New Ballscrew Pitch?

[barkster]

I bought the ballscrews a long time ago when I first got into gathering stuff to build my cnc router. Now that I'm finally getting around to start building it I think these ballscrews may have too much pitch. I don't know the exact pitch because these must be custom. It looks like about 2.25 turn for an inch. They are 53" long and have no backlash and they are great screws but I think I would need some really strong steppers. What do you guys think?

[HuFlungDung]

Looks like 2.5 tpi from here, but you can best tell over a distance of several inches.

It shouldn't be too bad. You can always use a reduction ratio off your stepper to achieve the effect of getting more torque.

[barkster]

Yeah, does anyone have source for aquiring some belt drive pulleys and belts? I'll take a closer look at the screw and see what it looks like over a distance. Thanks

[ger21]

http://www.sdp-si.com/

[barkster]

Thanks, I'll check them out. If these come out to 2.5tpi and I'm using say a 300oz stepper any suggestions on a good ratio? Thanks

[Cold Fusion]

A low TPI isn't a bad thing. As long as you gear it down and use the proper motors, it can work to your advantage. I use 20mm per turn Ballscrews, geared down 24:36 with 700oz steppers and it has plenty of torque with amazing rapids.