On Friday, October 21, 2011 09:31:58 PM Jon Elson did opine:
gene heskett wrote:
With only the encoders plugged into the PPMC boards the D-sub
connector does not show ground.
OK let make sure I am saying this right with only the encoder
plugged in and my meter set to ohms, one lead on
On Friday, October 21, 2011 09:44:51 PM Peter Blodow did opine:
gene heskett schrieb:
I would certainly try it. I have had no problems, but that is how I
have always done it. With my 60 years of chasing electrons for a
living, that is a lesson I learned about the first time I ever built
Bruce Klawiter wrote:
Well I hope it is solved and I don't even know how I did it.
OHHHhhh NOOo! That's the worst kind, as it can come BACK!
I know, I spent the rest of the day trying to get the twitching to come
back so I would know what the problem was, but I can't.
gene heskett wrote:
With only the encoders plugged into the PPMC boards the D-sub
connector does not show ground.
OK let make sure I am saying this right with only the encoder
plugged in and my meter set to ohms, one lead on the D-sub
connector and on on the chassis it shows an open circuit.
gene heskett schrieb:
I would certainly try it. I have had no problems, but that is how I have
always done it. With my 60 years of chasing electrons for a living, that
is a lesson I learned about the first time I ever built an audio amplifier
at about 15 YO. A Williamson circuit, using
Bruce Klawiter wrote:
I must have not have been very clear on that, what I said or
meant to say is, I disconnected the Z and Y axis from the
DAC and disconnected all the connectors from the Y and Z
amps. With the Y and Z axis disconnected the X axis still twitches.
I have disconnected
Problem solved.
Well I hope it is solved and I don't even know how I did it. Here is what I did
today,
Jon said You may be able to use the AC range on a DVM, and check while the
machine is moving, that might have an effect. The AC range of the meter should
show just about zero, anything
Bruce Klawiter wrote:
Problem solved.
Well I hope it is solved and I don't even know how I did it.
OHHHhhh NOOo! That's the worst kind, as it can come BACK!
Here is what I did today,
Jon said You may be able to use the AC range on a DVM, and check while the
machine is moving, that
Well I hope it is solved and I don't even know how I did it.
OHHHhhh NOOo! That's the worst kind, as it can come BACK!
I know, I spent the rest of the day trying to get the twitching to come
back so I would know what the problem was, but I can't.
Well, this is NOT OK! .1 V AC on the
Problem solved.
Well I hope it is solved and I don't even know how I did it. Here is what I did
today,
Jon said You may be able to use the AC range on a DVM, and check while the
machine is moving, that might have an effect. The AC range of the meter should
show just about zero, anything
On Monday, October 17, 2011 11:46:15 PM Bruce Klawiter did opine:
Well I hope it is solved and I don't even know how I did it.
OHHHhhh NOOo! That's the worst kind, as it can come BACK!
I know, I spent the rest of the day trying to get the twitching to come
back so I would know what
On Sunday, October 16, 2011 07:35:11 AM Bruce Klawiter did opine:
Yup, that is a concern. The fact that his Z axis appears to have
abnormal transients even when disconnected from any command input at
the same time the X has similar transients seems to indicate a ground
loop **IS** to blame
My understanding from a message about a week ago was that
you had disconnected the DAC board from the Z axis amp, and
still saw a twitch on the Z at the same time as the X twitched.
I must have not have been very clear on that, what I said or meant to say is,
I disconnected the Z and Y
Bruce Klawiter wrote:
My understanding from a message about a week ago was that
you had disconnected the DAC board from the Z axis amp, and
still saw a twitch on the Z at the same time as the X twitched.
I must have not have been very clear on that, what I said or meant to say
I must have not have been very clear on that, what I said or
meant to say is, I disconnected the Z and Y axis from the
DAC and disconnected all the connectors from the Y and Z
amps. With the Y and Z axis disconnected the X axis still twitches.
