Intermediate sized holes, how to make them (what tool)?

francist said:
Electrical knockout punch (aka chassis punch)? Greenlee makes some as do others and 1-1/4” size is commonly available. Rated for 10ga steel so might do 1/8” aluminum? I’d wonder about potential distortion though if the holes are closely spaced.

-frank

View attachment 335629
Click to expand...
The holes are 1.25"OD spaced at 1.500", that has me worried, especially in 1/8" aluminum. If I had the punch, I'd try a test piece. I do know I'd have to use a drill or something. 40 holes is a lot of hand punching. Actually more concerned with having all the holes spaced evenly.
 
Karl_T said:
here's the cats' meow
www.ebay.com

Steel Dragon Tools® 1-1/4" x 1" HSS Annular Cutter with 3/4" Weldon Shank 817482024901 | eBay

Steel Dragon Tools® 1-1/4" x 1" High Speed Steel Annular Cutter with 3/4" Weldon Shank. 1 1/4" x 1" depth of cut HSS annular cutter. 1 1/4" x 1" depth of cut high-speed steel annular cutter. 3/4" Weldon Shank.
www.ebay.com
Click to expand...
That's pretty nice! Can one hold the weldon shank with an R8 collet? Seems like there's not much for the collet to grab. Even if I have to buy an adapter, that should cut a lot nicer hole than the hole saws I've been looking at.
 
I have cut holes in aluminum with the standard hole saw with no problems. You want to lub it with wd-40 or kerosene and not overdue the speed. Make sure the material is well clamped down don't try to hold it by hand.
 
Nutfarmer said:
I have cut holes in aluminum with the standard hole saw with no problems. You want to lub it with wd-40 or kerosene and not overdue the speed. Make sure the material is well clamped down don't try to hold it by hand.
Click to expand...
I'd never try this unclamped, don't have a death wish! Doing this on a mill, one would want a sacrificial board on both sizes? and really clamped down.
 
My vote is for the annular cutter.
Fasten a piece of 3/4 inch piece of plywood to the mill table and fasten the aluminum securely to the plywood and maybe use a couple of strap clamps by the hole you are cutting. If the mill is not strong enough lock the spindle in the clear up position and use the table raising crank to do the cutting.
This should give you the best possible finish on your finished holes!
I cut 2" holes through 2" CRS with no issues using an old Bridgeport!
 
40 holes is a lot. The traditional way would be to use a boring head, but it will be too slow for so many reps. Would give you the best results, though.

I've made more holes than I care to admit in aluminum using a hole saw. It's a slow, messy job, lots of WD40 and alloy slurry. It makes sh!tty holes, but they can be cleaned up with a boring bar...

The annular cutter would be the cat's meow.
 
When I made a collet rack the hole saw cut the holes right at 1 1/4 size.
problem was I could not get the collets in and out with ease. I had to take a hand grinder to each hole to open them up a bit. So if I had to do again I would use a adjustable trepan tool and make the hole a little bigger.
It was as much work to open the tight holes as to make them in the first place.
Jim
 
Meow, meow, meow. Bought the annular cutter. Since it was relatively cheap, and I don't have a boring head yet, it made some sense.

Hole saws with big hand drills scare the daylights out of me. Had a colleague of me knocked unconscious when the hole saw grabbed and stopped but the drill machine didn't. Drill handle spun around and knock him out cold. I've had them grab, but fortunately not hit me. Don't like them.
 
You must log in or register to reply here.
Back
Top