Stepper selection. Sorry I know I know

[flash319]

I have been reading and doing calculation and I am still not satisfied with what I should get from Keling. I have a 100-130lb gantry that I want to mount 2 steppers on either side to drive it, rack and pinion. I want to cut at 3-500 IPM and rapid at 1000IPM at least. I was thinking about 2 of the NEMA 34 670oz/in motors. I would like to do it with no reduction if possible. What do you think?

[ger21]

What kind of resolution do you want, and what's the pitch diameter?

[flash319]

.005 would be good or better and the pitch is 1".

[johnmac]

If you get your 100+ LB gantry that fast with a direct drive rack & pinion setup, how are you going to get it stopped? Will you have a problem with the momentum of the gantry trying to overrun the steppers? My gantry is about 150 LB, but I have a ball screw that acts as a brake.

John

[jsheerin]

Your motors slow the gantry down by applying torque in the opposite direction they did to accelerate it. It should take the same torque to stop as to start. Actually it would take a bit less, as drag would help it stop. So if you have an acceleration value that works for speeding up, it should work for slowing down as well.