On Tue, 01 Nov 2005 15:55:21 -0500, Bill Schwab
wrote:

Hello all,

I need to make a hole for a D-shell connector in a plastic box, approx
6x3x2 inches. It is at least simlar to Radio Shack cataglog number
270-1803 (you can search for that number on www.radioshack.com in case
you want see what I have in mind), and I need to put the trapezoidal
hole in one of the ends.

Any thoughts on clamping the box such that the end suspended above the
table of a mill-drill is well supported? I suppose I could simply clamp
it in the vice, but that seems less than optimal.

There are punches for making D-shell holes, but the last I looked, each
size cost almost half what I paid for my mill (minus tooling, freight,
etc. g).

Obviously, once I clamp the box, I will have the joys of trying to
machine something that has non-orthogonal sides. One approach would be
to put the rotary base back on my vice. I could make a jig of some
sort, or simply get the corners right and fake the non-parallel edges.
Given that I have previously done this by hand with a dremel, it need
not be perfect. With that said, suggestions for doing it correctly will
be cheerfully read and quite possible used.

Bill

Easy. Just find or make a piece of wood that fits inside the box.
Clamp the fact to be milled to the piece of wood with at least two
clamps. I use small Kant-twist clamps for this. Grab the wood in
the mill vise. You'll mill thru the plastic into the wood a little.

For trapezoidal D-sub holes, don't try to mill the trapezoid. Just
mill straight ends, then run the mill far enough to make the wider
corners, using an endmil of radius similar to the radii of the
corners. You can then easily file away the remaining plastic to
make the trapezoid.