Re: [Emc-users] more dc servo questions

[Gene Heskett]

On Sunday 19 September 2021 20:12:01 Chris Albertson wrote:

> Is the PID controller running on the PC under LCNC or is this an
> external PID controller you built?
>
The pid is the stock lcnc pid,

> What are the numbers, the loop period, motor speed and numer of
> encoder lines. and so on?

from the .ini file:
#
# Axis A
#
[AXIS_A]
MAX_VELOCITY= 30.000
MAX_ACCELERATION= 1500.00

[JOINT_3]
TYPE= ANGULAR
HOME= 0.0
HOME_SEQUENCE   = 3
HOME_SEARCH_VEL = 9.0
HOME_LATCH_VEL  = -1.0
HOME_FINAL_VEL  = 30
HOME_OFFSET = 4.498500
VOLATILE_HOME   = 1
FERROR  = 0.50
MIN_FERROR  = 0.25
MAX_VELOCITY= 30.000
MAX_ACCELERATION= 1500.00
P   = 6000
I   = 1.700
D   = 0.7500
FF0 = 0
FF1 = 21.5
FF2 = 0.55
BIAS= 0
DEADBAND= 0.00015
BACKLASH= .1
MAX_OUTPUT  = 900.
SERVO_SCALE = 666.7
PWMGEN_TYPE = 2

Loop period is stock, 1 kilohertz. I've tried up to 4k, but it didn't 
help
> I don't think the fact that there is a worm gear matters.  The
> problem, I bet is the large inertia of the system.

Thats my assessment too. Throw in a bit of worm friction and it stops, 
still spitting out .1% to 1% drive, not enough to actually entice it to 
move once stopped.

> Aside from proper tuning of the PID gains you could change the system
> to use a nested or "cascade" PID.  THis allows the velocity setpoint
> to be controlled by the position error
> see the section "cascade" in the wiki article
> https://en.wikipedia.org/wiki/PID_controller

I looked at that 6 months ago, and quickly got lost.

> I think you want a very fast loop i=for the inner PID.  LIkely it
> wouldbe in external hardwarelike a microcontroller or FPGA.   (does
> MESA do the PID algorithm in the FPGA?  It should.)

But it doesn't that I know of.

Thanks Chris.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] more dc servo questions

[Chris Albertson]

Is the PID controller running on the PC under LCNC or is this an external
PID controller you built?

What are the numbers, the loop period, motor speed and numer of encoder
lines. and so on?

I don't think the fact that there is a worm gear matters.  The problem, I
bet is the large inertia of the system.

Aside from proper tuning of the PID gains you could change the system to
use a nested or "cascade" PID.  THis allows the velocity setpoint to be
controlled by the position error
see the section "cascade" in the wiki article
https://en.wikipedia.org/wiki/PID_controller

I think you want a very fast loop i=for the inner PID.  LIkely it
wouldbe in external hardwarelike a microcontroller or FPGA.   (does MESA do
the PID algorithm in the FPGA?  It should.)



On Sun, Sep 19, 2021 at 3:39 PM Gene Heskett  wrote:

> Greetings all;
> As most of you know, I built a servo from scratch for a BS-1.
>
> But I am not at all happy with its performance.
> It is a motor with a worm output, driving the worm of the bs-1. And it
> has an A/B quad encoder in it.
>
> But I must rather severely limit its run speed because the PID doesn't
> see the null coming near fast enough to slow it and stop a couple
> arcseconds early. I can't allow it to use reverse to stop as the motor
> seems to be a near short circuit then, crowbarring the power supply,
> causing a 2 to 3 minute dead time for the 450 watt psu to cool, so I
> must limit its speed to disallow its use of reverse to accomplish the
> stop.  With 2 worms in series the scale for a 360 degree full turn is of
> coarse huge.  If it could be throttled to a gradual stop by anticipating
> the coming null, I could probably run it 2 to 4x faster for a cruising
> speed.
>
> So my question is, which of the pid inputs would if raised, better
> anticipate the approaching null, slowing it over the last 5 angular
> minutes of a turn, ideally to a stop within an arc-second of the command
> from the gcode?
>
> Thanks all.
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] more dc servo questions

[Gene Heskett]

Greetings all;
As most of you know, I built a servo from scratch for a BS-1.

But I am not at all happy with its performance.
It is a motor with a worm output, driving the worm of the bs-1. And it 
has an A/B quad encoder in it.

But I must rather severely limit its run speed because the PID doesn't 
see the null coming near fast enough to slow it and stop a couple 
arcseconds early. I can't allow it to use reverse to stop as the motor 
seems to be a near short circuit then, crowbarring the power supply, 
causing a 2 to 3 minute dead time for the 450 watt psu to cool, so I 
must limit its speed to disallow its use of reverse to accomplish the 
stop.  With 2 worms in series the scale for a 360 degree full turn is of 
coarse huge.  If it could be throttled to a gradual stop by anticipating 
the coming null, I could probably run it 2 to 4x faster for a cruising 
speed.

So my question is, which of the pid inputs would if raised, better 
anticipate the approaching null, slowing it over the last 5 angular 
minutes of a turn, ideally to a stop within an arc-second of the command 
from the gcode?

Thanks all.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] DC Servo issues

[John Dammeyer]

I find the pendant great for that.  The only issue has been with setting tool 
height as selecting and moving an axis with the pendant doesn't change the 
buttons on the AXIS screen.  So I sneak up to the right hight but perhaps X is 
still selected for the keyboard jog buttons.  Then I click on set tool height 
and instead it sets the X offset.  Makes things interesting.

Well motors have been swapped back.  CAM generated for new Y axis plate to hold 
the Bergerda Motor.  Might as well try and see if I can move the Y Axis system 
with that small Bergerda AC Servo.  It did fine on the X but never did try the 
Y.

John




> -Original Message-
> From: Sam Sokolik [mailto:samco...@gmail.com]
> Sent: September-19-21 1:30 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] DC Servo issues
> 
> Yes..  I agree.   Though my favorite thing to setup on a linuxcnc machine
> is an encoder wheel for jogging and overrides...   What I use the most is
> maximum velocity over ride..  allows you to sneak up on part...
> 
> On Sun, Sep 19, 2021, 2:53 PM John Dammeyer  wrote:
> 
> > Hi Sam,
> > I must admit there's a certain amount of fear every time I press the go
> > button for a CNC program.  Especially when I started mucking around with
> > tool #'s and offsets.   My hand now overs over ESTOP when I press start.
> > Watching a tool that appears too low scream over to the part held in the
> > vise at a G0 180 ipm is not for the faint of heart.
> >
> > But then the first time I apply power to a newly assembled power supply my
> > heart is also in my throat.  For one product, if the Pick and Place people
> > didn't use enough solder under the ground pad of the regulator chip (the
> > only ground connection too), it would fry and take out the 8 SMD power
> > transistors for the dual supply.  Very difficult to repair.
> >
> > On the servo side, the caps are 200V rated as are the 50A transistors so
> > theoretically I could run one with 115VAC as the 165VDC supply.   That
> > would certainly provide the force to drive more current into the motor
> > windings and create the speed desired.  With 105V the motor can reach 3000
> > RPM with a lighter load, otherwise it would never work on the X axis but
> > the torque might also just be on the edge during acceleration in one
> > direction and not the other.
> >
> > Or build up a small circuit so I can measure the instantaneous DC current
> > with the scope (don't have a current probe) and see how much current the
> > motors are really drawing.   Torque is Amps x Turns and if the voltage
> > isn't there to push the amps then following errors are likely.
> >
> > John
> >
> >
> >
> > > -Original Message-
> > > From: Sam Sokolik [mailto:samco...@gmail.com]
> > > Sent: September-19-21 12:11 PM
> > > To: Enhanced Machine Controller (EMC)
> > > Subject: Re: [Emc-users] DC Servo issues
> > >
> > > Lol..  I certainly love the electrics part more than the machining most
> > of
> > > the time...
> > >
> > > On Sun, Sep 19, 2021, 2:07 PM John Dammeyer 
> > wrote:
> > >
> > > > Hi Sam,
> > > > See below.
> > > > > From: Sam Sokolik [mailto:samco...@gmail.com]
> > > > >
> > > > > I have never used servo drives that close the loop..   I have always
> > had
> > > > > great luck with normal closed loop within linuxcnc.  (cheap used amc
> > > > > drives)
> > > > >
> > > > > (Actually - I take that back - I have used the stmbl drives. so far
> > only
> > > > > for a spindle..)
> > > > >
> > > > > This is of course using mesa analog interface hardware.
> > > > >
> > > > > The only time I had issues with encoder counting was when I thought I
> > > > could
> > > > > get by with single ended encoders going over 8 ft...
> > > > >
> > > > > Look at something like this..  2 counts per rev,  2 axis with
> > 4000?
> > > > > counts per rev...  (and the encoders came installed on the servo,
> > single
> > > > > ended and I think they are us-digital)
> > > > > If I was missing counts during these complicated sync moves - you
> > would
> > > > > certainly see it.
> > > > >
> > > > > https://www.youtube.com/watch?v=-4sKHBh6rDk
> > > > >
> > > > > (plus no 3rd party software to tune...)  - Granted you have the
> > drives
> > > > and
> > > > > are familiar with them - at what point do you give up?
> > > > >
> > > > > sam
> > > >
> > > > That's the question.  One possibility to try is to grab 110VAC line
> > > > voltage. Put a bridge and caps on it and drive that motor with more
> > than
> > > > the 105VDC power supply.  I'll have to check if my transistors are
> > rated
> > > > for the 165VDC rectified voltage and I really would rather have them be
> > > > 250V transitors.   And then there's the filters on the board too. The
> > UHU
> > > > circuit was originally for up to about 75V.  The HP_UHU came about for
> > > > higher voltage drives;  Just don't know if I built mine for more than
> > > > 125VDC although the circuit design parts are for 11A.
> > > >
> > > > I _have_ tried 

