Re: [Emc-users] Serial Port access

[John Dammeyer]

> From: Gene Heskett [mailto:ghesk...@shentel.net]
> On Monday 13 September 2021 18:11:44 John Dammeyer wrote:
> 
> > Hi Gene,
> > I was able to use your pyvcp information along with the web documents
> > to get my own slider working. In the CAN message screen grab you can
> > see id=218, dlc=4, and the first two bytes representing 0x0032 in
> > Little Endian format.  That value in decimal is 50. Scale screen grab
> > shows the slider set at 50.  Drag the slider back and forth and the
> > CAN message changes. And on the scope the screen shot shows 5V.  Drag
> > the slider back and forth and the voltage trace changes amplitude.
> > That voltage is based on the received CANopen message sent from the
> > slider on the Pi4 LCNC. Thanks again for your help.
> > John Dammeyer
> >
> NP John, glad I could help.

I realized after I posted all that and looked at the PIC source code that I 
remembered incorrectly (ie. Forgot)  that the PWM values are 8 bits not 16 with 
a resolution of 1%.  Only two bytes are needed in the message.  The code below 
shows how it's properly converted and set into the hardware PWM generation 
registers.

  case 0x200 :  // Receive PDO 1
// PWM Outputs for LH CONN pin 2,11
if (id == NodeID ) {
OC3RS = ScalePWM((int)CANOpenMsg.d.data[0]);
OC4RS = ScalePWM((int)CANOpenMsg.d.data[1]);
ObjectDictionaryValues[XIM_PWM1_NDX] = ReportPWM(0);
ObjectDictionaryValues[XIM_PWM2_NDX] = ReportPWM(1);
}
break;


> 
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
> 
> 
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Re: [Emc-users] Spindle setup for 5i25/7i76

[Gene Heskett]

On Monday 13 September 2021 18:20:17 Alan Condit wrote:

> Update, I found some old photos of the motor’s id plate. I thought it
> was rated at 6000 rpm at 110 volts, but it was really only 3000rpm at
> 110volts. When I adjusted the maximum rpm in PNCConf, suddenly I was
> getting a solid “At Speed” indicator.
>
> John,
>I will still try measuring the analog voltage at various rpms and
> if I can get at it I will measure the DC voltage out.
>
> Peter,
> Thanks for the suggestion about the encoder phasing, I don’t think
> it was going to work without fixing that.
>
> Gene,
>  Could you go ahead and send me your configs. I can have a
> jackshaft driven by toothed belt with a 3 step pulley or a pair of
> three step pulleys on the motor and spindle. So six possible gearing
> combinations.
>
I'll tarball that whole config directory and send it by PM.

But, even with 6 speeds, you are belt driven so there will be an unk 
amount of belt slippage.  So if turning a spindle, the random slippage 
will probably trash any holes you try to to rigid tap. The bare minimum 
still needs a once per rev index pulse from the spindle.


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


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Re: [Emc-users] Suggestions for a retrofit.

[John Dammeyer]

Hi John,
Yes, I use step/dir for a harmonic drive AC Servo that as yet still has to be 
put into a casting and married to a face plate.   For now it sits on the cart 
beside the mill and I can make the A axis turn.
http://www.autoartisans.com/mill/HarmonicDrive/D8X_5784_Plastic_Mount.jpg
I did try to get one of my DC Servos also working with a second STMBL.  However 
I had trouble tuning it and the HP_UHU (105VDC power supply) has been more than 
adequate so for now I'm staying with that.

I used step/dir because initially my PC is dual boot and I wanted both MACH3 
and LCNC to work.  Along with also a BeagleBone with a cape for MachineKit so 
Parallel port and BoB were mandatory.  That excludes any of the smart serial 
unless it terminated in a standard Parallel port configuration.

John Dammeyer

> -Original Message-
> From: John Figie [mailto:zephyr9...@gmail.com]
> Sent: September-13-21 3:39 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Suggestions for a retrofit.
> 
> John,
> 
> Thanks for the info so it looks like the Mesa Smart Serial interface can be
> used with this drive. If I understand correctly the SSERIAL interface comes
> from one of the mesa FPGA I/O cards and connects to the STMBL drive. (I
> mean that is one way to interface to the STMBL drive). Otherwise a step and
> direction or a quadrature input would be used with the STMBL drive.
> 
> On Mon, Sep 13, 2021 at 3:53 PM John Dammeyer 
> wrote:
> 
> > John,
> > The work has already been done with the STMBL project.  The biggest issue
> > with that one was the 3 phase motor driver was discontinued so that caused
> > a bit of panic.  But it's an open source project that can use step/dir or
> > smart serial from the MESA boards.
> >
> > https://github.com/rene-dev/stmbl
> >
> > John Dammeyer
> >
> > > -Original Message-
> > > From: John Figie [mailto:zephyr9...@gmail.com]
> > > Sent: September-13-21 1:32 PM
> > > To: Enhanced Machine Controller (EMC)
> > > Subject: Re: [Emc-users] Suggestions for a retrofit.
> > >
> > > It's been a long time and I have not made much progress. Except now I am
> > > retired from my job as an electrical engineer. In my job I developed
> > > industrial PMAC servo drives for a leading industrial controls
> > manufacturer
> > > located in Milwaukee. So to solve my servo amplifier problem I have
> > decided
> > > to build my own and have already made significant progress. My homemade
> > > drives will be able to run either DC brush motors or in the future AC
> > > motors. I have a basic torque mode drive in the process of development
> > but
> > > I am thinking I would like the drive to be a velocity mode drive.
> > >
> > > My question now is how to interface to LinuxCNC? I really want to connect
> > > all of my I/O using the mesa ethernet cards like the 7I80. From the 7I80
> > it
> > > looks like there is a way to have SPI interfaces. It seems like the SPI
> > > would be one way to make a simple digital interface to my drives. The
> > 7I80
> > > would send velocity commands and velocity feedback to the drives. The
> > > drives would return status and fault information back to LinuxCNC.
> > >
> > > Is it possible for me to use the SPI interfaces with LinuxCNC in the way
> > I
> > > have described? If so, how does one go about setting up the SPI
> > interfaces
> > > and defining what data is passed back and forth? I am hoping Andy Pugh,
> > PCW
> > > or someone that knows can comment.
> > >
> > > LinuxCNC  <--Ethernet--> 7I80 -<> I/O inputs and outputs
> > >  |-<> SPI comms to
> > > servo amps  7I46?
> > >  | < encoder inputs
> > for
> > > axis and MPGs
> > >
> > > LinuxCNC with position loop only should be able to run with a slower
> > 1mSec
> > > or maybe 500uSec thread and no other high speed thread would be needed. I
> > > may however need to get the velocity feedback to my servo drive at a
> > faster
> > > rate for best/better performance.
> > >
> > > My reason for wanting Ethernet is I do not have to have my LinuxCNC PC on
> > > or embedded in my machine, it can be several meters away mounted where it
> > > won't be subject to heat and vibration. In addition with only one
> > > interface, a PC upgrade or repair / swap is easy.
> > >
> > >
> > > Regards,
> > >
> > > John Figie
> > >
> > >
> > > On Sun, Nov 29, 2020 at 6:47 PM dave engvall 
> > wrote:
> > >
> > > >
> > > >
> > > > On 11/27/20 10:52 AM, andy pugh wrote:
> > > > > On Fri, 27 Nov 2020 at 18:45, John Figie 
> > wrote:
> > > > >
> > > > >> I think I am going to attempt to figure out what the parameters of
> > my
> > > > motor
> > > > >> are and make a model to simulate my control loop. For hobby stuff I
> > > > think
> > > > >> LTspice may be good to model and simulate.
> > > > > I am not sure what you hope to gain from a model. The data to
> > populate
> > > > > it would have to come from the actual 