I have disconnected the X axis and the Y and Z
Trying to get rid of spikes, see image 8 here:
https://sites.google.com/site/bmklawt/home/pid-tuning
See the jitter here: http://www.youtube.com/user/bmklawt
Probably not the root cause of the problem, but you might try commenting
out all the backlash statements in your ini file.
Tried
On Saturday, October 15, 2011 12:12:40 PM Bruce Klawiter did opine:
Trying to get rid of spikes, see image 8 here:
https://sites.google.com/site/bmklawt/home/pid-tuning
See the jitter here: http://www.youtube.com/user/bmklawt
Probably not the root cause of the problem, but you might try
Here is our ground wiring.. (lower left hand corner of box. - yes it is messy)
http://electronicsam.com/images/KandT/conversion/groundwiring.jpg
sam
On Sat, 15 Oct 2011 12:21:01 -0400
gene heskett ghesk...@wdtv.com wrote:
On Saturday, October 15, 2011 12:12:40 PM Bruce Klawiter did opine:
On Saturday, October 15, 2011 01:43:50 PM sa...@empirescreen.com did opine:
Here is our ground wiring.. (lower left hand corner of box. - yes it is
messy)
http://electronicsam.com/images/KandT/conversion/groundwiring.jpg
sam
I've done worse myself that worked ok.
The long bus bar does
On Sat, 15 Oct 2011 14:00:54 -0400
gene heskett ghesk...@wdtv.com wrote:
On Saturday, October 15, 2011 01:43:50 PM sa...@empirescreen.com did opine:
Here is our ground wiring.. (lower left hand corner of box. - yes it is
messy)
Bruce Klawiter wrote:
Trying to get rid of spikes, see image 8 here:
https://sites.google.com/site/bmklawt/home/pid-tuning
you need to check the + and - 15 Volts, or whatever the servo amps use
as the supply for their op-amps. Capacitors may have
deteriorated and there is
Yup, that is a concern. The fact that his Z axis appears to have
abnormal transients even when disconnected from any command input at the same
time the X has similar transients seems to indicate a ground loop **IS** to
blame for this. There should be NO WAY that two amplifiers should have
Jon Elson elson@... writes:
Yeah, actually, I'd like to see one of these spikes zoomed in on the
time scale so it is
See image 9 here: https://sites.google.com/site/bmklawt/home/pid-tuning
Bruce says he has run it back
and forth for
a half hour, and it was within one encoder count of
I have only lightly been following this thread. I have some experience
converting a large hmc and initially not knowing how to hook up the
+/-10 volt signals from the mesa hardware. Initially testing I sure
hooked it up wrong. The servos would spit and sputter when outputting a
constant
On 10/8/2011 5:08 PM, gene heskett wrote:
story deleted
Because, as the above story amply demo's, they live among us, and they
even breed! Cheers, Gene
When discussing a story like this, my son once said, Have you met the
average person? And fifty percent of people are dumber than that.
On Sunday, October 09, 2011 10:00:38 AM Bruce Klawiter did opine:
Jon Elson elson@... writes:
Yeah, actually, I'd like to see one of these spikes zoomed in on the
time scale so it is
See image 9 here: https://sites.google.com/site/bmklawt/home/pid-tuning
Bruce says he has run it back
On Sunday, October 09, 2011 11:26:21 AM Kenneth Lerman did opine:
On 10/8/2011 5:08 PM, gene heskett wrote:
story deleted
Because, as the above story amply demo's, they live among us, and they
even breed! Cheers, Gene
When discussing a story like this, my son once said, Have you met
Bruce Klawiter wrote:
Jon Elson elson@... writes:
Yeah, actually, I'd like to see one of these spikes zoomed in on the
time scale so it is
See image 9 here: https://sites.google.com/site/bmklawt/home/pid-tuning
OK, this is clearly a real movement of the machine, not any sort
Bruce,
Going back to my collection of servo amp manuals, I find I have a
schematic of the input section of
a Westamp A651. It does not have an instrumentation amp on the command
input. So, polarity
of the signals is important. The command input SIG is on J1 Pin 2.