Re: [Emc-users] DC Servo issues

[Sam Sokolik]

Yes..  I agree.   Though my favorite thing to setup on a linuxcnc machine
is an encoder wheel for jogging and overrides...   What I use the most is
maximum velocity over ride..  allows you to sneak up on part...

On Sun, Sep 19, 2021, 2:53 PM John Dammeyer  wrote:

> Hi Sam,
> I must admit there's a certain amount of fear every time I press the go
> button for a CNC program.  Especially when I started mucking around with
> tool #'s and offsets.   My hand now overs over ESTOP when I press start.
> Watching a tool that appears too low scream over to the part held in the
> vise at a G0 180 ipm is not for the faint of heart.
>
> But then the first time I apply power to a newly assembled power supply my
> heart is also in my throat.  For one product, if the Pick and Place people
> didn't use enough solder under the ground pad of the regulator chip (the
> only ground connection too), it would fry and take out the 8 SMD power
> transistors for the dual supply.  Very difficult to repair.
>
> On the servo side, the caps are 200V rated as are the 50A transistors so
> theoretically I could run one with 115VAC as the 165VDC supply.   That
> would certainly provide the force to drive more current into the motor
> windings and create the speed desired.  With 105V the motor can reach 3000
> RPM with a lighter load, otherwise it would never work on the X axis but
> the torque might also just be on the edge during acceleration in one
> direction and not the other.
>
> Or build up a small circuit so I can measure the instantaneous DC current
> with the scope (don't have a current probe) and see how much current the
> motors are really drawing.   Torque is Amps x Turns and if the voltage
> isn't there to push the amps then following errors are likely.
>
> John
>
>
>
> > -Original Message-
> > From: Sam Sokolik [mailto:samco...@gmail.com]
> > Sent: September-19-21 12:11 PM
> > To: Enhanced Machine Controller (EMC)
> > Subject: Re: [Emc-users] DC Servo issues
> >
> > Lol..  I certainly love the electrics part more than the machining most
> of
> > the time...
> >
> > On Sun, Sep 19, 2021, 2:07 PM John Dammeyer 
> wrote:
> >
> > > Hi Sam,
> > > See below.
> > > > From: Sam Sokolik [mailto:samco...@gmail.com]
> > > >
> > > > I have never used servo drives that close the loop..   I have always
> had
> > > > great luck with normal closed loop within linuxcnc.  (cheap used amc
> > > > drives)
> > > >
> > > > (Actually - I take that back - I have used the stmbl drives. so far
> only
> > > > for a spindle..)
> > > >
> > > > This is of course using mesa analog interface hardware.
> > > >
> > > > The only time I had issues with encoder counting was when I thought I
> > > could
> > > > get by with single ended encoders going over 8 ft...
> > > >
> > > > Look at something like this..  2 counts per rev,  2 axis with
> 4000?
> > > > counts per rev...  (and the encoders came installed on the servo,
> single
> > > > ended and I think they are us-digital)
> > > > If I was missing counts during these complicated sync moves - you
> would
> > > > certainly see it.
> > > >
> > > > https://www.youtube.com/watch?v=-4sKHBh6rDk
> > > >
> > > > (plus no 3rd party software to tune...)  - Granted you have the
> drives
> > > and
> > > > are familiar with them - at what point do you give up?
> > > >
> > > > sam
> > >
> > > That's the question.  One possibility to try is to grab 110VAC line
> > > voltage. Put a bridge and caps on it and drive that motor with more
> than
> > > the 105VDC power supply.  I'll have to check if my transistors are
> rated
> > > for the 165VDC rectified voltage and I really would rather have them be
> > > 250V transitors.   And then there's the filters on the board too. The
> UHU
> > > circuit was originally for up to about 75V.  The HP_UHU came about for
> > > higher voltage drives;  Just don't know if I built mine for more than
> > > 125VDC although the circuit design parts are for 11A.
> > >
> > > I _have_ tried one these motors with the STMBL but could never get it
> > > tuned and support from the designers was inadequate to help me so I
> gave
> > > up.
> > >
> > > I'd rather be machining...
> > >
> > > John
> > >
> > >
> > >
> > > >
> > > > On Sun, Sep 19, 2021 at 12:59 PM John Dammeyer <
> jo...@autoartisans.com>
> > > > wrote:
> > > >
> > > > > Hi Rick,
> > > > > It may also have something to do with the DC Servo drive
> electronics.
> > > > > Although it's differential encoder signalling the design may have
> > > internal
> > > > > issues that are somewhat corrected by the Henk Olsson module.  I
> had
> > > both a
> > > > > small electrolytic and ceramic capacitors right by the US Digital
> > > encoders,
> > > > > which BTW, have been discontinued for a few years.  Perhaps that's
> why?
> > > > > Issues?
> > > > >
> > > > > I swapped the X and Y motor/encoder pair and sure enough the
> problem
> > > moved
> > > > > to the Y axis along with now only 120 IPM instead of 150 IPM.
> Above
> > > that I
> > > > > 

Re: [Emc-users] DC Servo issues

[John Dammeyer]

I have a shunt circuit on the 105VDC supply for that.   I could build up 
another one of those PC boards to do it for a higher voltage supply.  But is it 
all worth it for one motor that does not match the data sheet winding 
resistance and shows up with problems.

John

> -Original Message-
> From: John Figie [mailto:zephyr9...@gmail.com]
> Sent: September-19-21 12:14 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] DC Servo issues
> 
> John Figie
> 
> 
> On Sun, Sep 19, 2021 at 2:07 PM John Dammeyer 
> wrote:
> 
> >
> >
> > That's the question.  One possibility to try is to grab 110VAC line
> > voltage. Put a bridge and caps on it and drive that motor with more than
> > the 105VDC power supply.  I'll have to check if my transistors are rated
> > for the 165VDC rectified voltage and I really would rather have them be
> > 250V transitors.
> 
> 
> I think you will need the 250V transistors and also need to consider a
> shunt resistor and switch to keep the bus voltage from going too high when
> you rapidly decelerate a motor.
> 
> 
> > And then there's the filters on the board too. The UHU circuit was
> > originally for up to about 75V.  The HP_UHU came about for higher voltage
> > drives;  Just don't know if I built mine for more than 125VDC although the
> > circuit design parts are for 11A.
> >
> > I _have_ tried one these motors with the STMBL but could never get it
> > tuned and support from the designers was inadequate to help me so I gave
> > up.
> >
> > I'd rather be machining...
> >
> > John
> >
> >
> >
> 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] DC Servo issues

[John Dammeyer]

Hi Sam,
I must admit there's a certain amount of fear every time I press the go button 
for a CNC program.  Especially when I started mucking around with tool #'s and 
offsets.   My hand now overs over ESTOP when I press start.  Watching a tool 
that appears too low scream over to the part held in the vise at a G0 180 ipm 
is not for the faint of heart.