Re: [Emc-users] Serial Port access

[Gene Heskett]

On Monday 13 September 2021 18:11:44 John Dammeyer wrote:

> Hi Gene,
> I was able to use your pyvcp information along with the web documents
> to get my own slider working. In the CAN message screen grab you can
> see id=218, dlc=4, and the first two bytes representing 0x0032 in
> Little Endian format.  That value in decimal is 50. Scale screen grab
> shows the slider set at 50.  Drag the slider back and forth and the
> CAN message changes. And on the scope the screen shot shows 5V.  Drag
> the slider back and forth and the voltage trace changes amplitude. 
> That voltage is based on the received CANopen message sent from the
> slider on the Pi4 LCNC. Thanks again for your help.
> John Dammeyer
>
NP John, glad I could help.

Take care now.

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


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Re: [Emc-users] Suggestions for a retrofit.

[John Figie]

John,

Thanks for the info so it looks like the Mesa Smart Serial interface can be
used with this drive. If I understand correctly the SSERIAL interface comes
from one of the mesa FPGA I/O cards and connects to the STMBL drive. (I
mean that is one way to interface to the STMBL drive). Otherwise a step and
direction or a quadrature input would be used with the STMBL drive.

On Mon, Sep 13, 2021 at 3:53 PM John Dammeyer 
wrote:

> John,
> The work has already been done with the STMBL project.  The biggest issue
> with that one was the 3 phase motor driver was discontinued so that caused
> a bit of panic.  But it's an open source project that can use step/dir or
> smart serial from the MESA boards.
>
> https://github.com/rene-dev/stmbl
>
> John Dammeyer
>
> > -Original Message-
> > From: John Figie [mailto:zephyr9...@gmail.com]
> > Sent: September-13-21 1:32 PM
> > To: Enhanced Machine Controller (EMC)
> > Subject: Re: [Emc-users] Suggestions for a retrofit.
> >
> > It's been a long time and I have not made much progress. Except now I am
> > retired from my job as an electrical engineer. In my job I developed
> > industrial PMAC servo drives for a leading industrial controls
> manufacturer
> > located in Milwaukee. So to solve my servo amplifier problem I have
> decided
> > to build my own and have already made significant progress. My homemade
> > drives will be able to run either DC brush motors or in the future AC
> > motors. I have a basic torque mode drive in the process of development
> but
> > I am thinking I would like the drive to be a velocity mode drive.
> >
> > My question now is how to interface to LinuxCNC? I really want to connect
> > all of my I/O using the mesa ethernet cards like the 7I80. From the 7I80
> it
> > looks like there is a way to have SPI interfaces. It seems like the SPI
> > would be one way to make a simple digital interface to my drives. The
> 7I80
> > would send velocity commands and velocity feedback to the drives. The
> > drives would return status and fault information back to LinuxCNC.
> >
> > Is it possible for me to use the SPI interfaces with LinuxCNC in the way
> I
> > have described? If so, how does one go about setting up the SPI
> interfaces
> > and defining what data is passed back and forth? I am hoping Andy Pugh,
> PCW
> > or someone that knows can comment.
> >
> > LinuxCNC  <--Ethernet--> 7I80 -<> I/O inputs and outputs
> >  |-<> SPI comms to
> > servo amps  7I46?
> >  | < encoder inputs
> for
> > axis and MPGs
> >
> > LinuxCNC with position loop only should be able to run with a slower
> 1mSec
> > or maybe 500uSec thread and no other high speed thread would be needed. I
> > may however need to get the velocity feedback to my servo drive at a
> faster
> > rate for best/better performance.
> >
> > My reason for wanting Ethernet is I do not have to have my LinuxCNC PC on
> > or embedded in my machine, it can be several meters away mounted where it
> > won't be subject to heat and vibration. In addition with only one
> > interface, a PC upgrade or repair / swap is easy.
> >
> >
> > Regards,
> >
> > John Figie
> >
> >
> > On Sun, Nov 29, 2020 at 6:47 PM dave engvall 
> wrote:
> >
> > >
> > >
> > > On 11/27/20 10:52 AM, andy pugh wrote:
> > > > On Fri, 27 Nov 2020 at 18:45, John Figie 
> wrote:
> > > >
> > > >> I think I am going to attempt to figure out what the parameters of
> my
> > > motor
> > > >> are and make a model to simulate my control loop. For hobby stuff I
> > > think
> > > >> LTspice may be good to model and simulate.
> > > > I am not sure what you hope to gain from a model. The data to
> populate
> > > > it would have to come from the actual machine, and at that point you
> > > > might as well just get on with it.
> > > >
> > > IIRC early versions of emc had motor parameters, etc tacked on the the
> > > end of the parameters for each axis. I don't know if any use was ever
> > > made of that.
> > > Maybe some of the early emc-ers with their memory still intact will
> > > remember as well as a model to insert the data into.
> > > Dave
> > >
> > > Just a comment: I've never had much success using torque mode: that
> > > doesn't mean I should not go back and revisit it.
> > >
> > >
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> > >
> >
> > ___
> > Emc-users mailing list
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
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Re: [Emc-users] Spindle setup for 5i25/7i76

[Alan Condit]

Update, I found some old photos of the motor’s id plate. I thought it was rated 
at 6000 rpm at 110 volts, but it was really only 3000rpm at 110volts. When I 
adjusted the maximum rpm in PNCConf, suddenly I was getting a solid “At Speed” 
indicator. 

