Re: [Emc-users] G33.1 error then g-code file parsed

[John Dammeyer]

OK.
I'll try that for you.  
I'm wondering if perhaps spindle acceleration time or some other HAL
parameter gets flagged with an incorrect error message.   I've done power
tapping from .ngc files without issue but I've not used the 'I' parameter.
John

-Original Message-
From: Nicklas SB Karlsson [mailto:n...@nksb.eu] 
Sent: June 25, 2023 10:09 PM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] G33.1 error then g-code file parsed

Run from MDI then there is no error message for me either. Put the same 
rows in a .ngc file adding M2 and bottom there is an interpreter error 
message then loading the file and display not updated. Looking at bottom 
the program is however actually loaded and seems to work OK.


Nicklas Karlsson


Den 2023-06-26 kl. 01:26, skrev John Dammeyer:
> I ran the following commands from the MDI without issue from AXIS 2.8.1
with
> MESA 7i92H controlling an AC Servo motor (step/dir) for the spindle.
> G1 X0 Y0 F20
> G1 Z0
> S200 M3
> G33.1 Z-0.7 K0.05 I3.0
> M5
>
> Interesting watching the spindle RPM indicator, and you can hear it too of
> course.
> Goes down to tap the 0.05" pitch (20TPI thread) at 200RPM
> Reverses and goes up at 600 RPM.
> Without the I3.0 it goes up at 200 RPM.
>
> John
>
>
> -Original Message-
> From: Nicklas SB Karlsson [mailto:n...@nksb.eu]
> Sent: June 25, 2023 9:07 AM
> To: emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] G33.1 error then g-code file parsed
>
> There is positioning move XYZ in real program but happened to remove
> them then I should make a small test case.
>
> Adding positioning move to test case make no difference. Linuxcnc report
> a file interpretation error and do not update display but program seems
> to work supposed to.
>
> Nicklas Karlsson
>
>
> Den 2023-06-23 kl. 16:20, skrev Chris Radek:
>> I would add positioning moves (positioning all of XYZ) before the
>> G33.1 because otherwise the tapped hole can be anywhere - the
>> program is indeterminate.  This sure might mess up any attempt by
>> your GUI to check the program or generate a preview.
>>
>> Chris
>>
>> On Wed, Jun 14, 2023 at 09:14:20PM +0200, Nicklas SB Karlsson wrote:
>>> I put the lines below into a file:
>>>
>>>?? M3 S100
>>>?? G33.1 Z-30.474 K0.8 I3.000
>>>?? M5
>>>?? M2
>>>
>>> Then I read into Linuxcnc I get error message:
>>>
>>>?? parse_file interp_error
>>>
>>> Removing the line with G33.1 then no error message so it is something
>>> with this row. Program do however execute as expected with G33.1 line
>>> even though there is an error message so no real problem. Also execute
>>> without an error message if run manually in MDI mode. Use origin/master
>>> last commit Mon May 8 16:10:03 2023 +0200
>>> 404aa407f136ce91a3e6bf911c7bda54011a74e9 Anybody else had similar
> problem?
>>>
>>> Nicklas Karlsson
>>>
>>>
>>>
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>>> Emc-users@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/emc-users
>>>
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Re: [Emc-users] G33.1 error then g-code file parsed

[Nicklas SB Karlsson]

Run from MDI then there is no error message for me either. Put the same 
rows in a .ngc file adding M2 and bottom there is an interpreter error 
message then loading the file and display not updated. Looking at bottom 
the program is however actually loaded and seems to work OK.



Nicklas Karlsson


Den 2023-06-26 kl. 01:26, skrev John Dammeyer:

I ran the following commands from the MDI without issue from AXIS 2.8.1 with
MESA 7i92H controlling an AC Servo motor (step/dir) for the spindle.
G1 X0 Y0 F20
G1 Z0
S200 M3
G33.1 Z-0.7 K0.05 I3.0
M5

Interesting watching the spindle RPM indicator, and you can hear it too of
course.
Goes down to tap the 0.05" pitch (20TPI thread) at 200RPM
Reverses and goes up at 600 RPM.
Without the I3.0 it goes up at 200 RPM.

John


-Original Message-
From: Nicklas SB Karlsson [mailto:n...@nksb.eu]
Sent: June 25, 2023 9:07 AM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] G33.1 error then g-code file parsed

There is positioning move XYZ in real program but happened to remove
them then I should make a small test case.

Adding positioning move to test case make no difference. Linuxcnc report
a file interpretation error and do not update display but program seems
to work supposed to.

