Re: [Emc-users] G540, trip pots and stepper motor temperatures.
Hi all; I wrote: > > When it was just sitting, the motor was hot to the touch. From reading > this list, one might think that running the motor might actually keep it > cooler. > > Anybody know why one stepper motor would be overheating? > Getting the right resistor in there, and tuning the trim pot made all the difference. I can't believe what that resistor (about double the ohms now at 830 ohms) did. Tuning the trim pot was an absolute breeze, and the motors are now just warm to the touch. Thank you; John A. Stewart. > -- Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] G540, trip pots and stepper motor temperatures.
Steve, Martin; I have been doing some "goofing" and think I might have found some (to me) interesting bits. The motors are 0.8A, 4.9 Ohms resistance, 3.3mH. (Circuitspecialists.com, 28BYGH501) I put in resistors, that I had kicking around, of approx 460 ohms, measured. (so sourcing 0.46A, if I figured that correctly from the G540 docs) Putting the step rate at 0.2mm/sec, adjusting the trim pots so that they are as quiet as possible, AND still tick over, seems to keep them quite cool. (I'm not sure what "cool" is with this design) Going down to the workshop for an hour or two of testing, but somehow it seems that that trim pot being misadjusted seemed to cause the overheating? I don't understand what that trim pot actually does. Also, will try to source correct resistors so that the motors actually are supplied with correct current. The power supply was measured at just under 40v output. (switching supply) I'll run it for an hour or two this evening, and see if the motors are cooler. Thanks for the suggestions to check the resistors - that could have been an issue. -- Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] G540, trip pots and stepper motor temperatures.
Do you have the correct value current set resistors in the DB9 connection to the motors? Martin > Date: Sun, 26 May 2013 14:19:14 -0400 > From: ivatt...@gmail.com > To: emc-users@lists.sourceforge.net > Subject: [Emc-users] G540, trip pots and stepper motor temperatures. > > I'm getting my little Unimat CNC lathe going, and am doing axis running > tests; right now working on the Z axis (carriage movement) > > The X axis stepper is sitting idle, the Z axis stepper is running back and > forth. It is really hot to the touch, and one can smell hot insulation. > >From what I calculated, this NEMA-11 stepper motor has a motor voltage of > about 68 volts, running it on 48 volts. (the X axis stepper is slightly > smaller) > > When it was just sitting, the motor was hot to the touch. From reading this > list, one might think that running the motor might actually keep it cooler. > > Anybody know why one stepper motor would be overheating? > > (10mm/sec step rate, not overly fast) > > Yours truly, letting things cool off before trying anything else; > > John A. Stewart. > -- > Try New Relic Now & We'll Send You this Cool Shirt > New Relic is the only SaaS-based application performance monitoring service > that delivers powerful full stack analytics. Optimize and monitor your > browser, app, & servers with just a few lines of code. Try New Relic > and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] G540, trip pots and stepper motor temperatures.
What is the winding inductance of the motors? NEMA 17 and NEMA 11 motors sometimes have really low inductance. This causes the current to rise and fall in the windings with each PWM cycle. The result can be heating of the iron due to hysteresis losses. This can be counteracted by using a lower supply voltage or an external inductor to increase the apparent inductance of the motor. Steve Stallings > -Original Message- > From: John Stewart [mailto:ivatt...@gmail.com] > Sent: Sunday, May 26, 2013 2:19 PM > To: Enhanced Machine Controller (EMC) > Subject: [Emc-users] G540, trip pots and stepper motor temperatures. > > I'm getting my little Unimat CNC lathe going, and am doing > axis running > tests; right now working on the Z axis (carriage movement) > > The X axis stepper is sitting idle, the Z axis stepper is > running back and > forth. It is really hot to the touch, and one can smell hot > insulation. > >From what I calculated, this NEMA-11 stepper motor has a > motor voltage of > about 68 volts, running it on 48 volts. (the X axis stepper > is slightly > smaller) > > When it was just sitting, the motor was hot to the touch. > From reading this > list, one might think that running the motor might actually > keep it cooler. > > Anybody know why one stepper motor would be overheating? > > (10mm/sec step rate, not overly fast) > > Yours truly, letting things cool off before trying anything else; > > John A. Stewart. > -- -- Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] G540, trip pots and stepper motor temperatures.
I'm getting my little Unimat CNC lathe going, and am doing axis running tests; right now working on the Z axis (carriage movement) The X axis stepper is sitting idle, the Z axis stepper is running back and forth. It is really hot to the touch, and one can smell hot insulation. >From what I calculated, this NEMA-11 stepper motor has a motor voltage of about 68 volts, running it on 48 volts. (the X axis stepper is slightly smaller) When it was just sitting, the motor was hot to the touch. From reading this list, one might think that running the motor might actually keep it cooler. Anybody know why one stepper motor would be overheating? (10mm/sec step rate, not overly fast) Yours truly, letting things cool off before trying anything else; John A. Stewart. -- Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