John,
   I will still try measuring the analog voltage at various rpms and if I can 
get at it I will measure the DC voltage out.

Peter,
Thanks for the suggestion about the encoder phasing, I don’t think it was 
going to work without fixing that.

Gene,
 Could you go ahead and send me your configs. I can have a jackshaft driven 
by toothed belt with a 3 step pulley or a pair of three step pulleys on the 
motor and spindle. So six possible gearing combinations.


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Re: [Emc-users] Serial Port access

[John Dammeyer]

Hi Gene,
I was able to use your pyvcp information along with the web documents to get my 
own slider working.
In the CAN message screen grab you can see id=218, dlc=4, and the first two 
bytes representing 0x0032 in Little Endian format.  That value in decimal is 50.
Scale screen grab shows the slider set at 50.  Drag the slider back and forth 
and the CAN message changes.
And on the scope the screen shot shows 5V.  Drag the slider back and forth and 
the voltage trace changes amplitude.  That voltage is based on the received 
CANopen message sent from the slider on the Pi4 LCNC.
Thanks again for your help.
John Dammeyer

> -Original Message-
> From: Gene Heskett [mailto:ghesk...@shentel.net]
> Piece of cake John, the pyvcp .xml file snippet that draws them:
> but there's a wagon load of stuff above it too. :o)

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Re: [Emc-users] Spindle setup for 5i25/7i76

[Gene Heskett]

On Monday 13 September 2021 16:51:42 Alan Condit wrote:

> John, Peter and Gene,
>
> I have the Cycletrol-150 Manual. It says that you can replace the 5k
> ohm potentiometer with a 0-10v analog signal. The 7i76 manual says
> that you can use it to replace a 5k potentiometer control (0-10v). So
> that should work and indeed seems to be working. I have tried
> adjusting the detectors to 90°. I have an old Tectronix scope and they
> look pretty good there. It now has a solid “at speed indication” up to
> about 250rpm. So now I am suspecting that I don’t have the PNCConf
> configuration quite correct for the spindle. At the top of the range
> the Speed Indicator fluctuates from about 400 to 600 rpm while the
> motor sounds like it is holding dead steady. One of my problems is
> that I don’t actually know what the rpm of the motor should be at
> 90volts. It is a Pacific Scientific motor rated 1.5hp at 110v DC.
>
> Thanks,
> Alan

If you are falling apart at 250 rpms, the first thing I would check is 
the speed of any opto stuff in the path from your encoder output back to 
LinuxCNC to the the encoder that shuld be labeled a decoder in the 
hardware at the computer end of the path. Get that old tech to look at 
the encoder inputs at the 5i25 or 7i76. I'd be willing to bet a small 
sum the good, square waves from your hardware are half amplitude saw 
teeth by the time they get to the mesa card(s)
>
> > I built a new controller for my 9x20 lathe using a 5i25/7i76 combo.
> > I thought I had everything working but I still can’t get the spindle
> > working correctly. I have a 1.5hp PMDC treadmill motor that I am
> > controlling with a Cycletrol-150 DC controller. The am using the
> > analog out from the 7i76 to replace the potentiometer to control the
> > spindle speed. I have a 100 slot encoder with index (homemade) on
> > the spindle.

That would be 400 edges per turn. And since the motor doesn't seem to be 
affected, the feedback to the spindle's pid is also getting lost.
> >
> > The spindle starts under LCNC control but I am not getting an “at
> > speed indication” at above about 100rpm. The motor sounds like is is
> > running at a steady speed but the Spindle Speed indicator fluctuates
> > wildly. I am suspicious of the spindle encoder. Before I was just
> > running it as a 100 count counter with index and it worked fine. I
> > can’t figure out in PNCConf how to set up a spindle counter with
> > index for the 7i76.
> >
> >> From: "John Dammeyer" 
> >>
> >> Hi Alan,
> >>
> >> This is what I found for a Cycletrol DC motor controller.
> >> http://www.grahammotorandcontrols.com/item_dc_motor_controller/176B
> >>6002/58
> >>
> >>
> >> There is no guarantee that a PWM output will emulate a
> >> potentiometer.  That's the first place to look First put the pot
> >> back and measure the voltage between the wiper and ground as you
> >> control the speed from 0 to full RPM open loop.  And depending on
> >> how it's powered be careful that the pot inputs aren't indirectly
> >> connected to ground.
> >>
> >> It's always possible the speed control won't work unless there is
> >> also 5K Ohm between pin 9 and 11.
> >>
> >> It's also possible the pot changes the resistance (as a rheostat)
> >> in a feedback circuit so input PWM may or may not work.
> >>
> >> Also PWM is exactly that pulse width.  Unless you have a filter
> >> capacitor across that with a bleeder resistor to ground (Pin 11)
> >> the internal circuit many not integrate the PWM enough for it to
> >> work.
> >>
> >> For example I bought a small Chinese PWM to 0-10V module that has
> >> the rule that the PWM frequency can't be higher than 1kHz.  Try it
> >> with 10kHz and it won't create a lower voltage.  So PWM frequency
> >> is a parameter that must be correct.
> >>
> >> I also, way back, bought a step/dir to 0-10V controller that
> >> produced 10V at 25kHz step rate.  The problem was my ELS was
> >> limited to 20kHz so I never could get 10V out of it.
> >>
> >> I don't believe your 100 PPR encoder is the issue.  I'm running my
> >> spindle with 60 PPR and can do power tapping on the mill.
> >>
> >> It may still be possible to find these UHU or HP_UHU kits
> >> somewhere.  I ended up using them because the GECKO servo drives I
> >> bought were only good to 80V and my servo motors like more than
> >> 90V.  The HP_UHU kit was good to over 200VDC.
> >> https://www.cnczone.com/forums/servo-motors-drives/342836-uhu-servo
> >>-controller-build.html
> >>
> >>
> >> Similarly there are still some STMBL kits out there.  These can
> >> actually take the smart serial input from the MESA boards or
> >> step/dir.  I'm not sure that 0-10V was very implemented.
> >> https://www.pcbway.com/project/shareproject/stmbl_servo_motor_drive
> >>.html
> >>
> >> John
> >>
> >>
> >>
> >> From: "Peter C. Wallace" 
> >>
> >> I would first check the A/B phasing and symmetry by monitoring the
> >> A and B inputs with halscope when turning at a slow speed (say 100
> >> RPM or less) The pins to 

