Brilliantly simple - why didn't I think of that :-). My motor generates 34N force for 45W power dissipation, for a motor constant Km of 5.0. My FEMM simulation indicated I should have had a Km of 7.7 or 52N of force for the same power, so I'm a bit low. I need to see if my magnets actually have the strength expected by the simulation library.
Repeatability looks very good. Worst case difference moving to a point a half dozen times was 1.1um. The other end of the move had a worst case difference of 4.8um. Later I'll set up some automated testing to collect a larger sample of data. -- Ralph ________________________________________ From: Viesturs Lācis [viesturs.la...@gmail.com] Sent: Friday, July 06, 2012 12:31 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] linear motor tuning questions 2012/7/6 Ralph Stirling <ralph.stirl...@wallawalla.edu>: > I'm looking forward to answers to those questions myself :-). > Theoretically the AS5311 encoders have 2um resolution. I am > going to be doing some repeatability testing tomorrow with an > LVDT to try to verify the encoder performance. Force measurement > is a little bit tricky, as driving it to stall causes an instant > following error. Simply set the ferror limit to some extremely large value, like 100 mm or so and then simply hang in a dynamo-meter to measure the force it can achieve. -- Viesturs If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