But then the first time I apply power to a newly assembled power supply my 
heart is also in my throat.  For one product, if the Pick and Place people 
didn't use enough solder under the ground pad of the regulator chip (the only 
ground connection too), it would fry and take out the 8 SMD power transistors 
for the dual supply.  Very difficult to repair.

On the servo side, the caps are 200V rated as are the 50A transistors so 
theoretically I could run one with 115VAC as the 165VDC supply.   That would 
certainly provide the force to drive more current into the motor windings and 
create the speed desired.  With 105V the motor can reach 3000 RPM with a 
lighter load, otherwise it would never work on the X axis but the torque might 
also just be on the edge during acceleration in one direction and not the other.

Or build up a small circuit so I can measure the instantaneous DC current with 
the scope (don't have a current probe) and see how much current the motors are 
really drawing.   Torque is Amps x Turns and if the voltage isn't there to push 
the amps then following errors are likely.

John



> -Original Message-
> From: Sam Sokolik [mailto:samco...@gmail.com]
> Sent: September-19-21 12:11 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] DC Servo issues
> 
> Lol..  I certainly love the electrics part more than the machining most of
> the time...
> 
> On Sun, Sep 19, 2021, 2:07 PM John Dammeyer  wrote:
> 
> > Hi Sam,
> > See below.
> > > From: Sam Sokolik [mailto:samco...@gmail.com]
> > >
> > > I have never used servo drives that close the loop..   I have always had
> > > great luck with normal closed loop within linuxcnc.  (cheap used amc
> > > drives)
> > >
> > > (Actually - I take that back - I have used the stmbl drives. so far only
> > > for a spindle..)
> > >
> > > This is of course using mesa analog interface hardware.
> > >
> > > The only time I had issues with encoder counting was when I thought I
> > could
> > > get by with single ended encoders going over 8 ft...
> > >
> > > Look at something like this..  2 counts per rev,  2 axis with 4000?
> > > counts per rev...  (and the encoders came installed on the servo, single
> > > ended and I think they are us-digital)
> > > If I was missing counts during these complicated sync moves - you would
> > > certainly see it.
> > >
> > > https://www.youtube.com/watch?v=-4sKHBh6rDk
> > >
> > > (plus no 3rd party software to tune...)  - Granted you have the drives
> > and
> > > are familiar with them - at what point do you give up?
> > >
> > > sam
> >
> > That's the question.  One possibility to try is to grab 110VAC line
> > voltage. Put a bridge and caps on it and drive that motor with more than
> > the 105VDC power supply.  I'll have to check if my transistors are rated
> > for the 165VDC rectified voltage and I really would rather have them be
> > 250V transitors.   And then there's the filters on the board too. The UHU
> > circuit was originally for up to about 75V.  The HP_UHU came about for
> > higher voltage drives;  Just don't know if I built mine for more than
> > 125VDC although the circuit design parts are for 11A.
> >
> > I _have_ tried one these motors with the STMBL but could never get it
> > tuned and support from the designers was inadequate to help me so I gave
> > up.
> >
> > I'd rather be machining...
> >
> > John
> >
> >
> >
> > >
> > > On Sun, Sep 19, 2021 at 12:59 PM John Dammeyer 
> > > wrote:
> > >
> > > > Hi Rick,
> > > > It may also have something to do with the DC Servo drive electronics.
> > > > Although it's differential encoder signalling the design may have
> > internal
> > > > issues that are somewhat corrected by the Henk Olsson module.  I had
> > both a
> > > > small electrolytic and ceramic capacitors right by the US Digital
> > encoders,
> > > > which BTW, have been discontinued for a few years.  Perhaps that's why?
> > > > Issues?
> > > >
> > > > I swapped the X and Y motor/encoder pair and sure enough the problem
> > moved
> > > > to the Y axis along with now only 120 IPM instead of 150 IPM.  Above
> > that I
> > > > get following errors.  Given that this motor has a higher winding
> > > > resistance I'm going to guess it's not a 90VDC motor but is more
> > likely a
> > > > 180VDC motor that was shipped as a 90VDC.   Maybe the loading
> > introduces
> > > > noise in one direction that fools the quadrature encoder.  It's very
> > > > strange that the following errors are only in one direction.
> > > >
> > > > At $145US plus shipping, since Automation Technologies won't replace
> > it,
> > > > I'm going to cast a new mounting plate 

Re: [Emc-users] DC Servo issues

[Rick Moscoloni]

Is really a pain to debug such issues, i have an old machine with the same
motors connected to gecko 340 (but I have to remove the multiplier), us
digital encoders wont work without the caps.
I hope you can resolve this issue soon, i pull my hair when things like
this show up!
Go John!

El dom, 19 sept 2021 a las 14:59, John Dammeyer ()
escribió:

> Hi Rick,
> It may also have something to do with the DC Servo drive electronics.
> Although it's differential encoder signalling the design may have internal
> issues that are somewhat corrected by the Henk Olsson module.  I had both a
> small electrolytic and ceramic capacitors right by the US Digital encoders,
> which BTW, have been discontinued for a few years.  Perhaps that's why?
> Issues?
>
> I swapped the X and Y motor/encoder pair and sure enough the problem moved
> to the Y axis along with now only 120 IPM instead of 150 IPM.  Above that I
> get following errors.  Given that this motor has a higher winding
> resistance I'm going to guess it's not a 90VDC motor but is more likely a
> 180VDC motor that was shipped as a 90VDC.   Maybe the loading introduces
> noise in one direction that fools the quadrature encoder.  It's very
> strange that the following errors are only in one direction.
>
> At $145US plus shipping, since Automation Technologies won't replace it,
> I'm going to cast a new mounting plate for one of the slightly smaller
> 1.27NM Bergerda AC servos.  They were destined for the ball screw upgrade
> (and I'd ordered the wrong size thinking they were the same torque as the
> DC ones).  So we'll see.  If the Bergerda does well on the heavier Y axis
> then problem solved.
>
> More as it unfolds.
>
> Oh I swapped motor/encoder sets between X and Y,and with the Y motor
> running the X axis the test program that runs the table back and forth no
> longer has a slightly different sound between changing direction CW
> compared to CCW.  So it appears that's also on the motor and not LinuxCNC
> nor the MESA.  And absolutely no errors in position on X.  Only now on the
> Y instead.  That lets the HP_UHU servo drive off the hook too.
>
> John
>
> > -Original Message-
> > From: Rick Moscoloni [mailto:rmoscol...@gmail.com]
> > Sent: September-19-21 10:12 AM
> > To: Enhanced Machine Controller (EMC)
> > Subject: Re: [Emc-users] DC Servo issues
> >
> > us digital encoders with a capacitor across dc+and- works without a
> > fault
> >
> > El dom, 19 sept 2021 a las 2:49, John Dammeyer ( >)
> > escribi�:
> >
> > > Over 10 years ago I bought two of these for the XY axis of the mill.
> > >
> > >
> https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor
> > >
> > > Also from US Digital the 250 line encoders.
> > > I had assembled HP_UHU kits and had on standby the Henrik Olsson
> > > replacement PIC processor modules although this photo shows the
> original
> > > processor.
> > > http://www.autoartisans.com/mill/HP_UHU_Modified.jpg
> > >
> > > One of the things that showed up right away was that with identical
> drives
> > > one motor ran hotter than the other.  Further investigation showed the
> > > resistance of the windings was different with the warmer motor having
> the
> > > lower resistance and inductance which matched the spec sheet.  By then
> it
> > > was too late to return the high resistance one so I decided to put what
> > > appeared to be the on spec motor on the Y axis since it had to carry
> more
> > > weight.  The X axis got the cooler and higher resistance motor.
> > >
> > > When I finally got it all together I had a lot of position errors and
> > > Henrik convinced me to trash the US Digital encoders which appeared to
> be
> > > losing counts and replace them with the CUI.  Changing to Henrik's
> module
> > > improved things and positioning was now reasonably accurate.  Until a
> short
> > > while ago on the X axis.
> > >
> > > I pulled the encoder off remounted things and the problem seemed to go
> > > away.  Well last week, after the center drilled holes were off from
> where
> > > the 1/4" drill bit went down I realized the problem had returned.
> After
> > > much mucking around it seems that the real issue is still with that X
> axis
> > > out of spec motor.
> > >
> > > What I did is swap motor+encoder from X <=> Y.  The cumulative position
> > > errors on X are now gone so that shows the HP_UHU drive was not the
> issue.
> > > What's really interesting is the heavier Y axis now regularly faults
> at 140
> > > ipm where before the other motor could do 150 ipm.
> > >
> > > Also interesting when I drop the speeds to below 130 it doesn't fault
> but
> > > I started seeing position errors.
> > >
> > > The G-Code test program
> > > G01 X0 Y0 F60
> > > X-4
> > > Y-1.1
> > > Y0
> > > X0
> > > Y-1.1
> > > Y0
> > > X5
> > > And so on for about 5 cycles.
> > >
> > > Now the X axis returns to 0 every single time from either side of 0.
> But
> > > the Y axis accumulates -0.020 or so error 

Re: [Emc-users] DC Servo issues

[John Figie]

John Figie


On Sun, Sep 19, 2021 at 2:07 PM John Dammeyer 
wrote:

>
>
> That's the question.  One possibility to try is to grab 110VAC line
> voltage. Put a bridge and caps on it and drive that motor with more than
> the 105VDC power supply.  I'll have to check if my transistors are rated
> for the 165VDC rectified voltage and I really would rather have them be
> 250V transitors.


I think you will need the 250V transistors and also need to consider a
shunt resistor and switch to keep the bus voltage from going too high when
you rapidly decelerate a motor.


> And then there's the filters on the board too. The UHU circuit was
> originally for up to about 75V.  The HP_UHU came about for higher voltage
> drives;  Just don't know if I built mine for more than 125VDC although the
> circuit design parts are for 11A.
>
> I _have_ tried one these motors with the STMBL but could never get it
> tuned and support from the designers was inadequate to help me so I gave
> up.
>
> I'd rather be machining...
>
> John
>
>
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] DC Servo issues

[Sam Sokolik]

Lol..  I certainly love the electrics part more than the machining most of
the time...

On Sun, Sep 19, 2021, 2:07 PM John Dammeyer  wrote:

> Hi Sam,
> See below.
> > From: Sam Sokolik [mailto:samco...@gmail.com]
> >
> > I have never used servo drives that close the loop..   I have always had
> > great luck with normal closed loop within linuxcnc.  (cheap used amc
> > drives)
> >
> > (Actually - I take that back - I have used the stmbl drives. so far only
> > for a spindle..)
> >
> > This is of course using mesa analog interface hardware.
> >
> > The only time I had issues with encoder counting was when I thought I
> could
> > get by with single ended encoders going over 8 ft...
> >
> > Look at something like this..  2 counts per rev,  2 axis with 4000?
> > counts per rev...  (and the encoders came installed on the servo, single
> > ended and I think they are us-digital)
> > If I was missing counts during these complicated sync moves - you would
> > certainly see it.
> >
> > https://www.youtube.com/watch?v=-4sKHBh6rDk
> >
> > (plus no 3rd party software to tune...)  - Granted you have the drives
> and
> > are familiar with them - at what point do you give up?
> >
> > sam
>
> That's the question.  One possibility to try is to grab 110VAC line
> voltage. Put a bridge and caps on it and drive that motor with more than
> the 105VDC power supply.  I'll have to check if my transistors are rated
> for the 165VDC rectified voltage and I really would rather have them be
> 250V transitors.   And then there's the filters on the board too. The UHU
> circuit was originally for up to about 75V.  The HP_UHU came about for
> higher voltage drives;  Just don't know if I built mine for more than
> 125VDC although the circuit design parts are for 11A.
>
> I _have_ tried one these motors with the STMBL but could never get it
> tuned and support from the designers was inadequate to help me so I gave
> up.
>
> I'd rather be machining...
>
> John
>
>
>
> >
> > On Sun, Sep 19, 2021 at 12:59 PM John Dammeyer 
> > wrote:
> >
> > > Hi Rick,
> > > It may also have something to do with the DC Servo drive electronics.
> > > Although it's differential encoder signalling the design may have
> internal
> > > issues that are somewhat corrected by the Henk Olsson module.  I had
> both a
> > > small electrolytic and ceramic capacitors right by the US Digital
> encoders,
> > > which BTW, have been discontinued for a few years.  Perhaps that's why?
> > > Issues?
> > >
> > > I swapped the X and Y motor/encoder pair and sure enough the problem
> moved
> > > to the Y axis along with now only 120 IPM instead of 150 IPM.  Above
> that I
> > > get following errors.  Given that this motor has a higher winding
> > > resistance I'm going to guess it's not a 90VDC motor but is more
> likely a
> > > 180VDC motor that was shipped as a 90VDC.   Maybe the loading
> introduces
> > > noise in one direction that fools the quadrature encoder.  It's very
> > > strange that the following errors are only in one direction.
> > >
> > > At $145US plus shipping, since Automation Technologies won't replace
> it,
> > > I'm going to cast a new mounting plate for one of the slightly smaller
> > > 1.27NM Bergerda AC servos.  They were destined for the ball screw
> upgrade
> > > (and I'd ordered the wrong size thinking they were the same torque as
> the
> > > DC ones).  So we'll see.  If the Bergerda does well on the heavier Y
> axis
> > > then problem solved.
> > >
> > > More as it unfolds.
> > >
> > > Oh I swapped motor/encoder sets between X and Y,and with the Y motor
> > > running the X axis the test program that runs the table back and forth
> no
> > > longer has a slightly different sound between changing direction CW
> > > compared to CCW.  So it appears that's also on the motor and not
> LinuxCNC
> > > nor the MESA.  And absolutely no errors in position on X.  Only now on
> the
> > > Y instead.  That lets the HP_UHU servo drive off the hook too.
> > >
> > > John
> > >
> > > > -Original Message-
> > > > From: Rick Moscoloni [mailto:rmoscol...@gmail.com]
> > > > Sent: September-19-21 10:12 AM
> > > > To: Enhanced Machine Controller (EMC)
> > > > Subject: Re: [Emc-users] DC Servo issues
> > > >
> > > > us digital encoders with a capacitor across dc+and- works without a
> > > > fault
> > > >
> > > > El dom, 19 sept 2021 a las 2:49, John Dammeyer (<
> jo...@autoartisans.com
> > > >)
> > > > escribi?:
> > > >
> > > > > Over 10 years ago I bought two of these for the XY axis of the
> mill.
> > > > >
> > > > >
> > >
> https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor
> > > > >
> > > > > Also from US Digital the 250 line encoders.
> > > > > I had assembled HP_UHU kits and had on standby the Henrik Olsson
> > > > > replacement PIC processor modules although this photo shows the
> > > original
> > > > > processor.
> > > > > http://www.autoartisans.com/mill/HP_UHU_Modified.jpg
> > > > >
> > > > > One 

Re: [Emc-users] DC Servo issues

[John Dammeyer]

Hi Sam,
See below.
> From: Sam Sokolik [mailto:samco...@gmail.com]
> 
> I have never used servo drives that close the loop..   I have always had
> great luck with normal closed loop within linuxcnc.  (cheap used amc
> drives)
> 
> (Actually - I take that back - I have used the stmbl drives. so far only
> for a spindle..)
> 
> This is of course using mesa analog interface hardware.
> 
> The only time I had issues with encoder counting was when I thought I could
> get by with single ended encoders going over 8 ft...
> 
> Look at something like this..  2 counts per rev,  2 axis with 4000?
> counts per rev...  (and the encoders came installed on the servo, single
> ended and I think they are us-digital)
> If I was missing counts during these complicated sync moves - you would
> certainly see it.
> 
> https://www.youtube.com/watch?v=-4sKHBh6rDk
> 
> (plus no 3rd party software to tune...)  - Granted you have the drives and
> are familiar with them - at what point do you give up?
> 
> sam

That's the question.  One possibility to try is to grab 110VAC line voltage. 
Put a bridge and caps on it and drive that motor with more than the 105VDC 
power supply.  I'll have to check if my transistors are rated for the 165VDC 
rectified voltage and I really would rather have them be 250V transitors.   And 
then there's the filters on the board too. The UHU circuit was originally for 
up to about 75V.  The HP_UHU came about for higher voltage drives;  Just don't 
know if I built mine for more than 125VDC although the circuit design parts are 
for 11A.

