On Wednesday, December 28, 2011 12:05:13 PM Dave Caroline did opine: > I assume all my steppers are using all the amps I want them to, which > would be 12A if I was using 4 steppers at 3A ea.
Not so Dave. For modern chopper stabilized current controlling drivers, the power supply is only supplying the resistance and eddy current losses in the motor and driver. Worst case for really old motors with lossy iron might be 50% of the nameplate current that actually comes from the supply _once_ the current setting has been reached at initial power-up. > But probotix is probably assuming some reduction in current while > stationary this can lead to loss of position when powered down to a > lower current (it may be a requirement if insufficient heatsink is > provided). I have been amazed at how cool my motors run on the MM-542 drivers, and equally amazed at the torque it takes to turn them a full step when powered down to 50% current when idle. Yes, I _can_ turn them but they will not get moved by accident... Brushing an arm or belly against the resonance damper while hand changing tooling sure isn't going to do it. > This may be ok for some operations but not all. > > Dave Caroline 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> We'll know that rock is dead when you have to get a degree to work in it. ------------------------------------------------------------------------------ Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex infrastructure or vast IT resources to deliver seamless, secure access to virtual desktops. With this all-in-one solution, easily deploy virtual desktops for less than the cost of PCs and save 60% on VDI infrastructure costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
