Re: Help?? CNC PCB Drilling Machine

Depending on what machine tools you have I would go for:

Mdf frame construction (or Ali if you have the skill/tools)

Silver steel or ground steel linear rails (not so expensive)

Home made Delrin (acetal) slides (basically reamed rod to fit rail)

1mm pitch 6mm threaded rod for a leadscrew (assuming ultra accuracy
not needed)

Nylon/Delrin Lead nut, long enough to elliminate backlash.

Nema23 steppers, you don't need 100oz-in even because of what you are
doing. Get bipolar and don't get high voltage ones.

Good three axis driver kits include camtronics and Xytolex these run
from the parralel port and use free driver software such as TurboCNC.

Alternately you could use ebay to get some better mechanical
components. Either way you may find it the cheapest place to buy the
steppers.


Links of interest:

http://home.hccnet.nl/m.de.roode/

Lots of interesting stuff on cnc engravers which is essentially what
you are building

http://www.seanet.com/~dmauch/

Source of camtronics 2amp bipolar stepper driver kit.

http://www.xylotex.com/

Source of the Xylotex three axis 2.5A driver board

http://www.dakeng.com/turbo.htm

Home of TurboCNC (I use this and it is good)

http://www.cadsoftusa.com/

Home of Eagle pcb design program, a free version is available and
there is a good support comunity.

To conclude: You can make a nice little machine that will drill pcbs
without much difficulty at all. The more acuracy you want the harder
it becomes or rather the more expensive.

Cheers,

Graham Stabler
Nottingham, England