Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

I don't recall if I finished off this thread with a report on the results.
Here's a photo of how it worked out.  I connected the encoder to a
dsPIC33ch128mp504 which was on a PIM installed into the Microchip Explorer
16 development board.  I used my ELS to run the motor and encoder pulses
were nicely formed and the dsPIC software reported both position and RPM.  I
have a photo of that setup but it's too large for the forum.

Looking at other stepper motors (size 23) I see that many don't even have
the holes this motor has for mounting a plate so Roland's idea might be
better.

John


> -Original Message-
> From: Roland Jollivet [mailto:roland.jolli...@gmail.com]
> Sent: June 26, 2023 10:17 AM
> To: Enhanced Machine Controller (EMC)
> Subject: [Emc-users] Drilling holes in the back of a stepper motor
> 
> You have such a large flat surface area there. Design an encoder mount
> plate of similar size where the end result is also has a flat surface.
> 
> Rough and clean the back of the motor up, then use a decent polyurethane
> adhesive to bond it on. During the setup you could use a jig to keep it
> concentric with the shaft.
> Design it in such a way that you can still replace the encoder if need be.
> 
> Roland
> 
> 
> 
> 
> On Sun, 25 Jun 2023 at 05:31, John Dammeyer 
> wrote:
> 
> > I want to add an encoder onto the back of this stepper motor.  I can
> > install
> > either a US Digital or a CUI since both mounting flanges can extend out
> > near
> > the edges of the back mounting plate.
> >
> >
> >
> > Is there any reason I can't clamp the motor in a vice and pop in two
holes
> > and tap them with a bottom tap at the spacing of the mounting flange?
> >
> > John
> >
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> 
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 7/30/23 02:29, John Dammeyer wrote:

Gene,
I think you are misreading the data sheet.  The 115K baud is for setting up
the unit.  Ie. Pulses per rev.  Once that's done the serial isn't used
anymore.
That didn't stick out very well in my skim read, thanks.  That leaves 
the 8 bit resolution which I a guessing from the squiggles of the wheel, 
are repeated at 5 per revolution with the index being geared to the 
synch point between the two patterns. We commonly use a 1 kliohertz 
servo loop, and if that A/D internal conversion is done at that rate or 
higher, the result will be essentially the same as direct optical.


I only use PID's in one machine here, the G0704, and have found that 
generally, the are a solution looking for a problem to solve that in the 
stepper world does not exist, particularly if the steppers are actually 
stepper/servo's.  They put the PID to good use because their control is 
directly tied to the src of the problem..There the error signal can and 
is used to control the magnitude of the motor current on a cycle by 
cycle basis. If the motor hasn't gotten into position, the error rises 
but is subject to a time limit as to how hard it can hit the motor, 
resulting in an alarm output that I tie into the e-stop, this only 
happens if the motor hits the immovable object. It can run into a 
stationary chuck jaw on my sheldon, see the error at 5 ipm movement, see 
the lockup and shut down linuxcnc which shuts down the psu's as all that 
in tied to F2 state, the carbide chip in the tool is not damaged and no 
mark is made on the chuck jaw, The driver itself drops power to the 
motor even faster, so the spring in the z drive bounces back about 5 
thou.  It takes that powerdown to reset the driver anyway, so it all 
Just Works.


And that has never occurred in actual operation, just in my testing by 
purposely running it into the stopped chuck.


The Sheldon and the 6040 mill both feed the stepgen back to motion, and 
a missed step would be a disaster, The 6040's Z & B are 3 phase 
stepper/servo's, XY are plain old oem steppers driven by 2m542's.  That 
B drive has worked so well on the 6040 that I've I've ordered stuff to 
make one like it for the G0704.  The BS-1 clone's motor was burned up by 
the new atpid and was both too big and too heavy for the G0704 and while 
accurate, was also slow at about .5 rpms. The B axis I made for the 6040 
can do well within a degree, and do it at 400 revs, is a 3nm 3phase 
driving a 5/1 worm which drives the chuck. That honking heavy spindle is 
lifted effortlessly by a 1nm 3phase.  The OEM Z failed to lift at 10% of 
the xy speeds of around 200 ipm.


I use what works.


I had two US Digital opticals on my DC servo's and they were crap.  I
switched to CUI units and all my problems went away


They should have just worked. But the $$ and mounting scared me off. The 
ultra cheap ($22) for the last one I bought, which has never been 
installed, the coupling failed and I replaced it with 2 layers of shrink 
tubing, which has worked, and continues to work, year after year for me. 
The one I bought to get the coupling is still in the box.



One has to assume the data sheet is correct when they say 8000 RPM with 2048
PPR.  The 115k Baud has nothing to do with that.


Depending on where you put it, 8000 might be too slow. That $22 Omron 
1000 ppr is rated to 6k. But  it came out of the box balanced and does 
not have enough swing to drive a 5i25 encoders single ended input, so 
there's a pair of rs485 translators in the cable making its low voltage 
balanced output into a 5 volt rail to rail signal. Works at 21k revs. 
The gear ratio in high gear in the G0704 is about an odd tooth over 7/1 
in high gear or 14/1 in low gear.  And I can bang that 90 volt 1hp motor 
with 125 volts and 18 amps. I'm amazed I haven't chewed up the nylon 
gears rigid tapping with it.



In either case, I'll likely set this encoder up for 200 PPR so that even
with micro-stepping I really still don't care for higher resolution since I
have a 25:1 planetary drive after the motor.  Assume I run the motor at 600
RPM max speed.  That's 10 RPS or 2000 pulses per rev or 20,000 with 10:1
micro-stepping. But wait... 600 RPM divided by 25 is 24 RPM or 0.4 RPS so
2.5 seconds to turn one revolution.


At 200, you may discover quatization noise that limits a PGain. My first 
optical for the G0704 spindle was a 66 slot brass disk, aka 264 edges 
per rev. quantization error drove the spindle wall to wall and made it 
noisy, like it was eating up the bearings in the head gears. The disk I 
made came loose and ate the opto's, which is when I rigged the Omron. 
Now its so quiet, with 5x higher PGain, that I have to look at it to 
verify its turning if set below 500 revs.  It was all electronic noise 
from too low an encoder count.


I even cheat on the gear change by running the motor at about 20 rpms if 
its not fully in gear, so I can be running at full song, reach up and 
change gears because 

Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Gene,
I think you are misreading the data sheet.  The 115K baud is for setting up
the unit.  Ie. Pulses per rev.  Once that's done the serial isn't used
anymore.
I had two US Digital opticals on my DC servo's and they were crap.  I
switched to CUI units and all my problems went away.  

One has to assume the data sheet is correct when they say 8000 RPM with 2048
PPR.  The 115k Baud has nothing to do with that.

In either case, I'll likely set this encoder up for 200 PPR so that even
with micro-stepping I really still don't care for higher resolution since I
have a 25:1 planetary drive after the motor.  Assume I run the motor at 600
RPM max speed.  That's 10 RPS or 2000 pulses per rev or 20,000 with 10:1
micro-stepping. But wait... 600 RPM divided by 25 is 24 RPM or 0.4 RPS so
2.5 seconds to turn one revolution. 

I'm thinking that if it takes 1 turn to release a TTS holder that's still
2.5 seconds.  Faster than me with a couple of wrenches.  And 25 seconds for
10 turns to release an R8 holder.  Also faster than me mucking with the nut.
Unless I would use an electric drill to spin it loose.  But then think of
the process.
1. Pick up two wrenches and loosen draw bar.
2. Put down wrenches.
3. Pick up portable drill and spin draw bar.  Now maybe impact drill could
do both.
4. Once 10 turns are complete catch R8 tool.

