I have spent a lot of time trying to find out what is appropriate for my application, many people seem to dismiss the idea of using a encoder with a stepper.
I am building a cnc wire cutter/stripper, using a linkage mechanism in conjuction with a sparkfun stepper motor to generate a linear motion that drives stripper blades. I would really like to have an encoder to know if a step is missed. I am microstepping the stepper at 1/16, so .11 degrees resolution. I would like something that easy to attach to the motor. Sparkfun had encoders but told me that werent really designed to be used with stepper motors.
What is a recommended stepper encoder combination? My budget is about $50, I would like a reliable stepper motor that isnt low quality, the torque isnt that much of a problem.
Also, what would be a good homing sensor for the linear travel, it needs to be something that can instantly return so i my position isnt off my more than .0005".
I reckon if you need an encoder to verify the position of a stepper you aren't using the stepper properly or you are using a stepper that is not powerful enough for the application. Maybe you need reduction gears in place of microsteps.
The whole point of using a stepper is being able to rely on the steps to give the correct position.
Most applications will also have switch (microswitch or optical detector) to identify the HOME position and allow the code to know when the stepper is physically at the ZERO step position.
Well the price isnt that big of a deal, I was wondering if there was an attachment that I could put on a lower cost stepper, even if it was less that $100 that would be fine.
I dont think torque is an issue, ive done some experiments and i should have plenty. I just want to design my device to not fail, and I was excited by the idea of tinkering with position feedback.
As far as a zero home position, I have done a little with break beam sensors. What is a good strategy for getting an accurate home position, what about with and without a hard stop? I have two opposing blades sliding linear along a track.
What about having a two thru holes lining up and sampling the adc after each pulse of the stepper, looking for the the point at which the adc starts to decrease?