Re: [CAD_CAM_EDM_DRO] Semi-homebrew PCB Router W/X-Y Table?

The AntiYuppie wrote:

> I just acquired a few New England Affiliated Technologies X-Y tables.
> I think the company was bought out and their part numbering schemes
> changed, but they are similar to the XY-8080 listed on their website
> (www.neat.com) and described in a PDF. I also got the
> driver/controllers for them (Oregon Microsystems 10 microsteps/step
> units). I know quite a bit about electronics, stepper motors,
> software, and PC's. I once did some interesting work with converting
> Gerber files to an antiquated automatic insertion machine for a
> company I worked for, under the direction of manufacturing and PCB
> engineers. I don't, however, know much about CNC. Gee, I wish my
> grandfather was still around, a foreman of a machine shop.
>
> My needs are pretty simple: I'd like to build a device to "route" PCB
> patterns from HP-GL or Postscript output. Maybe, do the drilling,
> too. And, maybe, do a little engraving on brass. I know its overkill,
> to say the least, to do this with this level of equipment, but, hey,
> this is what I've got to work with.
>
> Questions (Answers appreciated!!)
>
> 1. Is a Dremel on the Z axis really going to be able to "cut it"? Can
> it really take constant use?

A Dremel is a moderately acceptable hand grinder. It really is not
very good (many have rubber O-rings between the motor hosuing
and case to reduce vibration - this will make the spindle wander)
as a machine spindle. Also, the bearing life is in the tens of hours
at full speed.

> 2. Would it be totally stupid to get a "china cheap" drill press and
> mount the table to the bottom plate? I have some ideas for "pulling
> down" the drill press with a stepper and a jackscrew for drilling
> holes.

The bearings and chuck are not very good on these. If you are going to
route PC board traces, you probably want to drill them, too. You need
a high speed, very accurate running chuck for this duty. You also need
the high speed for the routing operation.

There ARE special high-speed or 'micro' drill presses that are designed
for the 10,000 - 25,000 RPM speed range, and the use of micro-size
drill bits.

Jon