Twenty five seconds for it to be done automatically is actually not so bad.
John


> -Original Message-
> From: gene heskett [mailto:ghesk...@shentel.net]
> Sent: July 29, 2023 10:37 PM
> To: emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> 
> On 7/30/23 00:12, John Dammeyer wrote:
> > Hi Gene,
> > Best answered with the data sheet.
> > https://www.cuidevices.com/product/resource/amt11.pdf
> >
> A Capacitative device. Not a hall effect. The capacitative may be faster
> than a hall.  The reason I'm anti hall is the time lag in the hall world
> due to the time it takes to do the A/D conversions, which in turn means
> the hall encoded setup moves in jerks depending on the speed of that
> conversion. The 42C series of small motors, seen as ideal for a 3d
> printer, are a disaster because they don't move step by step but jerk by
> jerk, frequency of jerk determined to the speed of the A/D. Optical can
> determine where the motor is and which direction its turning from any
> edge of either A or B signals. At sufficient microstep divisors they can
> move quite pretty smoothly. I'd assume this time lag in less for the
> capacitative, but at the same time there is the Nyquist effect but the
> capacitative conversion is simpler, but the serial output still enforces
> a lag in the data stream. Only optical, which at higher and fixed
> resolutions is instant. The question remains then "is capacitative fast
> enough".  And that IDK. The 115 kilobaud output says no to me.  That
> alone would make me go shopping for a ABI encoder.
> 
> But I'm known to be picky. That's an optical $22 Omron 1000 ppr on the
> back shaft of the 1 hp in my g0704. With the gear ratio being
> switchable, and that encoder rated for 6k revs, but I watch spindle revs
> in the tach display. Top spindle is 3k revs. So times a hair over 7100,
> its seeing motor revs of nearly 21k revs at full song and not missing a
> beat for about 5 years now. Scale for high gear is a hair over 7100 per
> spindle rev.  I don't use the index, that is generated by a screw glued
> to the spindle going by an ATS-667 hall effect. That has its own
> direction problem I'm not smart enough to fix.   Someday...
> 
> > Not cheap in Canadian $.
> > https://www.digikey.ca/en/products/detail/cui-devices/AMT113Q-
> V/4835229
> >
> > John
> >
> >
> >> -Original Message-
> >> From: gene heskett [mailto:ghesk...@shentel.net]
> >> Sent: July 29, 2023 9:02 PM
> >> To: emc-users@lists.sourceforge.net
> >> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> >>
> >> On 7/29/23 22:36, John Dammeyer wrote:
> >>> Here's my solution.  Drilled and milled 0.065" aluminum.  Two counter
> > sunk
> >>> holes in the back.  The modified flat head screws epoxied in serving
as
> >>> threaded studs.  Then followed standard CUI installation and alignment
> >>> instructions.
> >>>
> >>> Now to interface to it and write software to capture the motion and
> >> position
> >>> John
> >>>
> >> Just one question John, is that encoder optical, or hall effect?
> >> Optical is real time, hall effect is not.
> >>>
>  -Original Message-
>  From: Curtis Dutton [mailto:curtd...@gmail.com]
>  Sent: June 26, 2023 6:28 PM
>  To: Enhanced Machine Controller (EMC)
>  Subject: Re: [Emc-users] Drilling holes in the back of a stepper
motor
> 
>  On a past life before I started using servos I had attached encoders
to
> > my
>  steppers to stop the machine when steps were missed. I used us
digital
>  encoders that came with adhesive backed mounts from the factory.
> They
>  

Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 7/30/23 00:12, John Dammeyer wrote:

Hi Gene,
Best answered with the data sheet.
https://www.cuidevices.com/product/resource/amt11.pdf

A Capacitative device. Not a hall effect. The capacitative may be faster 
than a hall.  The reason I'm anti hall is the time lag in the hall world 
due to the time it takes to do the A/D conversions, which in turn means 
the hall encoded setup moves in jerks depending on the speed of that 
conversion. The 42C series of small motors, seen as ideal for a 3d 
printer, are a disaster because they don't move step by step but jerk by 
jerk, frequency of jerk determined to the speed of the A/D. Optical can 
determine where the motor is and which direction its turning from any 
edge of either A or B signals. At sufficient microstep divisors they can 
move quite pretty smoothly. I'd assume this time lag in less for the 
capacitative, but at the same time there is the Nyquist effect but the 
capacitative conversion is simpler, but the serial output still enforces 
a lag in the data stream. Only optical, which at higher and fixed 
resolutions is instant. The question remains then "is capacitative fast 
enough".  And that IDK. The 115 kilobaud output says no to me.  That 
alone would make me go shopping for a ABI encoder.


But I'm known to be picky. That's an optical $22 Omron 1000 ppr on the 
back shaft of the 1 hp in my g0704. With the gear ratio being 
switchable, and that encoder rated for 6k revs, but I watch spindle revs 
in the tach display. Top spindle is 3k revs. So times a hair over 7100, 
its seeing motor revs of nearly 21k revs at full song and not missing a 
beat for about 5 years now. Scale for high gear is a hair over 7100 per 
spindle rev.  I don't use the index, that is generated by a screw glued 
to the spindle going by an ATS-667 hall effect. That has its own 
direction problem I'm not smart enough to fix.   Someday...



Not cheap in Canadian $.
https://www.digikey.ca/en/products/detail/cui-devices/AMT113Q-V/4835229

John



-Original Message-
From: gene heskett [mailto:ghesk...@shentel.net]
Sent: July 29, 2023 9:02 PM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On 7/29/23 22:36, John Dammeyer wrote:

Here's my solution.  Drilled and milled 0.065" aluminum.  Two counter

sunk

holes in the back.  The modified flat head screws epoxied in serving as
threaded studs.  Then followed standard CUI installation and alignment
instructions.

Now to interface to it and write software to capture the motion and

position

John


Just one question John, is that encoder optical, or hall effect?
Optical is real time, hall effect is not.



-Original Message-
From: Curtis Dutton [mailto:curtd...@gmail.com]
Sent: June 26, 2023 6:28 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On a past life before I started using servos I had attached encoders to

my

steppers to stop the machine when steps were missed. I used us digital
encoders that came with adhesive backed mounts from the factory. They
worked swimmingly. I still have one in the "spare parts" room. The

encoder

is still securely attached over 10 years later. "double sided tape"
essentially woked very well.

On Mon, Jun 26, 2023, 3:11 PM Todd Zuercher



wrote:


I was just about to suggest gluing the thing on.  You beat me to it.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Roland Jollivet 
Sent: Monday, June 26, 2023 1:17 PM
To: Enhanced Machine Controller (EMC) 
us...@lists.sourceforge.net>

Subject: [Emc-users] Drilling holes in the back of a stepper motor

[EXTERNAL EMAIL] Be sure links are safe.

You have such a large flat surface area there. Design an encoder mount
plate of similar size where the end result is also has a flat surface.

Rough and clean the back of the motor up, then use a decent

polyurethane

adhesive to bond it on. During the setup you could use a jig to keep

it

concentric with the shaft.
Design it in such a way that you can still replace the encoder if need

be.


Roland




On Sun, 25 Jun 2023 at 05:31, John Dammeyer



wrote:


I want to add an encoder onto the back of this stepper motor.  I can
install either a US Digital or a CUI since both mounting flanges can
extend out near the edges of the back mounting plate.



Is there any reason I can't clamp the motor in a vice and pop in two

holes

and tap them with a bottom tap at the spacing of the mounting flange?

