I have a stepper motor driven by one of the new high current pololu drivers. It turns full revolution no problem (400 steps). However, if I tell it to turn 100 steps 4 times, it goes anywhere from 395-398 steps. Note: there's a disc attached to the top of the stepper motor so maybe the angular momentum has something to do with it but I'm still confused as to why it's working w/ 400 steps and not 4 x 100 steps.
*Poor soldering? It's globby but shiny. *I was unplugging the power supply and holding a transducer connected to a 400V square wave pulser and got a tiny shock.. however the driver is protected with a 100uF capacitor and the motor was not on
So what you guys think? Is the motor damaged or is the small disc (61.62 grams, circular, attached on middle) causing momentum problems?
I appreciate any feedback, thanks.