Re: noob question - stepper motor encoder
Originally Posted by
ger21
The problem here is that the stepper has already lost position, most likely because it didn't have enough power. So, if it didn't have enough power to go where it was supposed to go, how s it going to have enough power to make corrections?
Lost steps are often the result of a momentary failure. Vibration, resonance, binding that clears when shaken, the head hitting something, cutting head bouncing, etc... One lost step almost never causes the motor to just bind in place. Yes, there are stalls that do cause that, but that is the exception rather than the rule.
I do completely agree that the better solution is NOT feedback, but rather a larger or better motor / driver. But not for that reason. If you are going to stay with steppers, get one that has the power to do the job open loop, or switch to non-stepper motors with a servo controller. Putting a closed loop patch on a motor that is only there because it can be open loop is a bad idea.
James hosts the single best wiki page about steppers for CNC hobbyists on the net:
http://www.piclist.com/techref/io/steppers.htm Disagree? Tell him what's missing! ,o)