Called AMC and as always, talked to a great guy.

Just wanted to post this summary so as to make it available to anyone
looking for same.

Pot 1, Loop Gain, is the one responsible for responsiveness of the
motor to error in commanded parameter (speed in my case, as I run in
velocity mode). To adjust it, turn it clockwise until the motor starts
vibrating when commanded zero. Then back out 1-2 turns. Gunner pretty
much said the same thing.

Pot 3, Reference Gain, has nothing to do with stability of the servo
system and represents only the proportion of how much speed you get
for a given volts input. Fully clockwise it means 100% available
speed.

I will make some adjustments tonight based on that, so as to get a
stable system operating at top performance. During tuning, I turned
down Ref gain, for no good reason as it turns out. So my motors do not
operate at top speed avaliable from the drive.

i

On Jul 23, 3:47*pm, Ignoramus7608
wrote:
Called AMC and as always, talked to a great guy.

It sure is refreshing when the support people actually provide some
support.

This is all very good news - that the adjustments appear so easy to
accomplish. Not that I'm not interested in Karl & Tim's more
scientific approach - I've designed a few controllers over the years
and this is STILL interesting stuff, but it's nice to see that
Gunner's more nuts & bolts method will get you close enough*. But
what do the other pots do (there are five, if I remember correctly)?


* Wouldn't it be great if Gunner could just stick to what he knows?

On 07/23/2010 12:47 PM, Ignoramus7608 wrote:
Called AMC and as always, talked to a great guy.

Just wanted to post this summary so as to make it available to anyone
looking for same.

Pot 1, Loop Gain, is the one responsible for responsiveness of the
motor to error in commanded parameter (speed in my case, as I run in
velocity mode). To adjust it, turn it clockwise until the motor starts
vibrating when commanded zero. Then back out 1-2 turns. Gunner pretty
much said the same thing.

Ha! That's what I figured.

Pot 3, Reference Gain, has nothing to do with stability of the servo
system and represents only the proportion of how much speed you get
for a given volts input. Fully clockwise it means 100% available
speed.

Well....

It has nothing to do with the stability of the _drive_, but it affects
the overall gain of the position servo. When you change the setting on
that pot it'll change the gain that EMC 'sees'. Turning up the gain on
that pot has the same effect as turning up all the gains in EMC.

So, set it such that the voltage range of the drive, without topping out
in speed, matches the voltage range that EMC will send. Then don't ever
touch it -- putting inspection paint on it to seal it would not be a bad
idea, or even a drop of beeswax.

I will make some adjustments tonight based on that, so as to get a
stable system operating at top performance. During tuning, I turned
down Ref gain, for no good reason as it turns out. So my motors do not
operate at top speed avaliable from the drive.

i


--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Fri, 23 Jul 2010 14:47:43 -0500, Ignoramus7608
wrote:

Called AMC and as always, talked to a great guy.

Just wanted to post this summary so as to make it available to anyone
looking for same.

Pot 1, Loop Gain, is the one responsible for responsiveness of the
motor to error in commanded parameter (speed in my case, as I run in
velocity mode). To adjust it, turn it clockwise until the motor starts
vibrating when commanded zero. Then back out 1-2 turns. Gunner pretty
much said the same thing.

Pot 3, Reference Gain, has nothing to do with stability of the servo
system and represents only the proportion of how much speed you get
for a given volts input. Fully clockwise it means 100% available
speed.

I will make some adjustments tonight based on that, so as to get a
stable system operating at top performance. During tuning, I turned
down Ref gain, for no good reason as it turns out. So my motors do not
operate at top speed avaliable from the drive.

i

Did they tell you how to adjust Test Offsets?
Very critical for proper and clean movements.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On Fri, 23 Jul 2010 13:05:45 -0700, Tim Wescott
wrote:

On 07/23/2010 12:47 PM, Ignoramus7608 wrote:
Called AMC and as always, talked to a great guy.

Just wanted to post this summary so as to make it available to anyone
looking for same.

Pot 1, Loop Gain, is the one responsible for responsiveness of the
motor to error in commanded parameter (speed in my case, as I run in
velocity mode). To adjust it, turn it clockwise until the motor starts
vibrating when commanded zero. Then back out 1-2 turns. Gunner pretty
much said the same thing.

Ha! That's what I figured.

Pot 3, Reference Gain, has nothing to do with stability of the servo
system and represents only the proportion of how much speed you get
for a given volts input. Fully clockwise it means 100% available
speed.

Well....

It has nothing to do with the stability of the _drive_, but it affects
the overall gain of the position servo. When you change the setting on
that pot it'll change the gain that EMC 'sees'. Turning up the gain on
that pot has the same effect as turning up all the gains in EMC.

So, set it such that the voltage range of the drive, without topping out
in speed, matches the voltage range that EMC will send. Then don't ever
touch it -- putting inspection paint on it to seal it would not be a bad
idea, or even a drop of beeswax.

Thats not really necessary..and he WILL need to retune it in about 2 yrs
after the electronics have aged a smidge. Well..at least in less than 4
yrs.

And its very "voltage" responsive...IE..if the voltage you feed the
electronics changes...so will the outputs. I see clients moving a
machine from one side of the factory to the other..or to another
site..one site may be 224volts..the other may be 245volts..and it
does..does change things. Still runs fine..but may run slower, or with
less accuracy.