Re: [Emc-users] Spindle setup for 5i25/7i76

[John Dammeyer]

Alan,
Can you run the motor open loop with a 0V-10V power supply?If you remove 
the CNC from the loop first then you can measure top speed with 90V and 10V 
input.

Next, put the CNC system back on it and use the scope to look at the PWM 
output.   If it's not a voltage level but still pulses add a 10uF 16V capacitor 
across it.  Then see if the voltage level changes from 0V to 10V.

Baby steps...
John



> -Original Message-
> From: Alan Condit [mailto:condit.a...@gmail.com]
> Sent: September-13-21 1:52 PM
> To: Emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] Spindle setup for 5i25/7i76
> 
> John, Peter and Gene,
> 
> I have the Cycletrol-150 Manual. It says that you can replace the 5k ohm 
> potentiometer with a 0-10v analog signal. The 7i76 manual
> says that you can use it to replace a 5k potentiometer control (0-10v). So 
> that should work and indeed seems to be working. I have
> tried adjusting the detectors to 90�. I have an old Tectronix scope and they 
> look pretty good there. It now has a solid �at speed
> indication� up to about 250rpm. So now I am suspecting that I don�t have the 
> PNCConf configuration quite correct for the spindle.
> At the top of the range the Speed Indicator fluctuates from about 400 to 600 
> rpm while the motor sounds like it is holding dead
> steady.
> One of my problems is that I don�t actually know what the rpm of the motor 
> should be at 90volts. It is a Pacific Scientific motor rated
> 1.5hp at 110v DC.
> 
> Thanks,
> Alan
> 
> 
> 
> > I built a new controller for my 9x20 lathe using a 5i25/7i76 combo. I 
> > thought I had everything working but I still can�t get the
> spindle working correctly.
> > I have a 1.5hp PMDC treadmill motor that I am controlling with a 
> > Cycletrol-150 DC controller. The am using the analog out from the
> 7i76 to replace the potentiometer to control the spindle speed. I have a 100 
> slot encoder with index (homemade) on the spindle.
> >
> > The spindle starts under LCNC control but I am not getting an �at speed 
> > indication� at above about 100rpm. The motor sounds like
> is is running at a steady speed but the Spindle Speed indicator fluctuates 
> wildly. I am suspicious of the spindle encoder. Before I was
> just running it as a 100 count counter with index and it worked fine. I can�t 
> figure out in PNCConf how to set up a spindle counter
> with index for the 7i76.
> >
> >> From: "John Dammeyer" 
> >>
> >> Hi Alan,
> >>
> >> This is what I found for a Cycletrol DC motor controller.
> >> http://www.grahammotorandcontrols.com/item_dc_motor_controller/176B6002/58
> >>
> >>
> >> There is no guarantee that a PWM output will emulate a potentiometer.  
> >> That's the first place to look
> >> First put the pot back and measure the voltage between the wiper and 
> >> ground as you control the speed from 0 to full RPM open
> loop.  And depending on how it's powered be careful that the pot inputs 
> aren't indirectly connected to ground.
> >>
> >> It's always possible the speed control won't work unless there is also 5K 
> >> Ohm between pin 9 and 11.
> >>
> >> It's also possible the pot changes the resistance (as a rheostat) in a 
> >> feedback circuit so input PWM may or may not work.
> >>
> >> Also PWM is exactly that pulse width.  Unless you have a filter capacitor 
> >> across that with a bleeder resistor to ground (Pin 11) the
> internal circuit many not integrate the PWM enough for it to work.
> >>
> >> For example I bought a small Chinese PWM to 0-10V module that has the rule 
> >> that the PWM frequency can't be higher than 1kHz.
> Try it with 10kHz and it won't create a lower voltage.  So PWM frequency is a 
> parameter that must be correct.
> >>
> >> I also, way back, bought a step/dir to 0-10V controller that produced 10V 
> >> at 25kHz step rate.  The problem was my ELS was
> limited to 20kHz so I never could get 10V out of it.
> >>
> >> I don't believe your 100 PPR encoder is the issue.  I'm running my spindle 
> >> with 60 PPR and can do power tapping on the mill.
> >>
> >> It may still be possible to find these UHU or HP_UHU kits somewhere.  I 
> >> ended up using them because the GECKO servo drives I
> bought were only good to 80V and my servo motors like more than 90V.  The 
> HP_UHU kit was good to over 200VDC.
> >> https://www.cnczone.com/forums/servo-motors-drives/342836-uhu-servo-controller-build.html
> >>
> >>
> >> Similarly there are still some STMBL kits out there.  These can actually 
> >> take the smart serial input from the MESA boards or
> step/dir.  I'm not sure that 0-10V was very implemented.
> >> https://www.pcbway.com/project/shareproject/stmbl_servo_motor_drive.html
> >>
> >> John
> >>
> >>
> >>
> >> From: "Peter C. Wallace" 
> >>
> >> I would first check the A/B phasing and symmetry by monitoring the A and B 
> >> inputs with halscope when turning at a slow speed
> (say 100 RPM or less)
> >> The pins to monitor would be:
> >>
> >> hm2_5i25.0.encoder.00.input-a
> >> 

Re: [Emc-users] Spindle setup for 5i25/7i76

[Alan Condit]

John, Peter and Gene,

I have the Cycletrol-150 Manual. It says that you can replace the 5k ohm 
potentiometer with a 0-10v analog signal. The 7i76 manual says that you can use 
it to replace a 5k potentiometer control (0-10v). So that should work and 
indeed seems to be working. I have tried adjusting the detectors to 90°. I have 
an old Tectronix scope and they look pretty good there. It now has a solid “at 
speed indication” up to about 250rpm. So now I am suspecting that I don’t have 
the PNCConf configuration quite correct for the spindle. At the top of the 
range the Speed Indicator fluctuates from about 400 to 600 rpm while the motor 
sounds like it is holding dead steady.
One of my problems is that I don’t actually know what the rpm of the motor 
should be at 90volts. It is a Pacific Scientific motor rated 1.5hp at 110v DC.

