On Thu, 27 Mar 2014, Florian Rist wrote: > Date: Thu, 27 Mar 2014 18:31:12 +0100 > From: Florian Rist <fr...@fs.tum.de> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: [Emc-users] BLDC Servo Torque Problem? > > Hi, > I have some problems in setting up BLDC servos, I just don't manage to > get enough torque. Here's the set-up: > > Intel D525MW > Mesa 5i23 > Mesa 7i39-LV > Nanotec DB57L01 + 4000 CPR endoder > > The servos are rated 24V DC, 4.6A (peak 17A). My power supply is 24V DC > SNT rated at 500W. > > I suppose I just don't get the PID settings right, but before > investigating this a question regarding power supply: > > Is the 24V supply correct? Or do I misread the BLDC data sheet and the > 24V is a RMS rating? > > cu > Flo >
The 7I39LV is limited to 30VDC max Its hard to tell with motor specifications, sometimes they are RMS and sometimes they are DC (for example lots of large BLDC motors are rated 320V which actually means they are 220V AC motors) If you dont have enough torque, a couple things to check are 1. initial rotor alignment (if wrong you will have different torque each direction) 2. Make sure the deadtime is set to 0 3. Make sure the PWM rate is set fairly high so you dont get current limiting from ripple current (40KHz is good for 7I39s) 4. Make sure you have the 7I39 current limit set to 15A and not 7.5A 5. If you have problems at high speeds, consider running LinuxCNC master and raising the servo thread rate as high as you can (good MBs can do 4 KHz or better) (linuxcnc master has a patch to BLDC than extrapolates the commutation angle base on velocity so approximately halves the commutation angle error at high speeds) > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
