Bongodrummer
Established Member
I keep finding working washing machine motors - always the brushed universal type, which seem to be everywhere. Has anyone else got example implementations of these motors on workshop tools? I have experimented with various speed control methods (and they DO need controlling - if hooked up to mains, unregulated their no-load speed is enough to damage the motors bearings, armature, and in worst case fly apart - don't stand too close!) for a number of DIY tools.
I have experimented making basic triac circuit variants in a lathe, disc sander and pillar drill, but in my latest project, a multipurpose rotary machine (mainly used as a green sand muller http://machine.construction/rotary_tool ), I had a crack at making and understanding an Arduino based, closed loop control circuit. While I found it theoretically straightforward - PID algorithm takes in Motors actual RPM, compares it to our desired set RPM, and triggers the triac accordingly - the implementation is proving tricky.
Here's a video of the speed control circuits - might be usefull for some folks. https://youtu.be/xI6CF2nYf_g?list=PL95E ... mEvzn5y3Nf
I have it working relatively well in RPM ranges from 1500 to 4000 (I don't need it to go higher, but doubt that would be a problem) . But below that speed I am struggling to get consistent performance from the motor/controller... Am getting phantom triac triggering etc. It's a long shot but anyone have experience fiddling with the tuning parameters of PID to give good performance at low speed?
I have experimented making basic triac circuit variants in a lathe, disc sander and pillar drill, but in my latest project, a multipurpose rotary machine (mainly used as a green sand muller http://machine.construction/rotary_tool ), I had a crack at making and understanding an Arduino based, closed loop control circuit. While I found it theoretically straightforward - PID algorithm takes in Motors actual RPM, compares it to our desired set RPM, and triggers the triac accordingly - the implementation is proving tricky.
Here's a video of the speed control circuits - might be usefull for some folks. https://youtu.be/xI6CF2nYf_g?list=PL95E ... mEvzn5y3Nf
I have it working relatively well in RPM ranges from 1500 to 4000 (I don't need it to go higher, but doubt that would be a problem) . But below that speed I am struggling to get consistent performance from the motor/controller... Am getting phantom triac triggering etc. It's a long shot but anyone have experience fiddling with the tuning parameters of PID to give good performance at low speed?