 EFAF 67B7 4FED 7AC5 3687 492C 7382
PGP Key at
___________________________________________________________________________
____ ___________________________________________________________________________ ____
Message: 8
Date: Mon, 28 Feb 2000 19:31:06 -0500
From: "A. G. Eckstein" <axtein@...>
Subject: Re: RE: DRO UPDATE
Terry,
Thanks for the words of encouragement. I need that and hope my little bit
will help. I appreciate all the words that I have gotten on the site and as
things progress, will try to update it. My long term goal is to get to the
magical resolution of 0.0001"
Actually, when I started the goal was to get accuracy to 0.001" with no
backlash. I have far exceeded that but now it is a challange.
Please let me know if I can help further.
Art
At 11:56 PM 02/28/2000 -0000, you wrote:
From: "Terry May" <tmay@...>
Art,
Just wanted to tell I have been looking at your website, great
pictures!! It really helps to visualize your setup as you have been
discribing it on the list. I hope my DRO turns out to be half as good
as yours.
Just a quick update from my shop, I didn't have any 7414's or the
decrete transistors that Steve Linsay used on my bench so I just
played around a bit. Hooked up the encoders to my scope and checked
out the waveform and then used a freq counter to do the same. All the
encoders look like they are working fine so after work tomorrow I
will pickup some chips at Radio Shack and put together a board.
Concerning the discussions about wires/cables for the setup, I have
lots of good parts left over from a dearly departed HP plotter.
Amoung the goodies are all the wires used to move the pen holder, I
think they will be long enough for the Y and Z axis' of my mill/drill
if not the x axis.
As I was playing with the encoder still hooked to the motor and
reading it with the freq counter, I realized that just one channel
out of a 1000 line encoder is a very nice division factor for a
tach????. I think I will experiment with that a little also.
Thanks again for sharing your experiences and your website!
Terry May OLDER THAN DIRT
Country Bubba
(Actually the inventor of Country and Bubba)
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Message: 9
Date: Mon, 28 Feb 2000 20:53:13 -0500
From: Charles Hopkins <chopkins@...>
Subject: DRO
Can someone point me to Tom Kulaga's DRO application program?
Thanks
Charles Hopkins
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Message: 10
Date: Mon, 28 Feb 2000 19:09:58 -0700
From: "Tim Goldstein" <timg@...>
Subject: Re: DRO
Try
Tim
[Denver, CO]
Can someone point me to Tom Kulaga's DRO application program?
Thanks
Charles Hopkins
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Message: 11
Date: Mon, 28 Feb 2000 22:13:20 -0500
From: "Jim Geib" <jimg47@...>
Subject: Re: DRO
This is the link to Tom's page that I have.
Jim Geib
Mansfield, Ohio
----- Original Message -----
From: "Charles Hopkins" <chopkins@...>
To: <CAD_CAM_EDM_DRO@...>
Sent: Monday, February 28, 2000 8:53 PM
Subject: [CAD_CAM_EDM_DRO] DRO
From: Charles Hopkins <chopkins@...>
Can someone point me to Tom Kulaga's DRO application program?
Thanks
Charles Hopkins
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Message: 12
Date: Mon, 28 Feb 2000 22:27:55 -0500
From: "Multi-Volti Devices" <multi-volti@...>
Subject: For sale: two used Superior Electric 840 oz-in steppers
Hello:
In my quest for the mother-of-all-steppers (haven't found any NEMA 66, had
to settle for a NEMA 42), I found a seller who will only sell three motors.
I only want one (sound familiar?), but he won't sell me just one because he
anticipates most machine users want three axis capability.
He says the 840 oz-in motors are used, not new. $225 each plus shipping. I
guess the simplest thing is for me to buy all three, so someone doesn't
skunk me by buying all three.
Anyone need two hefty motors so I can buy the third?
Murray
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Message: 13
Date: Tue, 29 Feb 2000 04:21:12 EST
From: ptengin@...
Subject: Re: re - Wonderboard PC interface
In a message dated 02/28/2000 11:50:07 AM Hawaiian Standard Time,
dfs@... writes:
<< DB25 and screw term capable input >>
I believe Doug was speaking of the euro screw terminals.
Peter
THRD, Inc.
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Message: 14
Date: Tue, 29 Feb 2000 04:26:17 EST
From: ptengin@...
Subject: Re: For sale: two used Superior Electric 840 oz-in steppers
In a message dated 02/28/2000 5:30:12 PM Hawaiian Standard Time,
multi-volti@... writes:
<< I found a seller who will only sell three motors.
I only want one (sound familiar?), but he won't sell me just one <snip>
Anyone need two hefty motors so I can buy the third?
Murray >>
Murray,
If you ever go "Belly up" with that one motor, you will be out of luck
finding one at your local Rat Shack. You might get rid of one but I would
not get rid of two.....
IMHO
Peter
THRD, Inc.
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Message: 15
Date: Tue, 29 Feb 2000 10:57:17 -0000
From: "Peter Smith" <peter@...>
Subject: Re: is my software stable?
----- Original Message -----
From: Joe Vicars <jvicars@...>
To: <CAD_CAM_EDM_DRO@...>
Sent: 25 February 2000 20:31
Subject: [CAD_CAM_EDM_DRO] is my software stable?
Hello Joe
I to have just started using DeskNC and G codes, and noticed an odd effect
with the programing, in the two examples below, the first one does not run
correctly, i.e. when the motors are decelerating almost to a stop, there
seems to be a kick just as the motor stops ( all axis, lost steps), this
does not happen in the second one where G90 X0.0 Y0.0 Z0.0 are on the same
line, I have also noticed that comments in the file sometimes cause a
similar problem.
Has anyone had this problem before ?
G90
G00 X 0.0 Y0.0 Z0.0
G00 X1.8 Y1.8 Z-1.8
G00 X0.0 Y0.0 Z0.0
M02
G90 X0.0 Y0.0 Z0.0
G00 X1.8 Y1.8 Z-1.8
G00 X0.0 Y0.0 Z0.0
M02
Best Wishes
Peter Smith
From: Joe Vicars <jvicars@...>
I am running desknc from a 486 DOS only machine. So far everything
works great, but the longest program I have run is less than 30 seconds
total. Eventually I want to run more complicated paths, and much longer
execute times. Am I going to run into stability problems from the
software?
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Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the discussion of shop built systems in the above catagories.
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Go to:
Log on, and you will go to Member Center, and you can make changes there.
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