On Tuesday 01 December 2015 14:58:57 Bruce Layne wrote: > On 12/01/2015 10:59 AM, Stephen Dubovsky wrote: > > I have a couple Compact5s and its definitely a brushed dc spindle > > motor. Using a KBC DC speed controller on one of them but I can't > > reverse it w/o adding some sort of DPDT relay and some time delays. > > You may find that you have accelerated wear on the brushes if you run > the spindle motor in reverse. Some brushed DC motors don't mind as > much as others, but some don't like to run in reverse at all. > I've not near the hours on these motors in reverse as in fwd, but ISTR the lathes motor is actually running in reverse (for the arrow on the motor) when running fwd. If there was any extra fireworks on the brushes, I haven't noticed them. The motor on the toy mill was reversible from the factory, and it hasn't minded.
Both of these motors have the brushes mounted straight out. Where they are mounted at an angle, I'd have to assume its much more critical. The OEM motor controller in the G0704 was restricting it to about 1250 revs in reverse. The grizzly tech said that was on purpose but refused to clarify the purpose. So far its happy as a clam at 2750 in either direction, which is about 500 faster than the OEM rated. I apparently did find a thermal interrupter in the motor that is not on the schematic, if I wind it up to wide open, aka about 2900, after about 5 minutes, it goes into a run 3 minutes, rest 1, run 3, rest 1 cycle. I purposely left it running like that for something over 1/2 hour with no change in that cadence. The motor itself wasn't warmed up by more than 15F over ambient doing it, so I came to the conclusion that if that didn't fry it, I wasn't going to dis it and remove it. Dissing PM field motors is hard on the PM's, the armature is a "keeper", so I may have the end bells off to replace a bearing, but the armature is not removed. Same comment applies to steppers, where the armature is the PM. Removing it from the field assembly will weaken it, or stands a very good chance of it. Thanks Bruce. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Go from Idea to Many App Stores Faster with Intel(R) XDK Give your users amazing mobile app experiences with Intel(R) XDK. Use one codebase in this all-in-one HTML5 development environment. Design, debug & build mobile apps & 2D/3D high-impact games for multiple OSs. http://pubads.g.doubleclick.net/gampad/clk?id=254741911&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
