[dowling177]

Question:

I am looking to buy two unipolar steppers for my x and y axis. My router that I am building will be used to cut 1/2 to 3/4 in plywood cross sections (accuracy is within 1/16 in). I am driving both axes by belts and my gantry weighs around 60 lbs. I have been told that I will need 800-1000 oz-in steppers to do this.

I need unipolar steppers b/c they will only work with the controller I want to buy. Since I am buying unipolar motors instead of bipolar motors does this mean the power/torque will only be half the amount that they are rated at?

[ger21]

When you say belts, do you mean like a rack and pinion? If so, you shouldn't need more than 300-400 oz steppers, unless you are building a big router and want to go really fast. I've heard of a 75lb gantry moving at over 100ipm with 120oz steppers.THere are a lot of variables involved.

What unipolar driver are you looking at? Why unipolar and not bipolar? Generally, with larger motors like you're talking about, Gecko's (bipolar) will provide the best performance.

Some motors are rated unipolar, some bipolar. You need to know how the motor is rated. If its rated bipolar, then you'll lose about 30% of the torque running it unipolar. (for an 8 wire motor)