The signal common, for
On 10/08/2011 11:08 PM, Bruce Klawiter wrote:
I unhooked the Y and Z axis amps and only had the X axis plugged into the DAC
board and when running the X axis it still had random jerks.
If you'd like to do some tests for the DAC-to-amp connection, you might
try the following. Forgive me if
--- On Sun, 10/9/11, gene heskett ghesk...@wdtv.com wrote:
Now, this is a small clue. And I would read that as meaning that
somewhere, it appears the ground connection from the D/A might be sharing a
path with some motor current. A ground loop maybe that defeats the
intention of the star
Karl Cunningham wrote:
On 10/08/2011 11:08 PM, Bruce Klawiter wrote:
I unhooked the Y and Z axis amps and only had the X axis plugged into the
DAC board and when running the X axis it still had random jerks.
If you'd like to do some tests for the DAC-to-amp connection, you might
On Sun, 9 Oct 2011 12:16:40 -0700 (PDT), you wrote:
--- On Sun, 10/9/11, gene heskett ghesk...@wdtv.com wrote:
Now, this is a small clue. And I would read that as meaning that
somewhere, it appears the ground connection from the D/A might be sharing a
path with some motor current. A
On 10 October 2011 01:17, Steve Blackmore st...@pilotltd.net wrote:
All the ground wires connect to a physical common point. The wires
radiate out like the points on a star :)
500 years after Copernicus, perhaps Octopus wiring is a better metaphor.
--
atp
Torque wrenches are for the
On 10/09/2011 12:22 PM, Jon Elson wrote:
On the Westamp A651, the SIG input just goes to a pot that goes to the
velocity error
amp summing junction. So, it should make little difference whether the
input is
open of shorted. I believe Bruce has run this test, I think with the
inputs open.
On Sunday, October 09, 2011 09:37:58 PM Bruce Klawiter did opine:
--- On Sun, 10/9/11, gene heskett ghesk...@wdtv.com wrote:
Now, this is a small clue. And I would read that as meaning that
somewhere, it appears the ground connection from the D/A might be
sharing a path with some motor
On Sunday, October 09, 2011 10:00:58 PM Steve Blackmore did opine:
On Sun, 9 Oct 2011 12:16:40 -0700 (PDT), you wrote:
--- On Sun, 10/9/11, gene heskett ghesk...@wdtv.com wrote:
Now, this is a small clue. And I would read that as meaning that
somewhere, it appears the ground connection from
On Sunday, October 09, 2011 10:02:09 PM andy pugh did opine:
On 10 October 2011 01:17, Steve Blackmore st...@pilotltd.net wrote:
All the ground wires connect to a physical common point. The wires
radiate out like the points on a star :)
500 years after Copernicus, perhaps Octopus wiring
--- On Sun, 10/9/11, gene heskett ghesk...@wdtv.com wrote:
The idea of a single point ground is just that, one common ground for the
whole system. However even the use of 'ground' in the sense that it is
connected to an earth ground, is generally not all that important. What is
important is
On Monday, October 10, 2011 12:34:15 AM Bruce Klawiter did opine:
--- On Sun, 10/9/11, gene heskett ghesk...@wdtv.com wrote:
The idea of a single point ground is just that, one common ground for
the whole system. However even the use of 'ground' in the sense that
it is connected to an earth
Bruce Klawiter wrote:
Sorry what I meant was .0005 between multiple parts
Sure, once you have it dialed in to the best click on the encoder, it should
repeat quite well, except for thermal expansion.
The machine did not dither or do the jerking with the old Anilam
control.Someone said the
On Fri, Oct 07, 2011 at 08:48:33PM -0700, Bruce Klawiter wrote:
The machine did not dither or do the jerking with the old Anilam
control.Someone said the axis might be drifting then snap back into
position, I put an indicator on an axis and it holds position and when
it jerks it moves about
On Saturday, October 08, 2011 04:42:00 PM Chris Radek did opine:
On Fri, Oct 07, 2011 at 08:48:33PM -0700, Bruce Klawiter wrote:
The machine did not dither or do the jerking with the old Anilam
control.Someone said the axis might be drifting then snap back into
position, I put an indicator
On 8 October 2011 22:08, gene heskett ghesk...@wdtv.com wrote:
And there weren't any wire nuts in sight, just twisted
together and taped.