Thanks,
Alan



> I built a new controller for my 9x20 lathe using a 5i25/7i76 combo. I thought 
> I had everything working but I still can’t get the spindle working correctly.
> I have a 1.5hp PMDC treadmill motor that I am controlling with a 
> Cycletrol-150 DC controller. The am using the analog out from the 7i76 to 
> replace the potentiometer to control the spindle speed. I have a 100 slot 
> encoder with index (homemade) on the spindle.
> 
> The spindle starts under LCNC control but I am not getting an “at speed 
> indication” at above about 100rpm. The motor sounds like is is running at a 
> steady speed but the Spindle Speed indicator fluctuates wildly. I am 
> suspicious of the spindle encoder. Before I was just running it as a 100 
> count counter with index and it worked fine. I can’t figure out in PNCConf 
> how to set up a spindle counter with index for the 7i76.
> 
>> From: "John Dammeyer" 
>> 
>> Hi Alan,
>> 
>> This is what I found for a Cycletrol DC motor controller.
>> http://www.grahammotorandcontrols.com/item_dc_motor_controller/176B6002/58
>> 
>> 
>> There is no guarantee that a PWM output will emulate a potentiometer.  
>> That's the first place to look
>> First put the pot back and measure the voltage between the wiper and ground 
>> as you control the speed from 0 to full RPM open loop.  And depending on how 
>> it's powered be careful that the pot inputs aren't indirectly connected to 
>> ground.
>> 
>> It's always possible the speed control won't work unless there is also 5K 
>> Ohm between pin 9 and 11.
>> 
>> It's also possible the pot changes the resistance (as a rheostat) in a 
>> feedback circuit so input PWM may or may not work.  
>> 
>> Also PWM is exactly that pulse width.  Unless you have a filter capacitor 
>> across that with a bleeder resistor to ground (Pin 11) the internal circuit 
>> many not integrate the PWM enough for it to work.  
>> 
>> For example I bought a small Chinese PWM to 0-10V module that has the rule 
>> that the PWM frequency can't be higher than 1kHz.  Try it with 10kHz and it 
>> won't create a lower voltage.  So PWM frequency is a parameter that must be 
>> correct.
>> 
>> I also, way back, bought a step/dir to 0-10V controller that produced 10V at 
>> 25kHz step rate.  The problem was my ELS was limited to 20kHz so I never 
>> could get 10V out of it.
>> 
>> I don't believe your 100 PPR encoder is the issue.  I'm running my spindle 
>> with 60 PPR and can do power tapping on the mill.  
>> 
>> It may still be possible to find these UHU or HP_UHU kits somewhere.  I 
>> ended up using them because the GECKO servo drives I bought were only good 
>> to 80V and my servo motors like more than 90V.  The HP_UHU kit was good to 
>> over 200VDC.
>> https://www.cnczone.com/forums/servo-motors-drives/342836-uhu-servo-controller-build.html
>> 
>> 
>> Similarly there are still some STMBL kits out there.  These can actually 
>> take the smart serial input from the MESA boards or step/dir.  I'm not sure 
>> that 0-10V was very implemented.
>> https://www.pcbway.com/project/shareproject/stmbl_servo_motor_drive.html
>> 
>> John
>> 
>> 
>> 
>> From: "Peter C. Wallace" 
>> 
>> I would first check the A/B phasing and symmetry by monitoring the A and B 
>> inputs with halscope when turning at a slow speed (say 100 RPM or less)
>> The pins to monitor would be:
>> 
>> hm2_5i25.0.encoder.00.input-a
>> hm2_5i25.0.encoder.00.input-b
>> 
>> Ideally both A and B should be square waves (50% duty cycle)
>> and have a 90 degree phase difference (A changes in the middle of B high and 
>> B low times and vice versa)
>> 
>> 
>> Peter Wallace
>> Mesa Electronics
>> 
>> 
>> 
>> From: Gene Heskett 
>> 
>> On Sunday 12 September 2021 17:49:43 Alan Condit wrote:
>> 
>> 
>> getting proper quadrature out of homemade stuff is a bear with 4 sore paws. 
>> I know, I done it about 3 times now. I would in your shoes do this which has 
>> worked really well here.
>> 
>> How many "gear shifts" do you have between the motor and the actual 
>> spindlle? You could probably do more than 2, but thats all the gears I have 
>> on my g0704. I have tally switches on that 

Re: [Emc-users] Debugging Python under LinuxCNC

[John Dammeyer]

I'll answer part of my own question but it doesn't answer how to debug Python 
programs launched by LCNC.

First of all it's now working!

These two lines
# Copies of CAN dataRelayImage = 0  # No relays set yet.
Mist_PWM = 0# Mister pump motor speed 0
Fan_PWM = 0 # Cooling fan off.

Should be:
# Copies of CAN data
RelayImage = 0  # No relays set yet.
Mist_PWM = 0# Mister pump motor speed 0
Fan_PWM = 0 # Cooling fan off.

Somehow in editing the new line between the commented line and the RelayImage 
was deleted.

No Error from the Python program to LCNC.  Other than that it did nothing.
Therefore
Send_PDO_2(RelayImage)  # Update device relays with default 
values.

The above line failed because RelayImage had not yet been defined.  

