Re: [CAD_CAM_EDM_DRO] how to get started

I am in the process of buying and restoring a bridgeport mill and I would like to make it a cnc machine. It seems like a big task but others have done it so I can as well. 

Where is a good place to start?

Well, first, a CNC machine with a dead control is much easier to retrofit than
a manual machine.  You don't have to deal with installing ballscrews and
a quill drive to it.  But, if you have already taken the plunge, then you
need to retrofit some kind of low-backlash leadscrew to it.  Using the original,
and possibly badly worn, Acme screws is a VERY bad plan.  Generally,
they start with a lot of backlash, and the bronze nuts are so hard that
the middle of the screws develop a LOT of wear.  this causes a lot of
error in screw lead between the end and the middle.  On my mill
it was greater than .030" error due to the differential wear.  There's
no way to fix this with software.  I'd recommend a ballscrew retrofit
kit.

A Bridgeport is at the upper end of where steppers work, so you may
want to consider using servo motors.  A servo system won't cost
much more than a GOOD stepper and drive system.

<personal plug follows>
You can take a look at LinuxCNC
http://www.linuxcnc.org

 and the Pico Systems PWM servo system
http://pico-systems.com/osc2.5/catalog/index.php?cPath=3

Jon