John



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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Hi Gene,
Best answered with the data sheet.
https://www.cuidevices.com/product/resource/amt11.pdf

Not cheap in Canadian $.
https://www.digikey.ca/en/products/detail/cui-devices/AMT113Q-V/4835229

John


> -Original Message-
> From: gene heskett [mailto:ghesk...@shentel.net]
> Sent: July 29, 2023 9:02 PM
> To: emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> 
> On 7/29/23 22:36, John Dammeyer wrote:
> > Here's my solution.  Drilled and milled 0.065" aluminum.  Two counter
sunk
> > holes in the back.  The modified flat head screws epoxied in serving as
> > threaded studs.  Then followed standard CUI installation and alignment
> > instructions.
> >
> > Now to interface to it and write software to capture the motion and
> position
> > John
> >
> Just one question John, is that encoder optical, or hall effect?
> Optical is real time, hall effect is not.
> >
> >> -Original Message-
> >> From: Curtis Dutton [mailto:curtd...@gmail.com]
> >> Sent: June 26, 2023 6:28 PM
> >> To: Enhanced Machine Controller (EMC)
> >> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> >>
> >> On a past life before I started using servos I had attached encoders to
my
> >> steppers to stop the machine when steps were missed. I used us digital
> >> encoders that came with adhesive backed mounts from the factory. They
> >> worked swimmingly. I still have one in the "spare parts" room. The
> encoder
> >> is still securely attached over 10 years later. "double sided tape"
> >> essentially woked very well.
> >>
> >> On Mon, Jun 26, 2023, 3:11 PM Todd Zuercher
> 
> >> wrote:
> >>
> >>> I was just about to suggest gluing the thing on.  You beat me to it.
> >>>
> >>> Todd Zuercher
> >>> P. Graham Dunn Inc.
> >>> 630 Henry Street
> >>> Dalton, Ohio 44618
> >>> Phone:  (330)828-2105ext. 2031
> >>>
> >>> -Original Message-
> >>> From: Roland Jollivet 
> >>> Sent: Monday, June 26, 2023 1:17 PM
> >>> To: Enhanced Machine Controller (EMC)  >> us...@lists.sourceforge.net>
> >>> Subject: [Emc-users] Drilling holes in the back of a stepper motor
> >>>
> >>> [EXTERNAL EMAIL] Be sure links are safe.
> >>>
> >>> You have such a large flat surface area there. Design an encoder mount
> >>> plate of similar size where the end result is also has a flat surface.
> >>>
> >>> Rough and clean the back of the motor up, then use a decent
> polyurethane
> >>> adhesive to bond it on. During the setup you could use a jig to keep
it
> >>> concentric with the shaft.
> >>> Design it in such a way that you can still replace the encoder if need
> > be.
> >>>
> >>> Roland
> >>>
> >>>
> >>>
> >>>
> >>> On Sun, 25 Jun 2023 at 05:31, John Dammeyer
> 
> >>> wrote:
> >>>
>  I want to add an encoder onto the back of this stepper motor.  I can
>  install either a US Digital or a CUI since both mounting flanges can
>  extend out near the edges of the back mounting plate.
> 
> 
> 
>  Is there any reason I can't clamp the motor in a vice and pop in two
> >>> holes
>  and tap them with a bottom tap at the spacing of the mounting flange?
> 
>  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
> >>>
> >>>
> >>> ___
> >>> 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
> 
> 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, 1940)
> If we desire respect for the law, we must first make the law respectable.
>   - Louis D. Brandeis
> Genes Web page 
> 
> 
> 
> ___
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 7/29/23 22:36, John Dammeyer wrote:

Here's my solution.  Drilled and milled 0.065" aluminum.  Two counter sunk
holes in the back.  The modified flat head screws epoxied in serving as
threaded studs.  Then followed standard CUI installation and alignment
instructions.

Now to interface to it and write software to capture the motion and position
John

Just one question John, is that encoder optical, or hall effect? 
Optical is real time, hall effect is not.



-Original Message-
From: Curtis Dutton [mailto:curtd...@gmail.com]
Sent: June 26, 2023 6:28 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On a past life before I started using servos I had attached encoders to my
steppers to stop the machine when steps were missed. I used us digital
encoders that came with adhesive backed mounts from the factory. They
worked swimmingly. I still have one in the "spare parts" room. The encoder
is still securely attached over 10 years later. "double sided tape"
essentially woked very well.

On Mon, Jun 26, 2023, 3:11 PM Todd Zuercher 
wrote:


I was just about to suggest gluing the thing on.  You beat me to it.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Roland Jollivet 
Sent: Monday, June 26, 2023 1:17 PM
To: Enhanced Machine Controller (EMC) 
us...@lists.sourceforge.net>

Subject: [Emc-users] Drilling holes in the back of a stepper motor

[EXTERNAL EMAIL] Be sure links are safe.

You have such a large flat surface area there. Design an encoder mount
plate of similar size where the end result is also has a flat surface.

Rough and clean the back of the motor up, then use a decent polyurethane
adhesive to bond it on. During the setup you could use a jig to keep it
concentric with the shaft.
Design it in such a way that you can still replace the encoder if need

be.


Roland




On Sun, 25 Jun 2023 at 05:31, John Dammeyer 
wrote:


I want to add an encoder onto the back of this stepper motor.  I can
install either a US Digital or a CUI since both mounting flanges can
extend out near the edges of the back mounting plate.



Is there any reason I can't clamp the motor in a vice and pop in two

holes

and tap them with a bottom tap at the spacing of the mounting flange?

John



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



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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, 1940)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 



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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Here's my solution.  Drilled and milled 0.065" aluminum.  Two counter sunk
holes in the back.  The modified flat head screws epoxied in serving as
threaded studs.  Then followed standard CUI installation and alignment
instructions.

Now to interface to it and write software to capture the motion and position
John


> -Original Message-
> From: Curtis Dutton [mailto:curtd...@gmail.com]
> Sent: June 26, 2023 6:28 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> 
> On a past life before I started using servos I had attached encoders to my
> steppers to stop the machine when steps were missed. I used us digital
> encoders that came with adhesive backed mounts from the factory. They
> worked swimmingly. I still have one in the "spare parts" room. The encoder
> is still securely attached over 10 years later. "double sided tape"
> essentially woked very well.
> 
> On Mon, Jun 26, 2023, 3:11 PM Todd Zuercher 
> wrote:
> 
> > I was just about to suggest gluing the thing on.  You beat me to it.
> >
> > Todd Zuercher
> > P. Graham Dunn Inc.
> > 630 Henry Street
> > Dalton, Ohio 44618
> > Phone:  (330)828-2105ext. 2031
> >
> > -Original Message-
> > From: Roland Jollivet 
> > Sent: Monday, June 26, 2023 1:17 PM
> > To: Enhanced Machine Controller (EMC)  us...@lists.sourceforge.net>
> > Subject: [Emc-users] Drilling holes in the back of a stepper motor
> >
> > [EXTERNAL EMAIL] Be sure links are safe.
> >
> > You have such a large flat surface area there. Design an encoder mount
> > plate of similar size where the end result is also has a flat surface.
> >
> > Rough and clean the back of the motor up, then use a decent polyurethane
> > adhesive to bond it on. During the setup you could use a jig to keep it
> > concentric with the shaft.
> > Design it in such a way that you can still replace the encoder if need
be.
> >
> > Roland
> >
> >
> >
> >
> > On Sun, 25 Jun 2023 at 05:31, John Dammeyer 
> > wrote:
> >
> > > I want to add an encoder onto the back of this stepper motor.  I can
> > > install either a US Digital or a CUI since both mounting flanges can
> > > extend out near the edges of the back mounting plate.
> > >
> > >
> > >
> > > Is there any reason I can't clamp the motor in a vice and pop in two
> > holes
> > > and tap them with a bottom tap at the spacing of the mounting flange?
> > >
> > > 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
> >
> >
> > ___
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> 
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[Curtis Dutton]

On a past life before I started using servos I had attached encoders to my
steppers to stop the machine when steps were missed. I used us digital
encoders that came with adhesive backed mounts from the factory. They
worked swimmingly. I still have one in the "spare parts" room. The encoder
is still securely attached over 10 years later. "double sided tape"
essentially woked very well.

On Mon, Jun 26, 2023, 3:11 PM Todd Zuercher  wrote:

> I was just about to suggest gluing the thing on.  You beat me to it.
>
> Todd Zuercher
> P. Graham Dunn Inc.
> 630 Henry Street
> Dalton, Ohio 44618
> Phone:  (330)828-2105ext. 2031
>
> -Original Message-
> From: Roland Jollivet 
> Sent: Monday, June 26, 2023 1:17 PM
> To: Enhanced Machine Controller (EMC) 
> Subject: [Emc-users] Drilling holes in the back of a stepper motor
>
> [EXTERNAL EMAIL] Be sure links are safe.
>
> You have such a large flat surface area there. Design an encoder mount
> plate of similar size where the end result is also has a flat surface.
>
> Rough and clean the back of the motor up, then use a decent polyurethane
> adhesive to bond it on. During the setup you could use a jig to keep it
> concentric with the shaft.
> Design it in such a way that you can still replace the encoder if need be.
>
> Roland
>
>
>
>
> On Sun, 25 Jun 2023 at 05:31, John Dammeyer 
> wrote:
>
> > I want to add an encoder onto the back of this stepper motor.  I can
> > install either a US Digital or a CUI since both mounting flanges can
> > extend out near the edges of the back mounting plate.
> >
> >
> >
> > Is there any reason I can't clamp the motor in a vice and pop in two
> holes
> > and tap them with a bottom tap at the spacing of the mounting flange?
> >
> > John
> >
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
> ___
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>
>
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[Todd Zuercher]

I was just about to suggest gluing the thing on.  You beat me to it.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Roland Jollivet 
Sent: Monday, June 26, 2023 1:17 PM
To: Enhanced Machine Controller (EMC) 
Subject: [Emc-users] Drilling holes in the back of a stepper motor

[EXTERNAL EMAIL] Be sure links are safe.

