Quote Originally Posted by JAZZCNC View Post
If by vector control you mean current recirculation while stood still then yes they do.
No, I mean vector control. I wont try and explain as it's a tricky one:

http://en.wikipedia.org/wiki/Vector_control_(motor)

http://www.eng-tips.com/faqs.cfm?fid=1062

Quote Originally Posted by JAZZCNC View Post
Only really apply's if your motors are good for the extra voltage.? Most nema 23's are not when wired parallel.!! . . . . Over rating a motors voltage will give extra speed but it also creates extra heat, iron loses etc which then slowly damages the motor shortening strength and life.
Mocha is using the same motors as I am, or at least very similar - 3Nm Nema 23 with low inductance. I've been running mine on 75V since I got them well over a year ago with no ill effects. The highest temperature I have ever recorded was 60 celcius (so at least 25C below rated) on the case which was on a sunny day when the machine had been running for a couple of hours. Most of the time they linger around 45C. I check it regularly as I have an infra-red thermometer to hand and it's something to do whilst the machine's running...good for getting estimate of cutter temperature too.