I _have_ tried one these motors with the STMBL but could never get it tuned and 
support from the designers was inadequate to help me so I gave up.

I'd rather be machining...

John



> 
> On Sun, Sep 19, 2021 at 12:59 PM John Dammeyer 
> wrote:
> 
> > Hi Rick,
> > It may also have something to do with the DC Servo drive electronics.
> > Although it's differential encoder signalling the design may have internal
> > issues that are somewhat corrected by the Henk Olsson module.  I had both a
> > small electrolytic and ceramic capacitors right by the US Digital encoders,
> > which BTW, have been discontinued for a few years.  Perhaps that's why?
> > Issues?
> >
> > I swapped the X and Y motor/encoder pair and sure enough the problem moved
> > to the Y axis along with now only 120 IPM instead of 150 IPM.  Above that I
> > get following errors.  Given that this motor has a higher winding
> > resistance I'm going to guess it's not a 90VDC motor but is more likely a
> > 180VDC motor that was shipped as a 90VDC.   Maybe the loading introduces
> > noise in one direction that fools the quadrature encoder.  It's very
> > strange that the following errors are only in one direction.
> >
> > At $145US plus shipping, since Automation Technologies won't replace it,
> > I'm going to cast a new mounting plate for one of the slightly smaller
> > 1.27NM Bergerda AC servos.  They were destined for the ball screw upgrade
> > (and I'd ordered the wrong size thinking they were the same torque as the
> > DC ones).  So we'll see.  If the Bergerda does well on the heavier Y axis
> > then problem solved.
> >
> > More as it unfolds.
> >
> > Oh I swapped motor/encoder sets between X and Y,and with the Y motor
> > running the X axis the test program that runs the table back and forth no
> > longer has a slightly different sound between changing direction CW
> > compared to CCW.  So it appears that's also on the motor and not LinuxCNC
> > nor the MESA.  And absolutely no errors in position on X.  Only now on the
> > Y instead.  That lets the HP_UHU servo drive off the hook too.
> >
> > John
> >
> > > -Original Message-
> > > From: Rick Moscoloni [mailto:rmoscol...@gmail.com]
> > > Sent: September-19-21 10:12 AM
> > > To: Enhanced Machine Controller (EMC)
> > > Subject: Re: [Emc-users] DC Servo issues
> > >
> > > us digital encoders with a capacitor across dc+and- works without a
> > > fault
> > >
> > > El dom, 19 sept 2021 a las 2:49, John Dammeyer ( > >)
> > > escribi?:
> > >
> > > > Over 10 years ago I bought two of these for the XY axis of the mill.
> > > >
> > > >
> > https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor
> > > >
> > > > Also from US Digital the 250 line encoders.
> > > > I had assembled HP_UHU kits and had on standby the Henrik Olsson
> > > > replacement PIC processor modules although this photo shows the
> > original
> > > > processor.
> > > > http://www.autoartisans.com/mill/HP_UHU_Modified.jpg
> > > >
> > > > One of the things that showed up right away was that with identical
> > drives
> > > > one motor ran hotter than the other.  Further investigation showed the
> > > > resistance of the windings was different with the warmer motor having
> > the
> > > > lower resistance and inductance which matched the spec sheet.  By then
> > it
> > > > was too late to return the high resistance one so I decided to put 

Re: [Emc-users] DC Servo issues

[Sam Sokolik]

I have never used servo drives that close the loop..   I have always had
great luck with normal closed loop within linuxcnc.  (cheap used amc
drives)

(Actually - I take that back - I have used the stmbl drives. so far only
for a spindle..)

This is of course using mesa analog interface hardware.

The only time I had issues with encoder counting was when I thought I could
get by with single ended encoders going over 8 ft...

Look at something like this..  2 counts per rev,  2 axis with 4000?
counts per rev...  (and the encoders came installed on the servo, single
ended and I think they are us-digital)
If I was missing counts during these complicated sync moves - you would
certainly see it.

https://www.youtube.com/watch?v=-4sKHBh6rDk

(plus no 3rd party software to tune...)  - Granted you have the drives and
are familiar with them - at what point do you give up?

sam

On Sun, Sep 19, 2021 at 12:59 PM John Dammeyer 
wrote:

> Hi Rick,
> It may also have something to do with the DC Servo drive electronics.
> Although it's differential encoder signalling the design may have internal
> issues that are somewhat corrected by the Henk Olsson module.  I had both a
> small electrolytic and ceramic capacitors right by the US Digital encoders,
> which BTW, have been discontinued for a few years.  Perhaps that's why?
> Issues?
>
> I swapped the X and Y motor/encoder pair and sure enough the problem moved
> to the Y axis along with now only 120 IPM instead of 150 IPM.  Above that I
> get following errors.  Given that this motor has a higher winding
> resistance I'm going to guess it's not a 90VDC motor but is more likely a
> 180VDC motor that was shipped as a 90VDC.   Maybe the loading introduces
> noise in one direction that fools the quadrature encoder.  It's very
> strange that the following errors are only in one direction.
>
> At $145US plus shipping, since Automation Technologies won't replace it,
> I'm going to cast a new mounting plate for one of the slightly smaller
> 1.27NM Bergerda AC servos.  They were destined for the ball screw upgrade
> (and I'd ordered the wrong size thinking they were the same torque as the
> DC ones).  So we'll see.  If the Bergerda does well on the heavier Y axis
> then problem solved.
>
> More as it unfolds.
>
> Oh I swapped motor/encoder sets between X and Y,and with the Y motor
> running the X axis the test program that runs the table back and forth no
> longer has a slightly different sound between changing direction CW
> compared to CCW.  So it appears that's also on the motor and not LinuxCNC
> nor the MESA.  And absolutely no errors in position on X.  Only now on the
> Y instead.  That lets the HP_UHU servo drive off the hook too.
>
> John
>
> > -Original Message-
> > From: Rick Moscoloni [mailto:rmoscol...@gmail.com]
> > Sent: September-19-21 10:12 AM
> > To: Enhanced Machine Controller (EMC)
> > Subject: Re: [Emc-users] DC Servo issues
> >
> > us digital encoders with a capacitor across dc+and- works without a
> > fault
> >
> > El dom, 19 sept 2021 a las 2:49, John Dammeyer ( >)
> > escribi�:
> >
> > > Over 10 years ago I bought two of these for the XY axis of the mill.
> > >
> > >
> https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor
> > >
> > > Also from US Digital the 250 line encoders.
> > > I had assembled HP_UHU kits and had on standby the Henrik Olsson
> > > replacement PIC processor modules although this photo shows the
> original
> > > processor.
> > > http://www.autoartisans.com/mill/HP_UHU_Modified.jpg
> > >
> > > One of the things that showed up right away was that with identical
> drives
> > > one motor ran hotter than the other.  Further investigation showed the
> > > resistance of the windings was different with the warmer motor having
> the
> > > lower resistance and inductance which matched the spec sheet.  By then
> it
> > > was too late to return the high resistance one so I decided to put what
> > > appeared to be the on spec motor on the Y axis since it had to carry
> more
> > > weight.  The X axis got the cooler and higher resistance motor.
> > >
> > > When I finally got it all together I had a lot of position errors and
> > > Henrik convinced me to trash the US Digital encoders which appeared to
> be
> > > losing counts and replace them with the CUI.  Changing to Henrik's
> module
> > > improved things and positioning was now reasonably accurate.  Until a
> short
> > > while ago on the X axis.
> > >
> > > I pulled the encoder off remounted things and the problem seemed to go
> > > away.  Well last week, after the center drilled holes were off from
> where
> > > the 1/4" drill bit went down I realized the problem had returned.
> After
> > > much mucking around it seems that the real issue is still with that X
> axis
> > > out of spec motor.
> > >
> > > What I did is swap motor+encoder from X <=> Y.  The cumulative position
> > > errors on X are now gone so that shows the HP_UHU 

