[lazlo]

I'm not sure what sub-forum this belongs in, but I just picked up a couple of 140 oz/in. PacSci unipolar steppers that have nice HP optical shaft encoders on them (quadrature output).

What is the least expensive closed-loop setup I can cobble together?

Is there a quadrature input board for home CNC?

I'm told that Mach2 doesn't support closed-loop feedback -- what's the least expensive NC software that does support closed-loop feedback for steppers?

Thanks!

Robert

[ger21]

This is the only one I know of. http://www.maxnc.com/page5.html

[lazlo]

Wow, pretty expensive:

P/N 22155... 3 axis Motion Control System (single stack motors)……...…..$ 875.00

[Halfnutz]

I keep checking out servo (or closed loop stepper) systems and get shut down everytime when it gets to the price tag. Today I found some nema 34 servos with 1600 oz/in holding torque for 175.00 ea. And the prices keep coming down. Nema 23 double stacks w/ 280 oz/in for 50.00 from zylotec. 180 oz in for 39.00 and 116 oz/in for 19.00. I think Im gonna give up the servo thing and go with over powered steppers. The only time you need the closed loop is if your pushing too hard and missing steps as far as I can tell. Otherwise there is no gain in accuracy from what I have seen. Why bother with all of the hassle of tuning and the extra HW and cost?

[lazlo]

The only time you need the closed loop is if your pushing too hard and missing steps as far as I can tell. Otherwise there is no gain in accuracy from what I have seen. Why bother with all of the hassle of tuning and the extra HW and cost?

Good point. I just have these gorgeous HP shaft encoders on the steppers, and it kills me not to connect them to something