On Sat, 6 Sep 2008 21:57:02 -0400, "Tom Gardner"
wrote:

I need about 67 rpm on a shaft.
An 1800 motor with a 40 to 1 gearbox = 45
An 1800 motor with a 20 to 1 gearbox = 90
Of course, Automation Direct doesn't have a 30 to 1 box and I want to use
them as a supplier.
The output of the gearbox will have a belt to drive the shaft but should I
use the 40 and step up the speed to the shaft with the appropriate sheaves
or step down the speed from the 20? Or, does it not make any difference?

Torque doesn't factor into this, I'm upgrading from 1/10hp single phase to
1/3hp 3-phase...and it's CHEAPER!!!


I'm a big fan of Automation Direct, but why are you stuck with them?
Oriental Motor makes small and smaller 3-phase gearmotors in just
about any power and ratio you could want. They stock the component
motors and gearheads to make just about anything they list. Figure
around $250 for a typical gear+motor.

http://catalog.orientalmotor.com/cat...rs-?&plpver=11

--
Ned Simmons