Re: [Emc-users] Heidenhain IBV 610 troubles

[John Figie]

John Figie


I forgot to post more details about the Hedenhain TNC 151 interpolator.
> http://machineability.com/Bridgeport_series_II.html
>
> On the other hand my Bridgeport series II Interact conversion which had a
> Heidenhain TNC seemed to have some comparators and logic to do
> interpolation and output a higher frequency AqB signal. The interpolation
> was not very fine, in fact it is 20 steps per 360 degrees of sin. - 5 steps
> per 90 degrees, fairly easy to do with comparators.
>
> Regards,
>
> John Figie
>
>
>>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Heidenhain IBV 610 troubles

[John Figie]

I agree with Eric, Many Sin - Cos encoders like SICK and Heidenhain output
a DC reference voltage on the A- and B- signals and only the A+ and B+
actually change around the reference. Some encoders like Kubler I think
have true complementary differential outputs. In either case the
differential amplifier that receives the signals should be able to handle
either case.  I know this from first hand engineering experience with
interfacing Sin Cos encoders to the industrial servo drives I helped
develop for my former employer.

I do not know anything about what is inside the Heidenhain interpolation
box. What we did was use ADCs and FPGA logic to do the sin - cos
interpolation. The method we used was to first convert the sin and cos to
the tangent which is the ratio of sin/cos then use arc tangent lookup. By
using the tangent any amplitude changes from cable lengths or other common
factors will cancel. It is assumed that the sin and cos inputs are both
affected equally. Of course there is more to it because the tan function
does not behave well for all angles, it goes to infinity as angle
approaches 90 and 270 so you need to know what octant the encoder is in and
also use the cotangent.

On the other hand my Bridgeport series II Interact conversion which had a
Heidenhain TNC seemed to have some comparators and logic to do
interpolation and output a higher frequency AqB signal. The interpolation
was not very fine, in fact it is 20 steps per 360 degrees of sin. - 5 steps
per 90 degrees, fairly easy to do with comparators.

Regards,

John Figie


On Sun, Sep 19, 2021 at 11:25 AM Eric Keller  wrote:

> I don't think that's true that they have to be compliments.  There probably
> is a way to adjust the levels like I mentioned in my previous email. Is the
> manual online, or did you just get a paper copy? I wonder if it's an issue
> with the signals not being +/- with respect to ground. Is it a Heidenhein
> encoder?
> Eric Keller
> Boalsburg, Pennsylvania
>
> On Sun, Sep 19, 2021 at 11:50 AM Curtis Dutton  wrote:
>
> > Ok after thinking about it more, the interpolate is expecting that the
> > incoming sin/cos signals a,a* are actual inverse values. however this
> > encoder is single ended, it just has a and b signals. the a* and b*
> signals
> > are a sort of reference voltage and never change. I'll experiment with it
> > some more tomorrow
> >
> >
> > On Sun, Sep 19, 2021, 12:55 AM Curtis Dutton  wrote:
> >
> > > It is an incremental. Magnetic sensor. Gear tooth with I think 256
> teeth.
> > > One sin/cos cycle per tooth.
> > >
> > > On Sat, Sep 18, 2021, 10:56 PM Ralph Stirling <
> > > ralph.stirl...@wallawalla.edu> wrote:
> > >
> > >> A lot of very high resolution, and older encoders have
> > >> sine wave gratings, which give sine and cosine waveforms
> > >> on the A and B channels.  These are connected to an
> > >> interpolator box that contains A/D converters and logic
> > >> to generate quadrature pulses.  The higher the interpolation
> > >> ratio, the lower the max velocity allowed.
> > >>
> > >> -- Ralph
> > >> 
> > >> From: Gene Heskett [ghesk...@shentel.net]
> > >> Sent: Saturday, September 18, 2021 5:22 PM
> > >> To: emc-users@lists.sourceforge.net
> > >> Subject: Re: [Emc-users] Heidenhain IBV 610 troubles
> > >>
> > >> I don't think you have an encoder, but a resolver. If you are getting
> > one
> > >> sinesoid per full turn, its a resolver.
> > >>
> > >> > Anyhow it doesn't work and I'm not sure how to troubleshoot the
> black
> > >> > box. I have the manuals and I have tried various combinations of the
> > >> > dip swithches inside.
> > >> >
> > >> > does anyone have any troubleshooting tips or stories about their use
> > >> > of an interpolater box?
> > >> >
> > >> >
> > >> > Thanks,
> > >> >Curt
> > >> >
> > >> > ___
> > >> > Emc-users mailing list
> > >> > Emc-users@lists.sourceforge.net
> > >> >
> > >>
> >
> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C5a5b014bf3fc4481176208d97b03a93b%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C1%7C637676077932698528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=sowEIC7aWNESysLAlCjxOMk84Inwx9pFjz4IRVk6vIo%3Dreserved=0
> > >>
> > >>
> > >> Cheers, Gene Heskett
> > >> --
> > >> "There are four boxes to be used in defense of liberty:
> > >>  soap, ballot, jury, and ammo. Please use in that order."
> > >> -Ed Howdershelt (Author)
> > >> If we desire respect for the law, we must first make the law
> > respectable.
> > >>  - Louis D. Brandeis
> > >> Genes Web page <
> > >>
> >
> 

Re: [Emc-users] Heidenhain IBV 610 troubles

[Curtis Dutton]

I have found a manual online. It is a fanuc encoder on the top of a spindle
motor.

I don't seee any trim pots inside the box. Just 5 jumpers.


1is it for 90 or 270 deg for reference.
2nd is high or low impedence input. (not sure what this does)

3-5 is interpolation amount (5x vs 10x) and output frequency settings.



On Sun, Sep 19, 2021, 12:25 PM Eric Keller  wrote:

> I don't think that's true that they have to be compliments.  There probably
> is a way to adjust the levels like I mentioned in my previous email. Is the
> manual online, or did you just get a paper copy? I wonder if it's an issue
> with the signals not being +/- with respect to ground. Is it a Heidenhein
> encoder?
> Eric Keller
> Boalsburg, Pennsylvania
>
> On Sun, Sep 19, 2021 at 11:50 AM Curtis Dutton  wrote:
>
> > Ok after thinking about it more, the interpolate is expecting that the
> > incoming sin/cos signals a,a* are actual inverse values. however this
> > encoder is single ended, it just has a and b signals. the a* and b*
> signals
> > are a sort of reference voltage and never change. I'll experiment with it
> > some more tomorrow
> >
> >
> > On Sun, Sep 19, 2021, 12:55 AM Curtis Dutton  wrote:
> >
> > > It is an incremental. Magnetic sensor. Gear tooth with I think 256
> teeth.
> > > One sin/cos cycle per tooth.
> > >
> > > On Sat, Sep 18, 2021, 10:56 PM Ralph Stirling <
> > > ralph.stirl...@wallawalla.edu> wrote:
> > >
> > >> A lot of very high resolution, and older encoders have
> > >> sine wave gratings, which give sine and cosine waveforms
> > >> on the A and B channels.  These are connected to an
> > >> interpolator box that contains A/D converters and logic
> > >> to generate quadrature pulses.  The higher the interpolation
> > >> ratio, the lower the max velocity allowed.
> > >>
> > >> -- Ralph
> > >> 
> > >> From: Gene Heskett [ghesk...@shentel.net]
> > >> Sent: Saturday, September 18, 2021 5:22 PM
> > >> To: emc-users@lists.sourceforge.net
> > >> Subject: Re: [Emc-users] Heidenhain IBV 610 troubles
> > >>
> > >> I don't think you have an encoder, but a resolver. If you are getting
> > one
> > >> sinesoid per full turn, its a resolver.
> > >>
> > >> > Anyhow it doesn't work and I'm not sure how to troubleshoot the
> black
> > >> > box. I have the manuals and I have tried various combinations of the
> > >> > dip swithches inside.
> > >> >
> > >> > does anyone have any troubleshooting tips or stories about their use
> > >> > of an interpolater box?
> > >> >
> > >> >
> > >> > Thanks,
> > >> >Curt
> > >> >
> > >> > ___
> > >> > Emc-users mailing list
> > >> > Emc-users@lists.sourceforge.net
> > >> >
> > >>
> >
> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C5a5b014bf3fc4481176208d97b03a93b%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C1%7C637676077932698528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=sowEIC7aWNESysLAlCjxOMk84Inwx9pFjz4IRVk6vIo%3Dreserved=0
> > >>
> > >>
> > >> Cheers, Gene Heskett
> > >> --
> > >> "There are four boxes to be used in defense of liberty:
> > >>  soap, ballot, jury, and ammo. Please use in that order."
> > >> -Ed Howdershelt (Author)
> > >> If we desire respect for the law, we must first make the law
> > respectable.
> > >>  - Louis D. Brandeis
> > >> Genes Web page <
> > >>
> >
> https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgeneslinuxbox.net%3A6309%2Fgenedata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C5a5b014bf3fc4481176208d97b03a93b%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C1%7C637676077932698528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=HxeTFPS47gukrRBopVJJ939Wg4sEwHPPRremv092Uy0%3Dreserved=0
> > >> >
> > >>
> > >>
> > >> ___
> > >> Emc-users mailing list
> > >> Emc-users@lists.sourceforge.net
> > >> https://lists.sourceforge.net/lists/listinfo/emc-users
> > >>
> > >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] DC Servo issues