You have such a large flat surface area there. Design an encoder mount plate of 
similar size where the end result is also has a flat surface.

Rough and clean the back of the motor up, then use a decent polyurethane 
adhesive to bond it on. During the setup you could use a jig to keep it 
concentric with the shaft.
Design it in such a way that you can still replace the encoder if need be.

Roland




On Sun, 25 Jun 2023 at 05:31, John Dammeyer  wrote:

> I want to add an encoder onto the back of this stepper motor.  I can
> install either a US Digital or a CUI since both mounting flanges can
> extend out near the edges of the back mounting plate.
>
>
>
> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?
>
> John
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Photos would be handy here.
John

-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com] 
Sent: June 26, 2023 9:59 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

I�m working on the same kind of thing. I want to add an encoder to a BLDC drone 
motor and we don�t have much shaft length at all.

The design �secret� is to realize that you do NOT need a plate or any material 
at all between the motor and the encoder.  You can support the encoder from the 
rear.

Make a 5-sided box housing that fits over the end of the motor and the encoder 
attaches to the inside of the box and also to the extended shaft.  he encoder 
does not even need to touch the motor housing.  Or maybe you only use locator 
pins in very shallow holes in the motor.

3D printers and CAD software make this made of complex parts easy.  It is easy 
to p3d print blind threaded holes to mount the encoder from the inside of the 
enclosure, then you screw the enclosure box with mounted encoder to the back of 
the motor.   Finally to tighten the set scre to the motor shaft. (Leave a hole 
for a hex wrench.  Then a pan head screw closes the access hole.

In my case I have the motor mounted inside two parts that assemble like a 
clamshell. Parts go into the shells then you assemble the shells.




> On Jun 26, 2023, at 12:28 AM, John Dammeyer  wrote:
> 
> Unfortunately access to the assembly is required to center things and then 
> tighten screws.  Nice as an enclosure might be it wouldn't solve the problem
> 
> What I have done, since I don't have the press in type screws, is with a 
> countersunk 4-40 flat head I used my little DB200 lathe to remove some of the 
> countersink taper.  I think gluing this into a 0.055" thick mounting plate 
> will prevent them from turning and also then fit the 4 mount locations along 
> with holding down the encoder.
> 
> Photo shows the screws and screen capture the plate I drew up.  I'll use 4x 
> 3mm screws to go into the 4 corners of the motor.  The two 4-40 threaded 
> studs (in effect) will come up through the other two holes.  If the corner 
> holes are large enough there should be enough play to be able to center the 
> disk in the encoder.
> 
> The down side is I've totally forgotten how to use my tool height setter and 
> touch probe to run the G-Code I've now created for profiling the plate.  
> Should have written myself better directions.
> 
> Sigh...
> John
> 
> 
> -Original Message-
> From: Gregg Eshelman via Emc-users [mailto:emc-users@lists.sourceforge.net] 
> Sent: June 25, 2023 11:22 PM
> To: Enhanced Machine Controller (EMC)
> Cc: Gregg Eshelman
> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> 
> Make covers that fit over and hold the encoder. Snap the encoder into the 
> inside of the cover, and the corners of the cover have holes to put screws 
> into the existing holes in the motor end cap. This would have the benefit of 
> protecting the encoder and the end of the motor shaft.
> 
> 
> On Sunday, June 25, 2023 at 03:33:26 AM MDT, John Dammeyer 
>  wrote: 
> 
> The problem is the rear shaft isn't that long.? 
> 
> I went through the process of considering an adaptor plate that fastened to 
> the 4 holes.? ? There may be a fancy way of making a thick plate with a 
> thinned area just for the encoder mount.? But it would have to have a stud 
> protruding away from the back and then a nut.? The plate can't be thick 
> enough to hold both the encoder and threads for screws and still have the 
> encoder disk mount to the back shaft.
> 
> The alternative would be to press fit on a shaft extension and then use the 
> stepper motor to turn the extension to be symmetrical with the axis of the 
> motor shaft.? Then I could use a thicker mounting plate.
> 
> Or, given that the motor drives a 25:1 planetary gear and I'm really only 
> interested in tracking motor revolutions and detecting stall conditions 
> (hence quadrature) I could likely get away with a custom disk and some 
> slotted sensors too.? Also more complicated to build.? 
> 
> Trying to keep it simple and the easiest is to have the encoder screw 
> directly to the back of the motor.? However with StepperOnline motor by the 
> time it's here in Cdn $ it's over $100.? So I can take the risk and drill 
> holes in the back.? Or get creative with other approaches.
> John
> 
> 
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[Emc-users] Drilling holes in the back of a stepper motor

[Roland Jollivet]

You have such a large flat surface area there. Design an encoder mount
plate of similar size where the end result is also has a flat surface.

Rough and clean the back of the motor up, then use a decent polyurethane
adhesive to bond it on. During the setup you could use a jig to keep it
concentric with the shaft.
Design it in such a way that you can still replace the encoder if need be.

Roland




On Sun, 25 Jun 2023 at 05:31, John Dammeyer  wrote:

> I want to add an encoder onto the back of this stepper motor.  I can
> install
> either a US Digital or a CUI since both mounting flanges can extend out
> near
> the edges of the back mounting plate.
>
>
>
> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?
>
> John
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

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Re: [Emc-users] Drilling holes in the back of a stepper motor

[Chris Albertson]

I’m working on the same kind of thing. I want to add an encoder to a BLDC drone 
motor and we don’t have much shaft length at all.

The design “secret” is to realize that you do NOT need a plate or any material 
at all between the motor and the encoder.  You can support the encoder from the 
rear.

Make a 5-sided box housing that fits over the end of the motor and the encoder 
attaches to the inside of the box and also to the extended shaft.  he encoder 
does not even need to touch the motor housing.  Or maybe you only use locator 
pins in very shallow holes in the motor.

3D printers and CAD software make this made of complex parts easy.  It is easy 
to p3d print blind threaded holes to mount the encoder from the inside of the 
enclosure, then you screw the enclosure box with mounted encoder to the back of 
the motor.   Finally to tighten the set scre to the motor shaft. (Leave a hole 
for a hex wrench.  Then a pan head screw closes the access hole.

In my case I have the motor mounted inside two parts that assemble like a 
clamshell. Parts go into the shells then you assemble the shells.