I am amazed that you guys use wire nuts, they look so gimcrack
compared the the screw clamps that are mandatory here.
(This is a typical UK wiring junction
Chris Radek wrote:
On Fri, Oct 07, 2011 at 08:48:33PM -0700, Bruce Klawiter wrote:
The machine did not dither or do the jerking with the old Anilam
control.Someone said the axis might be drifting then snap back into
position, I put an indicator on an axis and it holds position and when
it
Andy,
I had the priviledge to learn home electrics at Muskegon High school in
1966 when I was an exchange student. I could have started a career as an
electrician right there but, even at my age of 17, I realized that there
must have been a lot more to electricity than what I had learned so
On Saturday, October 08, 2011 08:01:44 PM andy pugh did opine:
On 8 October 2011 22:08, gene heskett ghesk...@wdtv.com wrote:
And there weren't any wire nuts in sight, just twisted
together and taped.
I am amazed that you guys use wire nuts, they look so gimcrack
compared the the screw
gene heskett wrote:
Yikes! Perhaps marginally useful with stranded wire, but cold flow after 6
mo to a year would have me laying awake nights unless your locale has flat
outlawed alu wire.
Most countries were smart enough to have never IN-LAWED aluminum wire
is the smaller
sizes, and of
On 10/07/2011 08:48 PM, Bruce Klawiter wrote:
That sounds as good as it is going to get. Bruce
stated that the original machine couldhold .0005 tolerances on
parts. I find this hard to believe with an
encoder resolution of.0004. Maybe a good machinist could get it to
make consistent
parts
On Saturday, October 08, 2011 11:49:12 PM Jon Elson did opine:
gene heskett wrote:
Yikes! Perhaps marginally useful with stranded wire, but cold flow
after 6 mo to a year would have me laying awake nights unless your
locale has flat outlawed alu wire.
Most countries were smart enough
gene heskett wrote:
And when going after repairs, I have never been offered a thing with any
springs in it, just those little tubes of deoxit (sp?) grease to seal the
air out. If I ever have to do that again, I'll definitely ask.
They are not OBVIOUS springs, but the parts of the
Chris Radek chris@... writes:
I think I remember these are velocity mode with tachs
Yes they are
- forgive me for
not going back and checking the old messages - if so, set deadband to
zero, and try eliminating it by adjusting the offset pot on the amp.
What is the offset pot, on the
offset would be bal
On Fri, Oct 7, 2011 at 1:23 PM, Bruce Klawiter bmkl...@yahoo.com wrote:
Chris Radek chris@... writes:
I think I remember these are velocity mode with tachs
Yes they are
- forgive me for
not going back and checking the old messages - if so, set deadband to
zero,
On 7 October 2011 18:23, Bruce Klawiter bmkl...@yahoo.com wrote:
What is the offset pot, on the amp, I only have SIG, TAC, TC, CLM and BAL
pots.
BAL sounds most likely.
--
atp
Torque wrenches are for the obedience of fools and the guidance of wise men
Bruce Klawiter wrote:
Chris Radek chris@... writes:
I think I remember these are velocity mode with tachs
Yes they are
- forgive me for
not going back and checking the old messages - if so, set deadband to
zero, and try eliminating it by adjusting the offset pot on the amp.
That sounds as good as it is going to get. Bruce
stated that the original machine could hold .0005 tolerances on parts. I
find this hard to believe with an
encoder resolution of .0004. Maybe a good machinist could get it to make
consistent
parts with some dimension held to +/- .0005, but it
On 10/07/2011 10:16 PM, emc-users-requ...@lists.sourceforge.net wrote:
SIG and TAC are attenuators for the velocity command input and the
tachometer input.
CLM is current limit. BAL is the zero offset. TC is most likely the
loop compensation
on either the torque loop or velocity loop.