So the question still stands.  How to debug a Python program that has the 
statement
import hal

If I run ./serial-relays.py I get an error:
HAL: ERROR: duplicate component name 'serial-relays'
Traceback (most recent call last):
  File "./serial-relays.py", line 49, in 
  h = hal.component("serial-relays")
hal.error Invalid argument

Oh and what I did to get there was to replace the CANUSB with a Serial USB 
dongle and a null modem cable to connect to the COM1: of my PC.  Then see what 
it was sending as text commands using the ser.write() function and where it 
hung.  

Thanks
John

> -Original Message-
> From: John Dammeyer [mailto:jo...@autoartisans.com]
> Sent: September-13-21 12:46 PM
> To: Enhanced Machine Controller (EMC)
> Subject: [Emc-users] Debugging Python under LinuxCNC
> 
> The Python program I wrote includes hal.  I'm using a Pi4 with LinuxCNC to 
> test all this.  Thonny on the Pi4 will run a similar pySerial
> project that doesn't include hal and spits out CAN messages through the 
> CANUSB so my hardware works.
> 
> The original 'simple' version of serial_relays.py still works.
> 
> However, the latest upgraded serial_relays.py program does not work properly. 
>  I've been commenting out all sorts of stuff but still
> no luck.
> 
> How does one get diagnostics from a python program loaded in the hal file as
> loadusr -Wn serial-relays ./serial-relays.py
> 
> If I add print() statements where would they show up?  Or would they at all?
> 
> Suggestions?
> 
> Thanks
> John
> 
> 
> "ELS! Nothing else works as well for your Lathe"
> Automation Artisans Inc.
> www dot autoartisans dot com
> 
> 
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Re: [Emc-users] Suggestions for a retrofit.

[John Dammeyer]

John,
The work has already been done with the STMBL project.  The biggest issue with 
that one was the 3 phase motor driver was discontinued so that caused a bit of 
panic.  But it's an open source project that can use step/dir or smart serial 
from the MESA boards.

https://github.com/rene-dev/stmbl

John Dammeyer

> -Original Message-
> From: John Figie [mailto:zephyr9...@gmail.com]
> Sent: September-13-21 1:32 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Suggestions for a retrofit.
> 
> It's been a long time and I have not made much progress. Except now I am
> retired from my job as an electrical engineer. In my job I developed
> industrial PMAC servo drives for a leading industrial controls manufacturer
> located in Milwaukee. So to solve my servo amplifier problem I have decided
> to build my own and have already made significant progress. My homemade
> drives will be able to run either DC brush motors or in the future AC
> motors. I have a basic torque mode drive in the process of development but
> I am thinking I would like the drive to be a velocity mode drive.
> 
> My question now is how to interface to LinuxCNC? I really want to connect
> all of my I/O using the mesa ethernet cards like the 7I80. From the 7I80 it
> looks like there is a way to have SPI interfaces. It seems like the SPI
> would be one way to make a simple digital interface to my drives. The 7I80
> would send velocity commands and velocity feedback to the drives. The
> drives would return status and fault information back to LinuxCNC.
> 
> Is it possible for me to use the SPI interfaces with LinuxCNC in the way I
> have described? If so, how does one go about setting up the SPI interfaces
> and defining what data is passed back and forth? I am hoping Andy Pugh, PCW
> or someone that knows can comment.
> 
> LinuxCNC  <--Ethernet--> 7I80 -<> I/O inputs and outputs
>  |-<> SPI comms to
> servo amps  7I46?
>  | < encoder inputs for
> axis and MPGs
> 
> LinuxCNC with position loop only should be able to run with a slower 1mSec
> or maybe 500uSec thread and no other high speed thread would be needed. I
> may however need to get the velocity feedback to my servo drive at a faster
> rate for best/better performance.
> 
> My reason for wanting Ethernet is I do not have to have my LinuxCNC PC on
> or embedded in my machine, it can be several meters away mounted where it
> won't be subject to heat and vibration. In addition with only one
> interface, a PC upgrade or repair / swap is easy.
> 
> 
> Regards,
> 
> John Figie
> 
> 
> On Sun, Nov 29, 2020 at 6:47 PM dave engvall  wrote:
> 
> >
> >
> > On 11/27/20 10:52 AM, andy pugh wrote:
> > > On Fri, 27 Nov 2020 at 18:45, John Figie  wrote:
> > >
> > >> I think I am going to attempt to figure out what the parameters of my
> > motor
> > >> are and make a model to simulate my control loop. For hobby stuff I
> > think
> > >> LTspice may be good to model and simulate.
> > > I am not sure what you hope to gain from a model. The data to populate
> > > it would have to come from the actual machine, and at that point you
> > > might as well just get on with it.
> > >
> > IIRC early versions of emc had motor parameters, etc tacked on the the
> > end of the parameters for each axis. I don't know if any use was ever
> > made of that.
> > Maybe some of the early emc-ers with their memory still intact will
> > remember as well as a model to insert the data into.
> > Dave
> >
> > Just a comment: I've never had much success using torque mode: that
> > doesn't mean I should not go back and revisit it.
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> 
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Re: [Emc-users] Suggestions for a retrofit.

[John Figie]

It's been a long time and I have not made much progress. Except now I am
retired from my job as an electrical engineer. In my job I developed
industrial PMAC servo drives for a leading industrial controls manufacturer
located in Milwaukee. So to solve my servo amplifier problem I have decided
to build my own and have already made significant progress. My homemade
drives will be able to run either DC brush motors or in the future AC
motors. I have a basic torque mode drive in the process of development but
I am thinking I would like the drive to be a velocity mode drive.

My question now is how to interface to LinuxCNC? I really want to connect
all of my I/O using the mesa ethernet cards like the 7I80. From the 7I80 it
looks like there is a way to have SPI interfaces. It seems like the SPI
would be one way to make a simple digital interface to my drives. The 7I80
would send velocity commands and velocity feedback to the drives. The
drives would return status and fault information back to LinuxCNC.

Is it possible for me to use the SPI interfaces with LinuxCNC in the way I
have described? If so, how does one go about setting up the SPI interfaces
and defining what data is passed back and forth? I am hoping Andy Pugh, PCW
or someone that knows can comment.