> On Jun 26, 2023, at 12:28 AM, John Dammeyer  wrote:
> 
> Unfortunately access to the assembly is required to center things and then 
> tighten screws.  Nice as an enclosure might be it wouldn't solve the problem
> 
> What I have done, since I don't have the press in type screws, is with a 
> countersunk 4-40 flat head I used my little DB200 lathe to remove some of the 
> countersink taper.  I think gluing this into a 0.055" thick mounting plate 
> will prevent them from turning and also then fit the 4 mount locations along 
> with holding down the encoder.
> 
> Photo shows the screws and screen capture the plate I drew up.  I'll use 4x 
> 3mm screws to go into the 4 corners of the motor.  The two 4-40 threaded 
> studs (in effect) will come up through the other two holes.  If the corner 
> holes are large enough there should be enough play to be able to center the 
> disk in the encoder.
> 
> The down side is I've totally forgotten how to use my tool height setter and 
> touch probe to run the G-Code I've now created for profiling the plate.  
> Should have written myself better directions.
> 
> Sigh...
> John
> 
> 
> -Original Message-
> From: Gregg Eshelman via Emc-users [mailto:emc-users@lists.sourceforge.net] 
> Sent: June 25, 2023 11:22 PM
> To: Enhanced Machine Controller (EMC)
> Cc: Gregg Eshelman
> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> 
> Make covers that fit over and hold the encoder. Snap the encoder into the 
> inside of the cover, and the corners of the cover have holes to put screws 
> into the existing holes in the motor end cap. This would have the benefit of 
> protecting the encoder and the end of the motor shaft.
> 
> 
> On Sunday, June 25, 2023 at 03:33:26 AM MDT, John Dammeyer 
>  wrote: 
> 
> The problem is the rear shaft isn't that long.� 
> 
> I went through the process of considering an adaptor plate that fastened to 
> the 4 holes.� � There may be a fancy way of making a thick plate with a 
> thinned area just for the encoder mount.� But it would have to have a stud 
> protruding away from the back and then a nut.� The plate can't be thick 
> enough to hold both the encoder and threads for screws and still have the 
> encoder disk mount to the back shaft.
> 
> The alternative would be to press fit on a shaft extension and then use the 
> stepper motor to turn the extension to be symmetrical with the axis of the 
> motor shaft.� Then I could use a thicker mounting plate.
> 
> Or, given that the motor drives a 25:1 planetary gear and I'm really only 
> interested in tracking motor revolutions and detecting stall conditions 
> (hence quadrature) I could likely get away with a custom disk and some 
> slotted sensors too.� Also more complicated to build.� 
> 
> Trying to keep it simple and the easiest is to have the encoder screw 
> directly to the back of the motor.� However with StepperOnline motor by the 
> time it's here in Cdn $ it's over $100.� So I can take the risk and drill 
> holes in the back.� Or get creative with other approaches.
> John
> 
> 
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[Gregg Eshelman via Emc-users]

Make covers that fit over and hold the encoder. Snap the encoder into the 
inside of the cover, and the corners of the cover have holes to put screws into 
the existing holes in the motor end cap. This would have the benefit of 
protecting the encoder and the end of the motor shaft.


On Sunday, June 25, 2023 at 03:33:26 AM MDT, John Dammeyer 
 wrote: 

The problem is the rear shaft isn't that long.  

I went through the process of considering an adaptor plate that fastened to the 
4 holes.    There may be a fancy way of making a thick plate with a thinned 
area just for the encoder mount.  But it would have to have a stud protruding 
away from the back and then a nut.  The plate can't be thick enough to hold 
both the encoder and threads for screws and still have the encoder disk mount 
to the back shaft.

The alternative would be to press fit on a shaft extension and then use the 
stepper motor to turn the extension to be symmetrical with the axis of the 
motor shaft.  Then I could use a thicker mounting plate.

Or, given that the motor drives a 25:1 planetary gear and I'm really only 
interested in tracking motor revolutions and detecting stall conditions (hence 
quadrature) I could likely get away with a custom disk and some slotted sensors 
too.  Also more complicated to build.  

Trying to keep it simple and the easiest is to have the encoder screw directly 
to the back of the motor.  However with StepperOnline motor by the time it's 
here in Cdn $ it's over $100.  So I can take the risk and drill holes in the 
back.  Or get creative with other approaches.
John


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 6/25/23 12:23, John Dammeyer wrote:

Gene,
I use Alibre.  Happy with that although not renewing support this year.
John


I looked at it, quite a few yeas ago now, but the cost to get a full copy
of it discouraged me.

The sample was too limited plus I just couldn't get my technical head 
around it.  When I stumbled over OpenSCAD in about 2019, I was amazed at 
how simple it was to actually make something with it. Not at all usable 
with linuxcnc but absolutely the bees knees for additive stuff. I've now 
made 4 versions of this board mount with the last revision being .1mm 
smaller boltholes to the 3mm screws self thread with just a red ones 
deeper thread engagement, that will work but I need at least 2 of them 
so the one on the printer now will have 2.9mm boltholes. Made with PETG, 
much more resilient than PLA, and a 40C higher temp tolerance, should 
last till forever or the nearest star, our sun goes supernova. Outlast 
me for sure. The finished ones will get a dab of shoe goo near each 
corner and stuck inside the bases of 2 or 3 dead printers here. To mount 
much more capable printer controllers.


Take care & stay well, John.
[...]
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, 1940)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 



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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Alan,
That's not such a bad idea used in combination with Gene's idea of 3D
printing.  I don't think this stepper motor will get very warm but generally
mounting a stepper onto PLA is never a good idea since it gets soft at a low
temperature.

But maybe using ABS would match the temperature spec of the plastic base
used by CUI.  Then essentially build two ears that reach the outer mounting
holes and match the curves on the ears of the CUI mount.  Connect the two
with JB-Weld over a linear distance of an inch or so.

I'll give that some thought too.

John


-Original Message-
From: Alan Condit via Emc-users [mailto:emc-users@lists.sourceforge.net] 
Sent: June 25, 2023 7:33 AM
To: EMC-Users
Cc: Alan Condit
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

John,

I have used JB-weld to rebuild plastic parts (commercially manufactured) so
that I could drill and tap where a threaded support had pulled out. I just
used clay to build a dam around the area that I wanted to fill with epoxy.
Then after setting I drilled and tapped the new support. It was much
stronger than the original part.

Alan

> From: "John Dammeyer" 
> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> Date: June 25, 2023 at 1:19:01 AM CDT
> To: "'Enhanced Machine Controller \(EMC\)'"

> 
> 
> Some of the stepper motors available from SteppersOnline show two pairs of
> screw holes near the edges.  And you are correct.  Youtube videos of
stepper
> dismantling show that it's pretty thin near the edges and the windings are
> really close.
> However, I've read that once you dismantle a stepper motor it loses some
of
> the magnetism.   That they are magnetised with much higher pulses of
current
> when the motor is assembled.  But that might also be an urban legend.
> Anyway, the back end also has the motor leads coming out so pulling it
apart
> may also damage it.  Or not.  Easier to just order a new motor perhaps.
> John


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Thanks Andy,
I think I might be able to use 20g plate but anything thicker results in 
partial engagement of the encoder disk hub.  Again, it may not be that big a 
deal.  Going to try something like that today.
John

-Original Message-
From: andy pugh [mailto:bodge...@gmail.com] 
Sent: June 25, 2023 2:52 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On Sun, 25 Jun 2023 at 10:36, John Dammeyer  wrote:

> The plate can't be thick enough to hold both the encoder and threads for 
> screws and still have the encoder disk mount to the back shaft.

I would use countersunk screws from the motor side, with nuts to hold
the encoder to the plate, then bolt the plate to the motor.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
� George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Thanks for the ideas Gene.
John

-Original Message-
From: gene heskett [mailto:ghesk...@shentel.net] 
Sent: June 25, 2023 7:25 AM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On 6/25/23 05:32, John Dammeyer wrote:
> The problem is the rear shaft isn't that long.
> 
> I went through the process of considering an adaptor plate that fastened
to the 4 holes.There may be a fancy way of making a thick plate with a
thinned area just for the encoder mount.  But it would have to have a stud
protruding away from the back and then a nut.  The plate can't be thick
enough to hold both the encoder and threads for screws and still have the
encoder disk mount to the back shaft.
> 
> The alternative would be to press fit on a shaft extension and then use
the stepper motor to turn the extension to be symmetrical with the axis of
the motor shaft.   Then I could use a thicker mounting plate.
> 
I faced a similar problem when I moved the homemade optical encoder on 
my g0704 mill from the spindle to the motor, which had no back shaft at 
all as it sits flush in the rear housing cap of that 1hp motor.  So a 
very carefully drilled and tapped for about a 3mm screw in the motor 
shaft and made a 20mm long brass extension. Then put the elastomer 
coupling that came with the 1000 line 22 dollar Omron encoder on 
standoffs drilled into the decorator cover with over sized holes so I 
could align it as best I could,  It ran that way for about a year, but 
demolished the coupling eventually, so now for around 5 years the 
coupling has been two layers of heat shrink tubing shrunk on in place of 
the coupling. I've not had to replace either the heat shrink or the 
encoder since.  With that much higher resolution, quantization noise is 
gone, Pgains in the motor control PID can be as high as 40 w/o oscillation.