[John Dammeyer]

Hi Rick,
It may also have something to do with the DC Servo drive electronics.  Although 
it's differential encoder signalling the design may have internal issues that 
are somewhat corrected by the Henk Olsson module.  I had both a small 
electrolytic and ceramic capacitors right by the US Digital encoders, which 
BTW, have been discontinued for a few years.  Perhaps that's why?  Issues?

I swapped the X and Y motor/encoder pair and sure enough the problem moved to 
the Y axis along with now only 120 IPM instead of 150 IPM.  Above that I get 
following errors.  Given that this motor has a higher winding resistance I'm 
going to guess it's not a 90VDC motor but is more likely a 180VDC motor that 
was shipped as a 90VDC.   Maybe the loading introduces noise in one direction 
that fools the quadrature encoder.  It's very strange that the following errors 
are only in one direction.  

At $145US plus shipping, since Automation Technologies won't replace it, I'm 
going to cast a new mounting plate for one of the slightly smaller 1.27NM 
Bergerda AC servos.  They were destined for the ball screw upgrade (and I'd 
ordered the wrong size thinking they were the same torque as the DC ones).  So 
we'll see.  If the Bergerda does well on the heavier Y axis then problem 
solved.   

More as it unfolds.  

Oh I swapped motor/encoder sets between X and Y,and with the Y motor running 
the X axis the test program that runs the table back and forth no longer has a 
slightly different sound between changing direction CW compared to CCW.  So it 
appears that's also on the motor and not LinuxCNC nor the MESA.  And absolutely 
no errors in position on X.  Only now on the Y instead.  That lets the HP_UHU 
servo drive off the hook too.

John

> -Original Message-
> From: Rick Moscoloni [mailto:rmoscol...@gmail.com]
> Sent: September-19-21 10:12 AM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] DC Servo issues
> 
> us digital encoders with a capacitor across dc+and- works without a
> fault
> 
> El dom, 19 sept 2021 a las 2:49, John Dammeyer ()
> escribi�:
> 
> > Over 10 years ago I bought two of these for the XY axis of the mill.
> >
> > https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor
> >
> > Also from US Digital the 250 line encoders.
> > I had assembled HP_UHU kits and had on standby the Henrik Olsson
> > replacement PIC processor modules although this photo shows the original
> > processor.
> > http://www.autoartisans.com/mill/HP_UHU_Modified.jpg
> >
> > One of the things that showed up right away was that with identical drives
> > one motor ran hotter than the other.  Further investigation showed the
> > resistance of the windings was different with the warmer motor having the
> > lower resistance and inductance which matched the spec sheet.  By then it
> > was too late to return the high resistance one so I decided to put what
> > appeared to be the on spec motor on the Y axis since it had to carry more
> > weight.  The X axis got the cooler and higher resistance motor.
> >
> > When I finally got it all together I had a lot of position errors and
> > Henrik convinced me to trash the US Digital encoders which appeared to be
> > losing counts and replace them with the CUI.  Changing to Henrik's module
> > improved things and positioning was now reasonably accurate.  Until a short
> > while ago on the X axis.
> >
> > I pulled the encoder off remounted things and the problem seemed to go
> > away.  Well last week, after the center drilled holes were off from where
> > the 1/4" drill bit went down I realized the problem had returned.  After
> > much mucking around it seems that the real issue is still with that X axis
> > out of spec motor.
> >
> > What I did is swap motor+encoder from X <=> Y.  The cumulative position
> > errors on X are now gone so that shows the HP_UHU drive was not the issue.
> > What's really interesting is the heavier Y axis now regularly faults at 140
> > ipm where before the other motor could do 150 ipm.
> >
> > Also interesting when I drop the speeds to below 130 it doesn't fault but
> > I started seeing position errors.
> >
> > The G-Code test program
> > G01 X0 Y0 F60
> > X-4
> > Y-1.1
> > Y0
> > X0
> > Y-1.1
> > Y0
> > X5
> > And so on for about 5 cycles.
> >
> > Now the X axis returns to 0 every single time from either side of 0.  But
> > the Y axis accumulates -0.020 or so error every time the program runs just
> > like X used to with that motor.  Always only negative values.  So strange.
> >
> > Also when that motor was on the X axis the sound of the system when
> > changing direction was clunky sounding in one direction and not the other
> > under G-Code.  The change direction with jogging keys wasn't like that.
> >
> > I don't think it's worthwhile to spend the time to figure out what's
> > wrong.  Seems pointless to continue to use a motor that isn't up to spec.
> > Probably better to just install one 

Re: [Emc-users] DC Servo issues

[Rick Moscoloni]

us digital encoders with a capacitor across dc+and- works without a
fault

El dom, 19 sept 2021 a las 2:49, John Dammeyer ()
escribió:

> Over 10 years ago I bought two of these for the XY axis of the mill.
>
> https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor
>
> Also from US Digital the 250 line encoders.
> I had assembled HP_UHU kits and had on standby the Henrik Olsson
> replacement PIC processor modules although this photo shows the original
> processor.
> http://www.autoartisans.com/mill/HP_UHU_Modified.jpg
>
> One of the things that showed up right away was that with identical drives
> one motor ran hotter than the other.  Further investigation showed the
> resistance of the windings was different with the warmer motor having the
> lower resistance and inductance which matched the spec sheet.  By then it
> was too late to return the high resistance one so I decided to put what
> appeared to be the on spec motor on the Y axis since it had to carry more
> weight.  The X axis got the cooler and higher resistance motor.
>
> When I finally got it all together I had a lot of position errors and
> Henrik convinced me to trash the US Digital encoders which appeared to be
> losing counts and replace them with the CUI.  Changing to Henrik's module
> improved things and positioning was now reasonably accurate.  Until a short
> while ago on the X axis.
>
> I pulled the encoder off remounted things and the problem seemed to go
> away.  Well last week, after the center drilled holes were off from where
> the 1/4" drill bit went down I realized the problem had returned.  After
> much mucking around it seems that the real issue is still with that X axis
> out of spec motor.
>
> What I did is swap motor+encoder from X <=> Y.  The cumulative position
> errors on X are now gone so that shows the HP_UHU drive was not the issue.
> What's really interesting is the heavier Y axis now regularly faults at 140
> ipm where before the other motor could do 150 ipm.
>
> Also interesting when I drop the speeds to below 130 it doesn't fault but
> I started seeing position errors.
>
> The G-Code test program
> G01 X0 Y0 F60
> X-4
> Y-1.1
> Y0
> X0
> Y-1.1
> Y0
> X5
> And so on for about 5 cycles.
>
> Now the X axis returns to 0 every single time from either side of 0.  But
> the Y axis accumulates -0.020 or so error every time the program runs just
> like X used to with that motor.  Always only negative values.  So strange.
>
> Also when that motor was on the X axis the sound of the system when
> changing direction was clunky sounding in one direction and not the other
> under G-Code.  The change direction with jogging keys wasn't like that.
>
> I don't think it's worthwhile to spend the time to figure out what's
> wrong.  Seems pointless to continue to use a motor that isn't up to spec.
> Probably better to just install one of the Bergerda AC Servos I have here
> that I was saving for the Ball Screw upgrade.  Especially since
> AutomationTechnologies wouldn't replace the motor even though it was
> clearly out of spec.  Not about to buy anything else from them.
>
> John Dammeyer
>
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Heidenhain IBV 610 troubles