I was
I have my servos tuned the best I can get them see IMAGES 5, 6 and 7 here:
https://sites.google.com/site/bmklawt/home/pid-tuning
If I add any D term the oscillation gets worse to violent.
I can not get rid of this dithering or ocsillation while the axes are at rest
See IMAGE 4
I also noticed
On Thu, Oct 06, 2011 at 07:31:39PM -0700, Bruce Klawiter wrote:
I can not get rid of this dithering or ocsillation while the axes are at rest
See IMAGE 4
I think what happens is you get within deadband, the output goes to
zero, the amp offset causes a certain drift in a certain direction
(same
Bruce: I don't know how the system appears to be
behaving, but your
error
of 20 - 30 um on the trace looks about as good as you'll get with
those
scales. That's within 2-3 encoder counts of commanded position.
The
problems I guess I was hoping would go away is the dithering or
On 29 September 2011 13:23, Bruce Klawiter bmkl...@yahoo.com wrote:
are some halscope images of the dithering and jerking:
https://sites.google.com/site/bmklawt/home/pid-tuning
A single-count deadband in the PID might help.
I am not sure if this is a good idea, but I wonder if a low-pass
Bruce Klawiter wrote:
The
problems I guess I was hoping would go away is the dithering or
oscillation
when the machine is at rest.
Yes, this is the universal problem with servos. There is no way for the
dithering to
be less than one encoder count. So, in your case, the resolution
andy pugh wrote:
A single-count deadband in the PID might help.
I am not sure if this is a good idea, but I wonder if a low-pass
filter on the encoder position would help?
This was discussed some time ago, the real problem is a low-pass filter
must cause delay, and that is bad in a servo
Are the velocity tachs still active, so that the drives are closing a
velocity loop, and EMC2 is commanding that velocity loop on the basis
of position error?
If that is the case, I wonder if EMC2 would work with only I and FF1?
(And if you think that you have a puzzle, I am currently
andy pugh wrote:
Are the velocity tachs still active, so that the drives are closing a
velocity loop, and EMC2 is commanding that velocity loop on the basis
of position error?
Yes, his tachs are connected to the analog servo amps.
If that is the case, I wonder if EMC2 would work with only
On 27 September 2011 05:41, Jon Elson el...@pico-systems.com wrote:
his CNC machine apparently was made by Anilam with that
scale, that is only 2540 counts/inch.
Didn't Anilam also use velocity tachs too?
--
atp
Torque wrenches are for the obedience of fools and the guidance of wise men
requirements to determine which type of system you
have. This will determine what EMC2 needs.
Jim
-Original Message-
From: andy pugh [mailto:bodge...@gmail.com]
Sent: Tuesday, September 27, 2011 4:12 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Need help with servo
andy pugh wrote:
On 27 September 2011 05:41, Jon Elson el...@pico-systems.com wrote:
his CNC machine apparently was made by Anilam with that
scale, that is only 2540 counts/inch.
Didn't Anilam also use velocity tachs too?
Yes, I'm pretty sure it is a traditional velocity servo
I do not have a clue how to tune my servos. I have been reading everything I
can find on the subject but its like it is written in some alien language that
I'll never understand.
What I have been doing so far is following this guide
Bruce Klawiter wrote:
I do not have a clue how to tune my servos. I have been reading everything I
can find on the subject but its like it is written in some alien language
that I'll never understand.
What I have been doing so far is following this guide
On Mon, 2011-09-26 at 15:50 -0700, Bruce Klawiter wrote:
I do not have a clue how to tune my servos. I have been reading everything I
can find on the subject but its like it is written in some alien language
that I'll never understand.
What I have been doing so far is following this guide
Kirk Wallace wrote:
There are others on this list much more qualified to comment, but there
might be a hint that your encoder has some noise. Here is one of my
HALscopes:
http://www.wallacecompany.com/cnc_lathe/HNC/emc2/pid_x-1b.png
His encoder is BOUND to have a lot of positional
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