Nicklas Karlsson


Den 2023-06-23 kl. 16:20, skrev Chris Radek:

I would add positioning moves (positioning all of XYZ) before the
G33.1 because otherwise the tapped hole can be anywhere - the
program is indeterminate.  This sure might mess up any attempt by
your GUI to check the program or generate a preview.

Chris

On Wed, Jun 14, 2023 at 09:14:20PM +0200, Nicklas SB Karlsson wrote:

I put the lines below into a file:

   ?? M3 S100
   ?? G33.1 Z-30.474 K0.8 I3.000
   ?? M5
   ?? M2

Then I read into Linuxcnc I get error message:

   ?? parse_file interp_error

Removing the line with G33.1 then no error message so it is something
with this row. Program do however execute as expected with G33.1 line
even though there is an error message so no real problem. Also execute
without an error message if run manually in MDI mode. Use origin/master
last commit Mon May 8 16:10:03 2023 +0200
404aa407f136ce91a3e6bf911c7bda54011a74e9 Anybody else had similar

problem?


Nicklas Karlsson



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Re: [Emc-users] G33.1 error then g-code file parsed

[John Dammeyer]

I ran the following commands from the MDI without issue from AXIS 2.8.1 with
MESA 7i92H controlling an AC Servo motor (step/dir) for the spindle.
G1 X0 Y0 F20
G1 Z0
S200 M3
G33.1 Z-0.7 K0.05 I3.0
M5

Interesting watching the spindle RPM indicator, and you can hear it too of
course.
Goes down to tap the 0.05" pitch (20TPI thread) at 200RPM
Reverses and goes up at 600 RPM.
Without the I3.0 it goes up at 200 RPM.

John


-Original Message-
From: Nicklas SB Karlsson [mailto:n...@nksb.eu] 
Sent: June 25, 2023 9:07 AM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] G33.1 error then g-code file parsed

There is positioning move XYZ in real program but happened to remove 
them then I should make a small test case.

Adding positioning move to test case make no difference. Linuxcnc report 
a file interpretation error and do not update display but program seems 
to work supposed to.

Nicklas Karlsson


Den 2023-06-23 kl. 16:20, skrev Chris Radek:
> I would add positioning moves (positioning all of XYZ) before the
> G33.1 because otherwise the tapped hole can be anywhere - the
> program is indeterminate.  This sure might mess up any attempt by
> your GUI to check the program or generate a preview.
>
> Chris
>
> On Wed, Jun 14, 2023 at 09:14:20PM +0200, Nicklas SB Karlsson wrote:
>> I put the lines below into a file:
>>
>>   ?? M3 S100
>>   ?? G33.1 Z-30.474 K0.8 I3.000
>>   ?? M5
>>   ?? M2
>>
>> Then I read into Linuxcnc I get error message:
>>
>>   ?? parse_file interp_error
>>
>> Removing the line with G33.1 then no error message so it is something
>> with this row. Program do however execute as expected with G33.1 line
>> even though there is an error message so no real problem. Also execute
>> without an error message if run manually in MDI mode. Use origin/master
>> last commit Mon May 8 16:10:03 2023 +0200
>> 404aa407f136ce91a3e6bf911c7bda54011a74e9 Anybody else had similar
problem?
>>
>>
>> Nicklas Karlsson
>>
>>
>>
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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
>> 
>> 
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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] G33.1 error then g-code file parsed

[Nicklas SB Karlsson]

There is positioning move XYZ in real program but happened to remove 
them then I should make a small test case.


Adding positioning move to test case make no difference. Linuxcnc report 
a file interpretation error and do not update display but program seems 
to work supposed to.


Nicklas Karlsson


Den 2023-06-23 kl. 16:20, skrev Chris Radek:

I would add positioning moves (positioning all of XYZ) before the
G33.1 because otherwise the tapped hole can be anywhere - the
program is indeterminate.  This sure might mess up any attempt by
your GUI to check the program or generate a preview.

Chris

On Wed, Jun 14, 2023 at 09:14:20PM +0200, Nicklas SB Karlsson wrote:

I put the lines below into a file:

  ?? M3 S100
  ?? G33.1 Z-30.474 K0.8 I3.000
  ?? M5
  ?? M2

Then I read into Linuxcnc I get error message:

  ?? parse_file interp_error

Removing the line with G33.1 then no error message so it is something
with this row. Program do however execute as expected with G33.1 line
even though there is an error message so no real problem. Also execute
without an error message if run manually in MDI mode. Use origin/master
last commit Mon May 8 16:10:03 2023 +0200
404aa407f136ce91a3e6bf911c7bda54011a74e9 Anybody else had similar problem?


Nicklas Karlsson



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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.
--
"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.
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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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