2:1 or 3:1 reduction...I'm not sure?

[Bird_E]

I going to convert my X3 to CNC. I'm considering using some of the "Cheap"
clifton servo motors at 360/oz-in PEAK. Will these motors have enough power in a 2:1 ratio or should I go to 3:1? Peak RPM is about 2700

Thanks!
Bob

[kong]

Well, if you use 3:1, then max rpm will be 900. So on a 5TPI screw, that will give a max speed of 180 IPM! Are you needing more speed

[Bird_E]

No, I don't need more speed, but what about torque? I guess my real question is, what would be the best ratio so that torque is enough without killing the motors and also have decent speed?
Thanks!
Bob

[kong]

I don't realy know the size of the mill, but I reckon 3:1 would be fine with a peak torque of over 1000 oz/in. Hopefully someone with more knowledge of that mill will chime in soon.

[Bird_E]

I don't realy know the size of the mill, but I reckon 3:1 would be fine with a peak torque of over 1000 oz/in. Hopefully someone with more knowledge of that mill will chime in soon.

The Mill Size is bigger then a mini mill, may be a little smaller then a mill/drill
about 300 lbs. if that helps!
Bob

[kong]

Well, if it were me, I would go 3:1, it it certainly fast enough, and probably more torque than your spindle can cope with anyhow You could even go 4:1, but then you get the problem of the pulleys being too big! Yep, 3:1 is good.