Drilling FR4/G10 Garolite

[jaysg]

Anyone use cutting oil?

[M Fowler]

No I do not use oil.

[sportster4eva]

Definitely don't use oil.
Definitely DO use gloves, or you wind up with itchy hands for a couple hours after... Trust me on that one.

A long time ago I made a drill press just for drilling PCB's using a PWM speed controller and a 24v permanent magnet motor from a big old IBM tape drive. It used preloaded ball bearings, so there's no end/side play whatsoever, and I found a coupler to connect a 1/4" chuck to it. I used ball bearing drawer slides for the vertical rails and a dot matrix printer belt and pulleys to raise and lower the head asembly, which is counterbalanced by a big spring. It's totally ghetto, but it works fantastically! I run it at about 3600-5000 rpm's and it makes nice holes with no tearout at the back even without a backer board. I did notice that after a couple hundred holes the HSS bits get slightly dull, but you can get the double-ended jobber bits for like $2.49 for 10, so no issue there.

[paulster]

I did notice that after a couple hundred holes the HSS bits get slightly dull, but you can get the double-ended jobber bits for like $2.49 for 10, so no issue there.

That's about what I've found with off-the-shelf HSS bits. I use a drill press and medium speed and don't get any tear-out without using a backing board.

As soon as the bottom edges start to get a little rough (after a couple of hundred holes) I swap the bit out before I start getting tear-out.

At the price they cost I can't complain.

[Noel Grassy]

Check out:
http://www.goldmine-elec.com/
They have #57-#69, boxes of 50, $45/box, if you're interested.
Lots on ebay.
These are quite easily broke with any lateral displacement.

Oh yeah, these are brittle, crystalline metal which would rather break than even be a drill bit sometimes. They are found in the surplus joints by
my place in boxes of 20~30 for $5 bux more often than not. It's a shame
that they cost so much every where else. My Pops used to sell these to
PCB fabbing shops but has since retired. He told me the other day that
he still has several shelves full of bits in boxes that he would like me to take. If shipping wasn't so cost prohibitive I'd offer these here for my cost.
Meaning free of course.

[Sonny ReVerb]

Definitely DO use gloves, or you wind up with itchy hands for a couple hours after... Trust me on that one.

Wearing gloves around a drill press is NOT recommended - safety wise. Most power tool safety sites advise against it. I just keep my hands away from the 'shavings'. A dust collector would probably be a great idea, if you have one. Otherwise, use a mask. I use relatively low speeds (800-900 rpm I think) which don't kick up much dust.

[Andy Le Blanc]

I've got my drill press in front of a window, and a fan in the window. The dust
is nasty. Latex glove are good for the itch. Break out on the side can be a pain.
I've found that a little touch up on the back side with a counter sink works nice.
The eyelet rolls down into the result very nicely.