Of course theres some hal trickery to make it all just work, like 
changing gears with the motor running. I have 2 tally switches on the 
gearshift knob that are only activated if the thing is fully engaged in 
one or the other gears. By way of a mux4 they switch the scale so the 
spindle rpm tach is dead accurate but if its not fully engaged, neither 
switch is true, so the mux4 feeds a tickle signal to the motor so the 
motor is turning around 50 rpm between gears, so I don't have to grab 
the spindle and turn it till the gears engage.

I can be spinning at 1500 revs in low gear, reach up and crank the knob, 
the motor is down to a crawl as soon as the knob moves a couple degrees, 
the motor then engages the other gear w/o hesitation, as when the tally 
switch makes for that gear, whatever speed was selected is restored and 
the tach says 3000 revs. Motor response is in the 100 millisecond range,

I can't turn the knob anywhere near fast enough to cause a gear clash. 
Works in fwd and rev from m3 to m4 or for rigid tapping in 2 maybe 3 
hundred milliseconds. Some of that key is the power supply for the motor 
is about 125 volts, AND Jon Elson's pwm-servo controller being a full 4 
quadrant controller, so when the motor is slowed that fast, the psu 
voltage peaks at around 170 because the motors spinning energy is sucked 
out of the motor and back into the psu, charging it up to around 30 
volts more than the capacitors voltage ratings, but this over voltage is 
then used up by feeding it back into the motor to speed it up in the 
other direction.  So that 90 volt rated motor is being drasticly abused.

And it is still running on the oem brushes yet in 2023. Instant horse 
power for rigid tapping is at least 3hp. 9.7 amps is its FLA, but Jon 
E's servo current limits at 18 amps. The PID is stiff enough the 
squeaking of the iron in the motor is my only indication the load is too 
high.

> Or, given that the motor drives a 25:1 planetary gear and I'm really only
interested in tracking motor revolutions and detecting stall conditions
(hence quadrature) I could likely get away with a custom disk and some
slotted sensors too.  Also more complicated to build.

And likely full of quantization noise. I thought the bearings were going 
out of the gears from that noise before I changed the encoder. Now it 
runs silently below 500 spindle revs.
> 
> Trying to keep it simple and the easiest is to have the encoder screw
directly to the back of the motor.  However with StepperOnline motor by the
time it's here in Cdn $ it's over $100.  So I can take the risk and drill
holes in the back.  Or get creative with other approaches.

Precisely why I suggested the 3d printer solution. An Omron 1000 line 
encoder will be longer than your pix'd encoders but for $22 USD and some 
time to print the adapter stuff, be a very workable solution. You can 
essentially duplicate the new stepper/servo's by just changing the 
controller but its still a bit high, the Hanpose cl57 controller is 
around $80/copy from aliexpress if you can tolerate the shipping delay.

The huge advantage of 

Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Thanks Marcus for the ideas.  Front of the motor drives a 25:1 planetary 
reduction.  It has a larger shaft and 3/8" socket adaptor.  This is all for the 
power draw bar.
John

-Original Message-
From: marcus.bow...@visible.eclipse.co.uk 
[mailto:marcus.bow...@visible.eclipse.co.uk] 
Sent: June 25, 2023 2:48 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On 2023-06-25 10:33, andrew beck wrote:
> Adapter plate sounds easiest to me
> 

+1 for an adapter plate; its much safer and also more versatile.
Have you thought of mounting the encoder parallel to the stepper, and 
using a small pulley and belt between the shafts. That might give you 
more mounting options.

Another option would be if the motor have long bolts running through 
from front to back, those could be extended to hold an adapter plate.

Or could the encoder be driven off the front of the motor, using the 
existing belt (if your setup uses one).

Marcus





> On Sun, 25 Jun 2023, 21:01 andy pugh,  wrote:
> 
>> On Sun, 25 Jun 2023 at 04:31, John Dammeyer 
>> wrote:
>> 
>> > Is there any reason I can't clamp the motor in a vice and pop in two
>> holes
>> > and tap them with a bottom tap at the spacing of the mounting flange?
>> 
>> I have done it in-situ, but there really isn't all that much metal in
>> there.
>> 
>> I think pulling the back cover off (leaving the rotor in place) and
>> choosing your mounting point carefully would probably be best.
>> 
>> Or, as Gene says, use the existing holes, very short screws, and an
>> adaptor plate.
>> 
>> --
>> atp
>> "A motorcycle is a bicycle with a pandemonium attachment and is
>> designed for the especial use of mechanical geniuses, daredevils and
>> lunatics."
>> � George Fitch, Atlanta Constitution Newspaper, 1912
>> 
>> 
>> ___
>> Emc-users mailing list
>> Emc-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/emc-users
>> 
> 
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Actually if made the mounting plate out of brass I could soft solder the flat 
head screws.

-Original Message-
From: TJoseph Powderly [mailto:tjt...@gmail.com] 
Sent: June 25, 2023 6:30 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

drill hole in and tap
or
glue screws on exterior, thread side out ?  ;=}
i read the force would be snall

outside the box   literally
tomp

On Sun, Jun 25, 2023 at 10:31�AM John Dammeyer  wrote:
>
> I want to add an encoder onto the back of this stepper motor.  I can install
> either a US Digital or a CUI since both mounting flanges can extend out near
> the edges of the back mounting plate.
>
>
>
> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?
>
> John
>
>
>
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Gene,
I use Alibre.  Happy with that although not renewing support this year.
John

-Original Message-
From: gene heskett [mailto:ghesk...@shentel.net] 
Sent: June 25, 2023 5:58 AM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On 6/25/23 04:59, andy pugh wrote:
> On Sun, 25 Jun 2023 at 04:31, John Dammeyer 
wrote:
> 
>> Is there any reason I can't clamp the motor in a vice and pop in two
holes
>> and tap them with a bottom tap at the spacing of the mounting flange?
> 
> I have done it in-situ, but there really isn't all that much metal in
there.
> 
> I think pulling the back cover off (leaving the rotor in place) and
> choosing your mounting point carefully would probably be best.
> 
> Or, as Gene says, use the existing holes, very short screws, and an
> adaptor plate.
> 
The advantage there is that on your test assembly, you'll likely find 
something that needs changed to make it fit really well, and the 
OpenSCAD edit of one or two vars, thru cura and feeding the gcode from 
cura to the printer for a corrected copy is a 5 minute job. During which 
time you can take a nap or do other productive work.  At my age, the nap 
often wins. ;o)> Keeps me out of the bars too dontcha know.

Tace care and stay well 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, 1940)
If we desire respect for the law, we must first make the law respectable.
  - Louis D. Brandeis
Genes Web page 



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Re: [Emc-users] Drilling holes in the back of a stepper motor

[Alan Condit via Emc-users]

John,

I have used JB-weld to rebuild plastic parts (commercially manufactured) so 
that I could drill and tap where a threaded support had pulled out. I just used 
clay to build a dam around the area that I wanted to fill with epoxy. Then 
after setting I drilled and tapped the new support. It was much stronger than 
the original part.

Alan

> From: "John Dammeyer" 
> Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor
> Date: June 25, 2023 at 1:19:01 AM CDT
> To: "'Enhanced Machine Controller \(EMC\)'" 
> 
> 
> Some of the stepper motors available from SteppersOnline show two pairs of
> screw holes near the edges.  And you are correct.  Youtube videos of stepper
> dismantling show that it's pretty thin near the edges and the windings are
> really close.
> However, I've read that once you dismantle a stepper motor it loses some of
> the magnetism.   That they are magnetised with much higher pulses of current
> when the motor is assembled.  But that might also be an urban legend.
> Anyway, the back end also has the motor leads coming out so pulling it apart
> may also damage it.  Or not.  Easier to just order a new motor perhaps.
> John


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 6/25/23 05:32, John Dammeyer wrote:

The problem is the rear shaft isn't that long.