LinuxCNC  <--Ethernet--> 7I80 -<> I/O inputs and outputs
 |-<> SPI comms to
servo amps  7I46?
 | < encoder inputs for
axis and MPGs

LinuxCNC with position loop only should be able to run with a slower 1mSec
or maybe 500uSec thread and no other high speed thread would be needed. I
may however need to get the velocity feedback to my servo drive at a faster
rate for best/better performance.

My reason for wanting Ethernet is I do not have to have my LinuxCNC PC on
or embedded in my machine, it can be several meters away mounted where it
won't be subject to heat and vibration. In addition with only one
interface, a PC upgrade or repair / swap is easy.


Regards,

John Figie


On Sun, Nov 29, 2020 at 6:47 PM dave engvall  wrote:

>
>
> On 11/27/20 10:52 AM, andy pugh wrote:
> > On Fri, 27 Nov 2020 at 18:45, John Figie  wrote:
> >
> >> I think I am going to attempt to figure out what the parameters of my
> motor
> >> are and make a model to simulate my control loop. For hobby stuff I
> think
> >> LTspice may be good to model and simulate.
> > I am not sure what you hope to gain from a model. The data to populate
> > it would have to come from the actual machine, and at that point you
> > might as well just get on with it.
> >
> IIRC early versions of emc had motor parameters, etc tacked on the the
> end of the parameters for each axis. I don't know if any use was ever
> made of that.
> Maybe some of the early emc-ers with their memory still intact will
> remember as well as a model to insert the data into.
> Dave
>
> Just a comment: I've never had much success using torque mode: that
> doesn't mean I should not go back and revisit it.
>
>
> ___
> Emc-users mailing list
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>

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[Emc-users] Debugging Python under LinuxCNC

[John Dammeyer]

The Python program I wrote includes hal.  I'm using a Pi4 with LinuxCNC to test 
all this.  Thonny on the Pi4 will run a similar pySerial project that doesn't 
include hal and spits out CAN messages through the CANUSB so my hardware works.
 
The original 'simple' version of serial_relays.py still works.
 
However, the latest upgraded serial_relays.py program does not work properly.  
I've been commenting out all sorts of stuff but still no luck.
 
How does one get diagnostics from a python program loaded in the hal file as
loadusr -Wn serial-relays ./serial-relays.py
 
If I add print() statements where would they show up?  Or would they at all?
 
Suggestions?
 
Thanks
John
 
 
"ELS! Nothing else works as well for your Lathe"
Automation Artisans Inc.
www dot autoartisans dot com 
 

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Re: [Emc-users] Minimally printed rotary. Initial torque testing..

[Chris Albertson]

Yes, I agree with the words below. I better way to measure torque is to
make a drumwrape a cable around it and lift a bucket.  Run the drum at
different PPMs and load the bucket until the drum slows from it's
programmed RPM.  THis will allow you to plot an RPM vs torque curve.

What you have with a torque wrench is only one point on that curve.   For a
stepper motor this is the "best case" point on the curve, all other points
would be lower. Static torque is important but mostly these drives are
meant to move.

Along to same line.  Measuring longevity under zero load is not as
interesting as if measured at say 50% of max torque and running it in both
directions.  I know, testing takes time.

That said, I'm watching these experiments closely because I want to make
some of these reduction drives myself.  I meed at least 100:1 reduction in
a very smallspace.  I want to use a motor like one of these (but likely
notthis exact one)  amazon.com/Hobbypower-1000kv-Brushless...

  The "1000 KV" means 1000 RPM per volt and it comes with a digital
controller.  I Would mount the motor almost inside the flex cut of the
harmonic drive and maek an effective 10KV motor system

On Mon, Sep 13, 2021 at 10:26 AM John Dammeyer 
wrote:

> Nice update.
> My math works out as follows:
> 35 lb-ft is 35 * 12"/ft * 16 oz/lb = 6720 oz-in.
> You said the ratio is 100:1 so that means to get 6720 you only input 67.2
> oz-in.  That's about 1/3 of what you suspect your motor can do.
>
> Something is wrong with this picture then.  Especially since you were
> effectively using static torque rather than the much lower torque when the
> motor is turning at say 400 RPM.  With micro-stepping you also get a
> reduction in full step torque because the max current is now 0.707 x full
> torque.  And without closed loop encoder feedback you can quite easily have
> to micro-step a number of times before you see physical motion.
>
> None of that matters other than that you have shown your mechanics can
> handle 35 lb-ft which is all in all pretty cool !
>
> John
>
>
>
>
> > -Original Message-
> > From: Sam Sokolik [mailto:samco...@gmail.com]
> > Sent: September-12-21 5:50 PM
> > To: Enhanced Machine Controller (EMC)
> > Subject: [Emc-users] Minimally printed rotary. Initial torque testing..
> >
> > Small update
> >
> > https://youtu.be/eW1GGI55Epc
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
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>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] Minimally printed rotary. Initial torque testing..

[Matthew Herd]

Friction and elasticity in the ring gear likely account for most of the
difference.  I would imagine that the elasticity in the gear would be a
fairly strong impediment to motion.  Though calculations seem to be too
much trouble.

On Mon, Sep 13, 2021 at 2:00 PM Sam Sokolik  wrote:

> I agree with the quick math I did yesterday...   But again I have no info
> on these steppers..
>
> And yes - I think it is totally usable at 35 ft-lbs..  there is some
> friction there also running the 'wave' generator...
>
> On Mon, Sep 13, 2021, 12:26 PM John Dammeyer 
> wrote:
>
> > Nice update.
> > My math works out as follows:
> > 35 lb-ft is 35 * 12"/ft * 16 oz/lb = 6720 oz-in.
> > You said the ratio is 100:1 so that means to get 6720 you only input 67.2
> > oz-in.  That's about 1/3 of what you suspect your motor can do.
> >
> > Something is wrong with this picture then.  Especially since you were
> > effectively using static torque rather than the much lower torque when
> the
> > motor is turning at say 400 RPM.  With micro-stepping you also get a
> > reduction in full step torque because the max current is now 0.707 x full
> > torque.  And without closed loop encoder feedback you can quite easily
> have
> > to micro-step a number of times before you see physical motion.
> >
> > None of that matters other than that you have shown your mechanics can
> > handle 35 lb-ft which is all in all pretty cool !
> >
> > John
> >
> >
> >
> >
> > > -Original Message-
> > > From: Sam Sokolik [mailto:samco...@gmail.com]
> > > Sent: September-12-21 5:50 PM
> > > To: Enhanced Machine Controller (EMC)
> > > Subject: [Emc-users] Minimally printed rotary. Initial torque testing..
> > >
> > > Small update
> > >
> > > https://youtu.be/eW1GGI55Epc
> > >
> > > ___
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> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> >
> >
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> >
>
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-- 
Matthew Herd
Email:  herd.m...@gmail.com
Cell:  610-608-8930

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Re: [Emc-users] Minimally printed rotary. Initial torque testing..

