Re: [CAD_CAM_EDM_DRO] What size servos or steppers for a Bridgeport style mill?

Scott Yanke wrote:

> I know, I recently saw this question asked, but I didn't catch the
> responce
> (sorry). I just aquired a runout mill for free (the price was right
> and they
> even delivered it ;-) from the shop across the street. The motor runs
> and
> the rest of the mill seems to be in fair shape. It will be workable
> for what
> I want to do (+-.007). It used to have an Analam controll on it which
> they
> kept along with the servos and encoders (but they left all of the
> scales
> on.) I would like to make it my first CNC project useing EMC.
> What size steppers or servo's would you reccoment for the X, Y, and Z
> (quil)
> axises?

Since it already has linear scales, you should go with a servo system.
The motors are
not all that critical. What you want is a motor that provides
relatively smooth motion
at a low speed. Using it with either direct drive or about a 2:1 speed
reduction to the
leadscrew, you won't need over about 1000 RPM, but you want as much
torque
as possible at the lowest current. A motor designed for 1200 RPM at 48
-72 volts,
and a peak current of at least 5 Amps gives you a ballpark to aim for.

A 1/8 Hp continuous power rating is another figure to look for in the
motor.
there are a number of DC servo motors from open reel compuer tape drives

that are ideal for this application.

Jon