Re: [CAD_CAM_EDM_DRO] Newbie questions: Enco milling table conversion?

brainlessbill wrote:

> Hi everyone,
> I recently acquired an Enco drill/mill table at a great price from a
> friend. It is the one with the 11" x 7.5" travel. I plan on
> converting it for use with stepper so that I can perform some simple
> relief carving.
>
> Now for the question: Is there a rule of thumb for calculating the
> gear reduction that I will need in order to reliably use steppers
> with this table? I currently have some Vexta unipolar motors that
> are rated at 125 oz-in holding force. I just need to figure out the
> reduction I will need before I (a) have my friend turn a set of
> pulleys or (b) order a set of gears.
>
> Has anyone done this conversion? The slides have quite a bit of
> resistance, and I have a bad feeling that I won't be able to use my
> steppers...

This is for servos, rather than steppers, but almost all the steps of
the calculation are the same. The only difference is that you need to
add in the fall-off of torque with increasing speed of a stepper motor.
You need info from the manufacturer of the motor or drive, or you
can make approximations. So, take a look at < http://206.19.206.56/motor.htm >
from the CAD_CAM home page.

Jon