I went through the process of considering an adaptor plate that fastened to the 
4 holes.There may be a fancy way of making a thick plate with a thinned 
area just for the encoder mount.  But it would have to have a stud protruding 
away from the back and then a nut.  The plate can't be thick enough to hold 
both the encoder and threads for screws and still have the encoder disk mount 
to the back shaft.

The alternative would be to press fit on a shaft extension and then use the 
stepper motor to turn the extension to be symmetrical with the axis of the 
motor shaft.   Then I could use a thicker mounting plate.

I faced a similar problem when I moved the homemade optical encoder on 
my g0704 mill from the spindle to the motor, which had no back shaft at 
all as it sits flush in the rear housing cap of that 1hp motor.  So a 
very carefully drilled and tapped for about a 3mm screw in the motor 
shaft and made a 20mm long brass extension. Then put the elastomer 
coupling that came with the 1000 line 22 dollar Omron encoder on 
standoffs drilled into the decorator cover with over sized holes so I 
could align it as best I could,  It ran that way for about a year, but 
demolished the coupling eventually, so now for around 5 years the 
coupling has been two layers of heat shrink tubing shrunk on in place of 
the coupling. I've not had to replace either the heat shrink or the 
encoder since.  With that much higher resolution, quantization noise is 
gone, Pgains in the motor control PID can be as high as 40 w/o oscillation.


Of course theres some hal trickery to make it all just work, like 
changing gears with the motor running. I have 2 tally switches on the 
gearshift knob that are only activated if the thing is fully engaged in 
one or the other gears. By way of a mux4 they switch the scale so the 
spindle rpm tach is dead accurate but if its not fully engaged, neither 
switch is true, so the mux4 feeds a tickle signal to the motor so the 
motor is turning around 50 rpm between gears, so I don't have to grab 
the spindle and turn it till the gears engage.


I can be spinning at 1500 revs in low gear, reach up and crank the knob, 
the motor is down to a crawl as soon as the knob moves a couple degrees, 
the motor then engages the other gear w/o hesitation, as when the tally 
switch makes for that gear, whatever speed was selected is restored and 
the tach says 3000 revs. Motor response is in the 100 millisecond range,


I can't turn the knob anywhere near fast enough to cause a gear clash. 
Works in fwd and rev from m3 to m4 or for rigid tapping in 2 maybe 3 
hundred milliseconds. Some of that key is the power supply for the motor 
is about 125 volts, AND Jon Elson's pwm-servo controller being a full 4 
quadrant controller, so when the motor is slowed that fast, the psu 
voltage peaks at around 170 because the motors spinning energy is sucked 
out of the motor and back into the psu, charging it up to around 30 
volts more than the capacitors voltage ratings, but this over voltage is 
then used up by feeding it back into the motor to speed it up in the 
other direction.  So that 90 volt rated motor is being drasticly abused.


And it is still running on the oem brushes yet in 2023. Instant horse 
power for rigid tapping is at least 3hp. 9.7 amps is its FLA, but Jon 
E's servo current limits at 18 amps. The PID is stiff enough the 
squeaking of the iron in the motor is my only indication the load is too 
high.



Or, given that the motor drives a 25:1 planetary gear and I'm really only 
interested in tracking motor revolutions and detecting stall conditions (hence 
quadrature) I could likely get away with a custom disk and some slotted sensors 
too.  Also more complicated to build.


And likely full of quantization noise. I thought the bearings were going 
out of the gears from that noise before I changed the encoder. Now it 
runs silently below 500 spindle revs.


Trying to keep it simple and the easiest is to have the encoder screw directly 
to the back of the motor.  However with StepperOnline motor by the time it's 
here in Cdn $ it's over $100.  So I can take the risk and drill holes in the 
back.  Or get creative with other approaches.


Precisely why I suggested the 3d printer solution. An Omron 1000 line 
encoder will be longer than your pix'd encoders but for $22 USD and some 
time to print the adapter stuff, be a very workable solution. You can 
essentially duplicate the new stepper/servo's by just changing the 
controller but its still a bit high, the Hanpose cl57 controller is 
around $80/copy from aliexpress if you can tolerate the shipping delay.


The huge advantage of the new tech stepper/servo is the motor current is 
controlled by the error, so if the motor is working easy, it runs dead 
cold, you aren't burning up the power meter sitting there with full 
power on a motor regardless of load.


Because 

Re: [Emc-users] Drilling holes in the back of a stepper motor

[TJoseph Powderly]

drill hole in and tap
or
glue screws on exterior, thread side out ?  ;=}
i read the force would be snall

outside the box   literally
tomp

On Sun, Jun 25, 2023 at 10:31 AM John Dammeyer  wrote:
>
> I want to add an encoder onto the back of this stepper motor.  I can install
> either a US Digital or a CUI since both mounting flanges can extend out near
> the edges of the back mounting plate.
>
>
>
> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?
>
> John
>
>
>
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 6/25/23 04:59, andy pugh wrote:

On Sun, 25 Jun 2023 at 04:31, John Dammeyer  wrote:


Is there any reason I can't clamp the motor in a vice and pop in two holes
and tap them with a bottom tap at the spacing of the mounting flange?


I have done it in-situ, but there really isn't all that much metal in there.

I think pulling the back cover off (leaving the rotor in place) and
choosing your mounting point carefully would probably be best.

Or, as Gene says, use the existing holes, very short screws, and an
adaptor plate.

The advantage there is that on your test assembly, you'll likely find 
something that needs changed to make it fit really well, and the 
OpenSCAD edit of one or two vars, thru cura and feeding the gcode from 
cura to the printer for a corrected copy is a 5 minute job. During which 
time you can take a nap or do other productive work.  At my age, the nap 
often wins. ;o)> Keeps me out of the bars too dontcha know.


Tace care and stay well 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, 1940)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 



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Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 6/25/23 04:43, gene heskett wrote:

On 6/24/23 23:29, John Dammeyer wrote:
I want to add an encoder onto the back of this stepper motor.  I can 
install
either a US Digital or a CUI since both mounting flanges can extend 
out near

the edges of the back mounting plate.


Is there any reason I can't clamp the motor in a vice and pop in two 
holes

and tap them with a bottom tap at the spacing of the mounting flange?

John

You've got 4 theaded bolt holes there. Jon. 3mmx.5 threaded IIRC. And 
the heat is not going to be hotter than PETG plastic from a 3d printer 
to survive long term.  So I would layout a thin plastic to bolt to those 
4 holes, and would have standoffs to hold the encoder body in the 
correct position. sticking up with un-threaded holes about 3.2mm in 
diameter and 3mm deep all the way thru the standoff. The printer will 
shrink the holes by .4mm making a std 3mm metric screw be self 
threading. You could do all that in 3mm which should still let the disk 
for the encoder be mounted correctly. You could also machine it out of 
1/8 alu panel. But the plastic would be additional insurance against a 
ground loop electronically. I could cobble that up in OpenSCAD and have 
the printer working on it in an hour.


If not fam with OpenSCAD, get familiar with it, its the best designer of 
3d printed parts out there.  I just got a new printer calibrated a few 
hours ago, and am about to make a mount for a new, different controller 
card for another of my printers. From scratch to gluing it into the 
bottom of a 2 trees sp-5 to replace the OEM controller which has blown 
for the second time.  Will be done and glue setting by around 7AM.


That may have been a little optimistic, I started with OpenSCAD about 
3AMm printer warmng up at 4:15, Cura, the slicer says 3+ hours to 
finished.   Halfway thru 1st layer of 24 at 4:33. Everything of a new 
install except the gcode visualizer working normally on a brand new 
Creality Ender5 S1, this is its first print. Printer re-flashed with 
klipper, moonraker and mainsail are supplying the controls thru a web 
server interface, I can watch it in person, or log into the bananapi m5 
running it and see the same thing.  Whats not to like? Lights out 
manufacturing, I'm going back to bed.


