Rileyesi wrote:

Sorry, I accidentally sent the message before I was done blathering!

I need to make some 4-11/16 inch holes in an aluminum instrument panel. The
panel is 1/8 inch thick. In the past we have used a simple hole saw in a mill,
but those holes were 4-1/4 in diameter, so I was able to find a standard hole
saw size. So far, I have been unable to find a hole saw in the size I need.
We also punch and drill some smaller holes for a fuse (1/2 inch) and for an
8-32 tapped hole.

Those shold be easy to drill n the drill press. For the 1/2 inch hole you can
sharpen a 1/2" twist drill so it has a profile like a flat wood cutting "spade
drill" and it'll go through those aluminum panels in one shot.




Can anyone suggest a good way of producing the 4-11/16 diameter holes? We have
your basic drill presses, lathes, and a manual mill available to use.

You can use a single point circle cutter in the drill press. Just make sure you
clamp the work down firmly with a piece of plywood under it.

Here's a link to a picture of one. Lots of different manufacturers make cutters
just like it. Mine (I've had it for the last 50 years or so) is a Greenlee brand:

http://acmehardware.com/product_detail.aspx?sku=4357174

Good luck and Happy Holidays,

Jeff

--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place
the blame on."





The material I have is 6061-T6. I'm using that because that is what Digi-Key
sells, to be honest. If there is a better material (must be non-ferrous), I
would appreciate a recommendation as well as a source for 20 or so at 7 x 19
inches. We are in northeast Ohio, USA.

Thanks.




--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place
the blame on."