On Wed, Apr 18, 2012 at 11:31 AM, Sergey Dryga wrote: > Denny Esterline gmail.com> writes: > > > Hmmmm... Possible I suppose. So I guess my next question is, How would > one > > go about creating the hall table? > > > > My procedure was to excite a winding pair at lowish current (by loading > one > > of my commutation states into OVDCON and setting 10% DC), waiting for t= he > > rotor to stabilize and reading out the current hall data. > > > > Just curious, is the connection diagram mfg provides not sufficient? > http://www.electrocraft.com/products/bldc/RP23/ > > I will probably use similar type motor in near future, this thread is > great to > find out potential problems they happen to me. > > No, that diagram shows a _ drive sequence_, but neglects to identify which wires connect to which phase and also completely lacks any phase data about the sensors. A different PDF I beat out of the rep has a bit more data. (not sure if I can share it though, it's not on their web site) I think I have this fixed. It's gonna take a bit more time than I have at the moment for a reasonable write up, but it seems that my sector table -> math -> commutation table was energizing coils about 45 degrees ahead in one direction and only about 20 degrees ahead in the other direction. And in the bad direction, it wasn't changing state until a few degrees past the zero torque point. So in essence, it was pulling backwards for some part of the cycle. Setting up a "protractor" and finding the coil points and the hall transition points was very enlightening. The hall sensors have _way_ more hysteresis than I suspected (over 15 degrees in some places) and the sensed points were far less symmetrical than I expected. -Denny --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .