Re: Large stepper sources or size part 2

Karl:

I'm converting a 9x42 Bridgeport clone to CNC. So far I have the X and
Y going and they seem to work fine. I did retrofit ball screws for
these axes.

From my looking around I found it common to use about 650 oz-in motors
with a 2 to 1 reduction on this size machine. I ended up getting 750
oz-in motors from Camtronics along with the drivers.

If this is about right you'll need (650*2) 1300 oz-in or larger steppers
for direct drive. So that's one reference point. :-)

On 4 Oct, karl@... wrote:
> Thanks for the reference to the Camas stepper size calculator.
> Bridgeport must know how to size steppers. For a full size knee mill,
> this calculator calls for a 2000 oz/in stepper, assuming no gear
> reduction and a 250 lb. load. The calculator is very sensative to
> these two numbers. I'd like fast rapid traverse so I don't want to
> gear reduce, and the table and vise must weigh at least 150 lbs. so I
> can't go mush lower on the weight assumption.

> P.S. Is anybody getting by with much smaller steppers on a full size
> knee mill?
>
> Karl

--
Hugh Currin
Klamath Falls, OR