Addendum, woke up about 7:15, printer done and cooled off. Print stuck a 
little too good, and too thin to flex the bed sheet to remove so had to 
use a sharp putty knife.  Test fit, oops, my 8mm SHCS screws are too 
long yet, add 3mm to height of bosses, start remake but running printer 
faster to reduce adhesion. I need 2 maybe 3, all 3 s/b done by 3pm. Then 
I need a glue in place edge mount for a 60x15mm fan, same story but I 
can make them 3 up on this printers 220mm square bed. 3d printers are 
handier for us than sliced bread AND bottled beer.  The modifications to 
my remotored & rebuilt for linuxcnc 6040 gantry mill for a 4th axis are 
printed. To me, they are a welcome enhancement to my creative ability.



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Cheers, Gene Heskett.


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, 1940)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 



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Re: [Emc-users] Drilling holes in the back of a stepper motor

[andy pugh]

On Sun, 25 Jun 2023 at 10:36, John Dammeyer  wrote:

> The plate can't be thick enough to hold both the encoder and threads for 
> screws and still have the encoder disk mount to the back shaft.

I would use countersunk screws from the motor side, with nuts to hold
the encoder to the plate, then bolt the plate to the motor.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[marcus . bowman]

On 2023-06-25 10:33, andrew beck wrote:

Adapter plate sounds easiest to me



+1 for an adapter plate; its much safer and also more versatile.
Have you thought of mounting the encoder parallel to the stepper, and 
using a small pulley and belt between the shafts. That might give you 
more mounting options.


Another option would be if the motor have long bolts running through 
from front to back, those could be extended to hold an adapter plate.


Or could the encoder be driven off the front of the motor, using the 
existing belt (if your setup uses one).


Marcus






On Sun, 25 Jun 2023, 21:01 andy pugh,  wrote:


On Sun, 25 Jun 2023 at 04:31, John Dammeyer 
wrote:

> Is there any reason I can't clamp the motor in a vice and pop in two
holes
> and tap them with a bottom tap at the spacing of the mounting flange?

I have done it in-situ, but there really isn't all that much metal in
there.

I think pulling the back cover off (leaving the rotor in place) and
choosing your mounting point carefully would probably be best.

Or, as Gene says, use the existing holes, very short screws, and an
adaptor plate.

--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[andrew beck]

Adapter plate sounds easiest to me

On Sun, 25 Jun 2023, 21:01 andy pugh,  wrote:

> On Sun, 25 Jun 2023 at 04:31, John Dammeyer 
> wrote:
>
> > Is there any reason I can't clamp the motor in a vice and pop in two
> holes
> > and tap them with a bottom tap at the spacing of the mounting flange?
>
> I have done it in-situ, but there really isn't all that much metal in
> there.
>
> I think pulling the back cover off (leaving the rotor in place) and
> choosing your mounting point carefully would probably be best.
>
> Or, as Gene says, use the existing holes, very short screws, and an
> adaptor plate.
>
> --
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is
> designed for the especial use of mechanical geniuses, daredevils and
> lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1912
>
>
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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

The problem is the rear shaft isn't that long.  

I went through the process of considering an adaptor plate that fastened to the 
4 holes.There may be a fancy way of making a thick plate with a thinned 
area just for the encoder mount.  But it would have to have a stud protruding 
away from the back and then a nut.  The plate can't be thick enough to hold 
both the encoder and threads for screws and still have the encoder disk mount 
to the back shaft.

The alternative would be to press fit on a shaft extension and then use the 
stepper motor to turn the extension to be symmetrical with the axis of the 
motor shaft.   Then I could use a thicker mounting plate.

Or, given that the motor drives a 25:1 planetary gear and I'm really only 
interested in tracking motor revolutions and detecting stall conditions (hence 
quadrature) I could likely get away with a custom disk and some slotted sensors 
too.  Also more complicated to build.  

Trying to keep it simple and the easiest is to have the encoder screw directly 
to the back of the motor.  However with StepperOnline motor by the time it's 
here in Cdn $ it's over $100.  So I can take the risk and drill holes in the 
back.  Or get creative with other approaches.
John


-Original Message-
From: andy pugh [mailto:bodge...@gmail.com] 
Sent: June 25, 2023 1:57 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor

On Sun, 25 Jun 2023 at 04:31, John Dammeyer  wrote:

> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?

I have done it in-situ, but there really isn't all that much metal in there.

I think pulling the back cover off (leaving the rotor in place) and
choosing your mounting point carefully would probably be best.

Or, as Gene says, use the existing holes, very short screws, and an
adaptor plate.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
� George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[andy pugh]

On Sun, 25 Jun 2023 at 04:31, John Dammeyer  wrote:

> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?

I have done it in-situ, but there really isn't all that much metal in there.

I think pulling the back cover off (leaving the rotor in place) and
choosing your mounting point carefully would probably be best.

Or, as Gene says, use the existing holes, very short screws, and an
adaptor plate.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] Drilling holes in the back of a stepper motor

[gene heskett]

On 6/24/23 23:29, John Dammeyer wrote:

I want to add an encoder onto the back of this stepper motor.  I can install
either a US Digital or a CUI since both mounting flanges can extend out near
the edges of the back mounting plate.

  


Is there any reason I can't clamp the motor in a vice and pop in two holes
and tap them with a bottom tap at the spacing of the mounting flange?

John

You've got 4 theaded bolt holes there. Jon. 3mmx.5 threaded IIRC. And 
the heat is not going to be hotter than PETG plastic from a 3d printer 
to survive long term.  So I would layout a thin plastic to bolt to those 
4 holes, and would have standoffs to hold the encoder body in the 
correct position. sticking up with un-threaded holes about 3.2mm in 
diameter and 3mm deep all the way thru the standoff. The printer will 
shrink the holes by .4mm making a std 3mm metric screw be self 
threading. You could do all that in 3mm which should still let the disk 
for the encoder be mounted correctly. You could also machine it out of 
1/8 alu panel. But the plastic would be additional insurance against a 
ground loop electronically. I could cobble that up in OpenSCAD and have 
the printer working on it in an hour.


If not fam with OpenSCAD, get familiar with it, its the best designer of 
3d printed parts out there.  I just got a new printer calibrated a few 
hours ago, and am about to make a mount for a new, different controller 
card for another of my printers. From scratch to gluing it into the 
bottom of a 2 trees sp-5 to replace the OEM controller which has blown 
for the second time.  Will be done and glue setting by around 7AM.


That may have been a little optimistic, I started with OpenSCAD about 
3AMm printer warmng up at 4:15, Cura, the slicer says 3+ hours to 
finished.   Halfway thru 1st layer of 24 at 4:33. Everything of a new 
install except the gcode visualizer working normally on a brand new 
Creality Ender5 S1, this is its first print. Printer re-flashed with 
klipper, moonraker and mainsail are supplying the controls thru a web 
server interface, I can watch it in person, or log into the bananapi m5 
running it and see the same thing.  Whats not to like? Lights out 
manufacturing, I'm going back to bed.






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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, 1940)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 



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Re: [Emc-users] Drilling holes in the back of a stepper motor

[John Dammeyer]

Some of the stepper motors available from SteppersOnline show two pairs of
screw holes near the edges.  And you are correct.  Youtube videos of stepper
dismantling show that it's pretty thin near the edges and the windings are
really close.
However, I've read that once you dismantle a stepper motor it loses some of
the magnetism.   That they are magnetised with much higher pulses of current
when the motor is assembled.  But that might also be an urban legend.
Anyway, the back end also has the motor leads coming out so pulling it apart
may also damage it.  Or not.  Easier to just order a new motor perhaps.
John


-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com] 
Sent: June 24, 2023 10:59 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Drilling holes in the back of a stepper motor


> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?

The metal end plate might be a lot thinner than it appears from the outside.
Is it thick enough to support threading?  It might be a thin diarist part.
Maybe look inside first?

But on the other hand, the load on the mounting screws would be nearly
nothing.   

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Re: [Emc-users] Drilling holes in the back of a stepper motor

[Chris Albertson]

> Is there any reason I can't clamp the motor in a vice and pop in two holes
> and tap them with a bottom tap at the spacing of the mounting flange?

The metal end plate might be a lot thinner than it appears from the outside.  
Is it thick enough to support threading?  It might be a thin diarist part.  
Maybe look inside first?

But on the other hand, the load on the mounting screws would be nearly nothing. 
  

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