[Eric Keller]

I don't think that's true that they have to be compliments.  There probably
is a way to adjust the levels like I mentioned in my previous email. Is the
manual online, or did you just get a paper copy? I wonder if it's an issue
with the signals not being +/- with respect to ground. Is it a Heidenhein
encoder?
Eric Keller
Boalsburg, Pennsylvania

On Sun, Sep 19, 2021 at 11:50 AM Curtis Dutton  wrote:

> Ok after thinking about it more, the interpolate is expecting that the
> incoming sin/cos signals a,a* are actual inverse values. however this
> encoder is single ended, it just has a and b signals. the a* and b* signals
> are a sort of reference voltage and never change. I'll experiment with it
> some more tomorrow
>
>
> On Sun, Sep 19, 2021, 12:55 AM Curtis Dutton  wrote:
>
> > It is an incremental. Magnetic sensor. Gear tooth with I think 256 teeth.
> > One sin/cos cycle per tooth.
> >
> > On Sat, Sep 18, 2021, 10:56 PM Ralph Stirling <
> > ralph.stirl...@wallawalla.edu> wrote:
> >
> >> A lot of very high resolution, and older encoders have
> >> sine wave gratings, which give sine and cosine waveforms
> >> on the A and B channels.  These are connected to an
> >> interpolator box that contains A/D converters and logic
> >> to generate quadrature pulses.  The higher the interpolation
> >> ratio, the lower the max velocity allowed.
> >>
> >> -- Ralph
> >> 
> >> From: Gene Heskett [ghesk...@shentel.net]
> >> Sent: Saturday, September 18, 2021 5:22 PM
> >> To: emc-users@lists.sourceforge.net
> >> Subject: Re: [Emc-users] Heidenhain IBV 610 troubles
> >>
> >> I don't think you have an encoder, but a resolver. If you are getting
> one
> >> sinesoid per full turn, its a resolver.
> >>
> >> > Anyhow it doesn't work and I'm not sure how to troubleshoot the black
> >> > box. I have the manuals and I have tried various combinations of the
> >> > dip swithches inside.
> >> >
> >> > does anyone have any troubleshooting tips or stories about their use
> >> > of an interpolater box?
> >> >
> >> >
> >> > Thanks,
> >> >Curt
> >> >
> >> > ___
> >> > Emc-users mailing list
> >> > Emc-users@lists.sourceforge.net
> >> >
> >>
> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C5a5b014bf3fc4481176208d97b03a93b%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C1%7C637676077932698528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=sowEIC7aWNESysLAlCjxOMk84Inwx9pFjz4IRVk6vIo%3Dreserved=0
> >>
> >>
> >> Cheers, Gene Heskett
> >> --
> >> "There are four boxes to be used in defense of liberty:
> >>  soap, ballot, jury, and ammo. Please use in that order."
> >> -Ed Howdershelt (Author)
> >> If we desire respect for the law, we must first make the law
> respectable.
> >>  - Louis D. Brandeis
> >> Genes Web page <
> >>
> https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgeneslinuxbox.net%3A6309%2Fgenedata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C5a5b014bf3fc4481176208d97b03a93b%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C1%7C637676077932698528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=HxeTFPS47gukrRBopVJJ939Wg4sEwHPPRremv092Uy0%3Dreserved=0
> >> >
> >>
> >>
> >> ___
> >> Emc-users mailing list
> >> Emc-users@lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>
> >
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Heidenhain IBV 610 troubles

[Curtis Dutton]

Ok after thinking about it more, the interpolate is expecting that the
incoming sin/cos signals a,a* are actual inverse values. however this
encoder is single ended, it just has a and b signals. the a* and b* signals
are a sort of reference voltage and never change. I'll experiment with it
some more tomorrow


On Sun, Sep 19, 2021, 12:55 AM Curtis Dutton  wrote:

> It is an incremental. Magnetic sensor. Gear tooth with I think 256 teeth.
> One sin/cos cycle per tooth.
>
> On Sat, Sep 18, 2021, 10:56 PM Ralph Stirling <
> ralph.stirl...@wallawalla.edu> wrote:
>
>> A lot of very high resolution, and older encoders have
>> sine wave gratings, which give sine and cosine waveforms
>> on the A and B channels.  These are connected to an
>> interpolator box that contains A/D converters and logic
>> to generate quadrature pulses.  The higher the interpolation
>> ratio, the lower the max velocity allowed.
>>
>> -- Ralph
>> 
>> From: Gene Heskett [ghesk...@shentel.net]
>> Sent: Saturday, September 18, 2021 5:22 PM
>> To: emc-users@lists.sourceforge.net
>> Subject: Re: [Emc-users] Heidenhain IBV 610 troubles
>>
>> I don't think you have an encoder, but a resolver. If you are getting one
>> sinesoid per full turn, its a resolver.
>>
>> > Anyhow it doesn't work and I'm not sure how to troubleshoot the black
>> > box. I have the manuals and I have tried various combinations of the
>> > dip swithches inside.
>> >
>> > does anyone have any troubleshooting tips or stories about their use
>> > of an interpolater box?
>> >
>> >
>> > Thanks,
>> >Curt
>> >
>> > ___
>> > Emc-users mailing list
>> > Emc-users@lists.sourceforge.net
>> >
>> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C5a5b014bf3fc4481176208d97b03a93b%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C1%7C637676077932698528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=sowEIC7aWNESysLAlCjxOMk84Inwx9pFjz4IRVk6vIo%3Dreserved=0
>>
>>
>> Cheers, Gene Heskett
>> --
>> "There are four boxes to be used in defense of liberty:
>>  soap, ballot, jury, and ammo. Please use in that order."
>> -Ed Howdershelt (Author)
>> If we desire respect for the law, we must first make the law respectable.
>>  - Louis D. Brandeis
>> Genes Web page <
>> https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgeneslinuxbox.net%3A6309%2Fgenedata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C5a5b014bf3fc4481176208d97b03a93b%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C1%7C637676077932698528%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=HxeTFPS47gukrRBopVJJ939Wg4sEwHPPRremv092Uy0%3Dreserved=0
>> >
>>
>>
>> ___
>> Emc-users mailing list
>> Emc-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/emc-users
>>
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] DC Servo issues

[Bari]

On 9/19/21 00:44, John Dammeyer wrote:


Over 10 years ago I bought two of these for the XY axis of the mill.
https://www.automationtechnologiesinc.com/products-page/dc-servo-motor/nema34-1125ozin-dual-shaft-servo-motor



One of the things that showed up right away was that with identical drives one 
motor ran hotter than the other.  Further investigation showed the resistance 
of the windings was different with the warmer motor having the lower resistance 
and inductance which matched the spec sheet.  By then it was too late to return 
the high resistance one so I decided to put what appeared to be the on spec 
motor on the Y axis since it had to carry more weight.  The X axis got the 
cooler and higher resistance motor.
Especially since AutomationTechnologies wouldn't replace the motor even though 
it was clearly out of spec.  Not about to buy anything else from them.



They are local for me. The owner is a nice enough guy but he also 
problems with getting reliable consistent parts from his homeland.


I only buy things from them that I expect to be like a kit that needs to 
be cleaned and assembled properly before use. I have had to return 
radial bearings with detents and linear bearings with crud inside or 
flat spots. We call them crunchy bearings. CNC mills come with red oxide 
treated fasteners and without nuts on the end of ballscrews so you can't 
adjust preloads unless you shim or replace with proper screws. Cables 
are assembled without the use of strain reliefs.


Red oxide treated fasteners  https://postimg.cc/jnhmsRhq

No strain relief  https://postimg.cc/7bqwTvvy

1mm of lash  https://postimg.cc/w1bvqpWk




___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users