Gunner


I will make some adjustments tonight based on that, so as to get a
stable system operating at top performance. During tuning, I turned
down Ref gain, for no good reason as it turns out. So my motors do not
operate at top speed avaliable from the drive.

i

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

Did they tell you how to adjust Test Offsets?
Very critical for proper and clean movements.

Gunner

You seem very knowledgeable here. I've turned it till it drifts left, then
turned it till it drifts right. Split the difference. Is this correct?

BTW, I have a Z servo that will vibrate on occasion. Used to be only once in
a great while, now once out of ten jogs. I just give it a nudge to stop.
But, I need to retune this, someday; when I get one of those round tuits.

Karl

On 2010-07-23, Gunner Asch wrote:
On Fri, 23 Jul 2010 14:47:43 -0500, Ignoramus7608
wrote:

Called AMC and as always, talked to a great guy.

Just wanted to post this summary so as to make it available to anyone
looking for same.

Pot 1, Loop Gain, is the one responsible for responsiveness of the
motor to error in commanded parameter (speed in my case, as I run in
velocity mode). To adjust it, turn it clockwise until the motor starts
vibrating when commanded zero. Then back out 1-2 turns. Gunner pretty
much said the same thing.

Pot 3, Reference Gain, has nothing to do with stability of the servo
system and represents only the proportion of how much speed you get
for a given volts input. Fully clockwise it means 100% available
speed.

I will make some adjustments tonight based on that, so as to get a
stable system operating at top performance. During tuning, I turned
down Ref gain, for no good reason as it turns out. So my motors do not
operate at top speed avaliable from the drive.

i

Did they tell you how to adjust Test Offsets?
Very critical for proper and clean movements.

They did not tell me that, but I would ilke to know!

i

On Fri, 23 Jul 2010 18:49:48 -0500, "Karl Townsend"
wrote:


Did they tell you how to adjust Test Offsets?
Very critical for proper and clean movements.

Gunner

You seem very knowledgeable here. I've turned it till it drifts left, then
turned it till it drifts right. Split the difference. Is this correct?

Correct in theory. Put a volt meter on...hummm 3 and 4 (pins on the
header connector) and set the last pot on the right... for IRRC...Zero
Volts. As you jog in opposite directions...it will go +/-,,,,but it
should go to the same voltage ..just plus/minus

The OmniTurn has a screen that shows both test offset and following
error that allows one to tweak the amps while watching the screen.

Im so used to using that screen..Im having a stroke moment trying to
remember the method without the screen.


BTW, I have a Z servo that will vibrate on occasion. Used to be only once in
a great while, now once out of ten jogs. I just give it a nudge to stop.
But, I need to retune this, someday; when I get one of those round tuits.

Back off the far left gain pot a couple turns and see what it does.

Here is the owners manual for most of the early versions..

http://omniturnfactorydirect.com/Omn..._G3_100128.pdf

Download it and go to section 6 and check the data for the AMC amps and
tuning. It may be of some assistance.


Gunner



Karl




One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

....
Here is the owners manual for most of the early versions..

http://omniturnfactorydirect.com/Omn..._G3_100128.pdf

Download it and go to section 6 and check the data for the AMC amps and
tuning. It may be of some assistance.


Gunner

Say, i scanned the gcode section trying to get to section 6. Omniturn has a
great write up here. Much better than the fanuc yellow manual I go by. Of
course, some Gcodes are different so i can't just copy it.

Karl

On Sat, 24 Jul 2010 09:31:30 -0500, "Karl Townsend"
wrote:

...
Here is the owners manual for most of the early versions..

http://omniturnfactorydirect.com/Omn..._G3_100128.pdf

Download it and go to section 6 and check the data for the AMC amps and
tuning. It may be of some assistance.


Gunner

Say, i scanned the gcode section trying to get to section 6. Omniturn has a
great write up here. Much better than the fanuc yellow manual I go by. Of
course, some Gcodes are different so i can't just copy it.

Karl


Ayup..each manufacture has different Gcodes, particularly canned cycles
and whatnot, but some of the stuff is pretty much common. Mike did a
very good job trying to make sure end users understood what was going
on, and why.

I had a small hand in some of the manual as well..but very small.

I had a slightly larger hand in writing some of these....

http://www.omni-turn.com/Pages/Techn...rt%20page.html

Stuff like this....

http://www.omni-turn.com/Pages/Techn...djustment.html

http://www.omni-turn.com/Pages/Techn...%20Tuning.html

http://www.omni-turn.com/Media/PDFs/...edure%20LR.pdf

And a fair number of the other stuff....shrug


One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

Oh..and this one may be of some interest..while not directly applicable
to a mill...there are some things one can do if something "isnt right"

http://www.omni-turn.com/Pages/Techn...%20issues.html


Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On Sat, 24 Jul 2010 11:17:04 -0700, Gunner Asch
wrote:



Oh..and this one may be of some interest..while not directly applicable
to a mill...there are some things one can do if something "isnt right"

http://www.omni-turn.com/Pages/Techn...%20issues.html


Gunner


And I see they posted the new Generation 4 manual..which is mostly
backwardly compatable with most of the older machines.

EXCEPT for older Servo Amps..it only covers the OmniTurn/Glentek
servos. Damn..why the hell...never mind.....

http://omniturnfactorydirect.com/Omn..._G4_100611.pdf


Check out the G code listing on page...hummm 1.22 or somewhere about
there.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch