Drilling Big Holes...

No pun intended but what are you guys using to drill those big holes for VU meters etc.? :wink:

hole saw..

http://en.wikipedia.org/wiki/Hole_saw

And for really big ones:



:?

Scroll saw.

i'd use the closest size punch first...they are always showing up on ebay...conduit punch kits from greenlee...

I vote for the stepped bit depending on size

For the larger stuff I have been using a jigsaw and had good success.

Prior to that I was drilling lots of tiny holes right after another. Then wiould file down to smooth.

I've used a hand hydraulic punch for holes up to 35mm in diameter in 3mm aluminium, but they're expensive (I temporarily purloined the punch kit from work :wink: ). Also used the non-hydraulic version where you tighten an allen bolt to pull the punch through the metal and gotten good results, although it's best to experiment a bit with them first as they tend to distort the edges of the cut slightly.

Anything larger or in thicker material is probably better done with a holesaw, although the cut isn't as neat. For quick and cheap results in material <3mm thick a stepped drill bit works well. Use cutting oil to stop the holesaw/stepped bit from chattering in the material when drilling.

I have a few Q-Max punches for XLR's and Noval/Octal valve holes.
For everything up to 20mm I have a few Unibits - stepped drill bits.
Bigger than the Octal socket, it's many small holes and a file !!

MM.

+1 on the step drill bit. Got one new from amazon for a couple dollars.

[quote author="pucho812"]
For the larger stuff I have been using a jigsaw and had good success.
[/quote]

Oh yes! I forgot the jigsaw. A lot easier and faster than drilling lots of small holes. And then smoothening the edges with a file or a dremel..

If you have a "workmate" and are cutting holes in 1HE or 2HE panels you can have him holding the panels a bit under the saw, so it doesn't get scratched, by fixing it in the notches in the middle.

Hmmm..har to put words. A picture says it all..

All sorts of great ideas guys, thank you! I have a few step drill bits. The largest being 1 3/8", but these VU meters go beyond that.

I guess the best would be to stay away from steel chassis when doing anything with a VU? Drilling steel is a pain as it is, but monkeying around without the right tools? Any ideas for steel while we're at it (aka Hammond chassis)? Small holes and a file? :sad:

steel...

Use blue paint tape and mask the area. Mark piece for hole, and measure twice. I mark a x on stuff that goes away.

Use stepper and drill a pilot hole big enough to fit a jigsaw blade in. Drill one hole at a minimum, possibly 4 evenly around the circle . Drill them so that the pilot holes are inside the masked area.

Use good quality saw & blades, and take your time. Blades should be for the material and more teeth per inch for a smoother cut.

The greenly punches work very good. for Diy use, the Harbor freight punches work fine and when on sale set you back $15 or so.


http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91201

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96718

As a Instrumentation/Electrician/Scada geek I punch a lot of round holes.

hey kazper,

how nice(or not so nice) are the holes with those manual punches?

I've been using a circle cutter for 20 years...

A cheap example can be found here:
http://www.rockler.com/product.cfm?page=11196&cookietest=1

you can find models with 2 or even 3 blades.
You can revert the blades if you need to make some big washers.

Works well with aluminium or soft steel if not too thick. I have made a 2" hole in a stainless steel chassis recently, but it was pain in the asz...

You definitly need a drill press with those, for precision, but also for SAFETY reasons! With an handheld drill, even in aluminium, if the blade brutaly stops, it can brake your arm! The drill press will just clutch out...

Use the lowest speed, some oil, and wear safety glasses...

Axel

In the beginning i did it like this:
http://www.gyraf.dk/gy_pd/1176/g1176_construct06.jpg
http://www.gyraf.dk/gy_pd/1176/g1176_construct07.jpg
http://www.gyraf.dk/gy_pd/1176/g1176_construct08.jpg

Works as long a you have a bezel around the vu. For anything else:
http://www.frontpanelexpress.com/

Yeah, try to stay away from steel. It fucks up your tools and wastes your precious time.

Although in the event of a hammond steel chassis, for a larger hole, try a jigsaw with a for-metal blade. You will dull that blade, but it's easy and cheap to replace. And much easier than seemingly-endless grinding with metal files.

Yes I agree, I'm thinking of leaving those Hammond's for "knob-only" projects. :wink: Steel is such a pain in the ass. Drilling through aluminum is like drilling butter, then you go from that to steel and you wished you never thought steel was such a cool idea. :twisted:

[quote author="abby normal"]Steel is such a pain in the ass.[/quote]

My mastering console has a back panel of steel.. Almost 30 XLR holes done with a step bit. :twisted:

steel...

Use blue paint tape and mask the area. Mark piece for hole, and measure twice. I mark a x on stuff that goes away.

Use stepper and drill a pilot hole big enough to fit a jigsaw blade in. Drill one hole at a minimum, possibly 4 evenly around the circle . Drill them so that the pilot holes are inside the masked area.

Click to expand...

just to add to this, if you have the step bit holesdrilled on the 4 corners then you don't have to make any sharp turns with the jigsaw... much better.
Sleeper

I'd still vote for a holesaw. For steel, just use a bi-metallic saw. They'll last for years cutting steel as long as you cut with the right speed and don't overheat the teeth.