On Saturday, December 24, 2011 02:26:16 PM [email protected] did opine: > On Sat, 24 Dec 2011, gene heskett wrote: > > On Saturday, December 24, 2011 01:48:17 PM [email protected] did opine: > >> Probotix equipment > >> 40VDC 10Amp Linear Power Supply > >> PBX-RF RF Isolated CNC Breakout Board > >> 3 - Uni-polar Stepper Motor Chopper Drivers > > > > Specs on this driver board please? > > http://www.probotix.com/manuals/ProboStepVX.pdf > > >> 3 - 280 OzIn 8-Wire Stepper Motor > >> > >> I have run this setup for over a year with no problems, so I thought > >> I would create one I have a used Pacific Scientific Powermax II > >> stepper model P21NRXA-LNF-NS-00 I could not send the datasheet for > >> the motor so I sent the link to it > >> http://www.electromate.com/db_support/downloads/Nema23PowermaxII.pdf > > > > This data sheet shows 2 things, one that it does run hot, very hot. > > 130C in a 40C environment. To me that is too hot, but they know > > their varnish better than I do. Any other comments I'll wait for the > > driver specs to make. > > > >> I > >> added a 4th Uni-polar Stepper Motor Chopper Drivers > >> Wired motor and driver and they actually work > >> > >> Issue 1 > >> The motor gets VERY hot > >> I have run the other motors for a couple of hours and they got hot > >> but the SI motor will burn your fingers after about 15 minutes The > >> manual for the Uni-polar Stepper Motor Chopper Drivers says to set > >> the current limiter to .145 * target_current, 2.8 amps = .406 I > >> reduced it to .38 and it still gets too hot > >> > >> Issue 2 > >> The motor is slow > >> The label says max 1500 rpm but I can only get a fraction of that > >> I use EMC 2.4.6 > >> The driver is set to 1/8 stepping > >> > >> [AXIS_3] > >> TYPE = ANGULAR > >> HOME = 0.0 > >> MAX_VELOCITY = 360 > >> MAX_ACCELERATION = 5000.0 > >> STEPGEN_MAXACCEL = 6250.0 > >> SCALE = 4.44444444444 > >> FERROR = 1 > >> MIN_FERROR = .25 > >> MIN_LIMIT = -9999.0 > >> MAX_LIMIT = 9999.0 > >> HOME_OFFSET = 0.0
Off topic, from this I assume its running a rotary table? If that table has the usual 72 or 90 gear down, those settings are a bit off. >From one of my ini files that included a 425oz motor on a 4" Grizzly table, direct drive to the worm: [AXIS_3] TYPE = ANGULAR HOME = 0.0 MAX_VELOCITY = 81.8965517241 MAX_ACCELERATION = 1200.0 STEPGEN_MAXACCEL = 1500.0 SCALE = 200.0 FERROR = 1 MIN_FERROR = .25 MIN_LIMIT = -9999.0 MAX_LIMIT = 9999.0 HOME_OFFSET = 0.0 Now, some of those I will admit are swags, set higher than needed just to get the errors out of the way, but it works for the most part. The absolutes are max-vel, max-accel and stepgen-maxaccel else I got stalls. 28 volt supply to an xylotex driver board at the time. You have 40, so those could be scaled up perhaps 25%. IIRC the scale is wrong, it needs upping by the gear ratio IIRC but I need to start emc with that and recheck that. OTOH, I recall that I saw in axis, the same # of degrees the table moved. I know it needs a backlash setting plugged in, but I was so anxious to try it, the g-code I wrote was always coming to rest in the same direction. But that didn't help it when the cutting torque moved the table to take up the backlash either, and of course a backlash setting wouldn't help unless I incorporated a .001 degree step move in the other direction as the bit was starting down the other side of a sprockets tooth profile. But that is another story, the sprockets worked, with many thanks to Andy P. for some very elegant code. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> No one becomes depraved in a moment. -- Decimus Junius Juvenalis ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