[Sam Sokolik]

I agree with the quick math I did yesterday...   But again I have no info
on these steppers..

And yes - I think it is totally usable at 35 ft-lbs..  there is some
friction there also running the 'wave' generator...

On Mon, Sep 13, 2021, 12:26 PM John Dammeyer  wrote:

> Nice update.
> My math works out as follows:
> 35 lb-ft is 35 * 12"/ft * 16 oz/lb = 6720 oz-in.
> You said the ratio is 100:1 so that means to get 6720 you only input 67.2
> oz-in.  That's about 1/3 of what you suspect your motor can do.
>
> Something is wrong with this picture then.  Especially since you were
> effectively using static torque rather than the much lower torque when the
> motor is turning at say 400 RPM.  With micro-stepping you also get a
> reduction in full step torque because the max current is now 0.707 x full
> torque.  And without closed loop encoder feedback you can quite easily have
> to micro-step a number of times before you see physical motion.
>
> None of that matters other than that you have shown your mechanics can
> handle 35 lb-ft which is all in all pretty cool !
>
> John
>
>
>
>
> > -Original Message-
> > From: Sam Sokolik [mailto:samco...@gmail.com]
> > Sent: September-12-21 5:50 PM
> > To: Enhanced Machine Controller (EMC)
> > Subject: [Emc-users] Minimally printed rotary. Initial torque testing..
> >
> > Small update
> >
> > https://youtu.be/eW1GGI55Epc
> >
> > ___
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
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Re: [Emc-users] Minimally printed rotary. Initial torque testing..

[John Dammeyer]

Nice update.  
My math works out as follows:
35 lb-ft is 35 * 12"/ft * 16 oz/lb = 6720 oz-in.
You said the ratio is 100:1 so that means to get 6720 you only input 67.2 
oz-in.  That's about 1/3 of what you suspect your motor can do.  

Something is wrong with this picture then.  Especially since you were 
effectively using static torque rather than the much lower torque when the 
motor is turning at say 400 RPM.  With micro-stepping you also get a reduction 
in full step torque because the max current is now 0.707 x full torque.  And 
without closed loop encoder feedback you can quite easily have to micro-step a 
number of times before you see physical motion.

None of that matters other than that you have shown your mechanics can handle 
35 lb-ft which is all in all pretty cool !

John




> -Original Message-
> From: Sam Sokolik [mailto:samco...@gmail.com]
> Sent: September-12-21 5:50 PM
> To: Enhanced Machine Controller (EMC)
> Subject: [Emc-users] Minimally printed rotary. Initial torque testing..
> 
> Small update
> 
> https://youtu.be/eW1GGI55Epc
> 
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Re: [Emc-users] Minimally printed rotary. Initial torque testing..

[Gene Heskett]

On Monday 13 September 2021 06:00:25 Gregg Eshelman via Emc-users wrote:

> You almost sound disappointed that you couldn't break it. ;)

I noticed that too. I haven't broken my version but once, tried to make 
it from PLA, but I had a different idea because I wanted a smaller 
version, and I have the attitude that I can print another for 10 bucks 
worth of plastic and 3 bucks worth of bb's.  But since I switched to 
PETG, and that caused a few thou $ in printers to find one that could 
handle a steady diet of PETG, most can't. But PETG can make a very 
servicable loose belt as its lots more flexible than PLA. But in the 
interests of cheap, I didn't use an armature with off the shelf 
bearings. My armature is printed, including the hub which because the 
motor I chose has an 8mm shaft that I put on the 0704's table and ground 
the d-flat much wider, needs no alu or steel insert hub, the PETG as a 
press fit on the 8mm shaft has not failed. That armature is printed, and 
eccentric by 1.1mm. Its wrapped by two printed ball bearings, which in 
turn distort the loose belt in the same manner that Sam's much more 
expensive off the shelf bearings do. Probably with less flex stress on 
the loose belt because the push is fully distributed.

The drive I made is aimed at the A drive supplied with cheap gantry mills 
as the kit supplied has virtually zero holding power and 100x the rpms 
needed for such duties. Designed for a 30/1 ratio, and another nominally 
4/1 between it and the A axle, by way of a small pitch timing belt. Its 
a hair loose and needs a tensioner idler designed and built that I 
haven't found the round tuit to do yet.

I've had it running on the kitchen counter at about 3 rpm at the chuck 
for something over a month now. All except the bearing balls which are 
crosmann bb's, is 3d printed. Currently driven by a 1NM 3 phase 
stepper/servo, I think it will do the job on my 6040 mill. And if I 
break it, a $20 bill prints another. Its also got about an hours worth 
of running at just short of that small motors stall speed, 2000+ rpms 
for about a minute at a time so the armature bearings don't get too hot.  
At that speed, the bb's are probably spinning in the 100,000 rpms 
category.

The output end houseing and shaft only have 1 bearing,, another row of 
bb's, 75mm in diameter. There is more flex in the 3mm thick disk holding 
the output sprocket than anyplace else. It is less than 4" in diameter, 
and under 20mm thick not including the output sprocket, it is plenty 
strong enough to do _that_ job.
>
>On Sunday, September 12, 2021, 06:52:23 PM MDT, Sam Sokolik
>  wrote:
>
>  Small update
>
> https://youtu.be/eW1GGI55Epc
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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)
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] Minimally printed rotary. Initial torque testing..

[Gregg Eshelman via Emc-users]

You almost sound disappointed that you couldn't break it. ;)


   On Sunday, September 12, 2021, 06:52:23 PM MDT, Sam Sokolik 
 wrote:  
 
 Small update

https://youtu.be/eW1GGI55Epc  
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