Tip: Instrument panel hole cutting

[szicree]

First I'd like to publicly thank Derrell Brooks for loaning me his hole punch all the way from Georgia to California for only the cost of shipping. Today I used it to punch all the round holes in my panel and gotta say that this tool is about as great as a tool can be. Perfect holes in about 30 seconds each with (almost) no chance of screw up. I'm attaching a pic of the tools I used and a quick outline of how I went about it.

First thing is to locate the intended centers of all instruments. This part took a long time but is really the only place things could get fouled up. Drill small pilot holes through each center and follow up with 5/8 inch unibit. Now comes the homemade part.

I made a little jig out of some scrap with a 5/8 inch hole in the middle and 1/8 inch holes where the mountings for instruments go. The dimensions were taken very carefully from actual parts, taking care that at least one of the long sides of the jig was parallel with a line through two of the mounting holes. Now just bolt the jig to the panel and use a square placed along the bottom edge of the panel to make sure it's vertical.

Next use a 1/8 inch bit in a hand drill to mark the panel for drilling later. It's not a great idea to drill through, since eventually this will tear up the jig. Repeat this for each instrument.

Next use the punch to poke all the holes. This thing works perfectly and allowed me to punch all the holes in about 10 minutes. Screw that fly-cutter B.S! The punch cuts the hole a hair on the small size so I used a little drum sander in my drill press to size them to perfection. A couple of laps around with a coarse grit followed by a clean up with a little scotch brite flap wheel and they were perfect. Making the cutout for the altimeter knob is still a pain, but what the heck.

Beg, borrow or steal one of these punches and you'll throw the fly-cutter in the trash (or at least the bottom of the tool drawer. Thanks again Derrell. I'll get it in the mail to ya this week.

Steve Zicree

[L.Adamson]

Originally Posted by szicree

Screw that fly-cutter B.S! The punch cuts the hole a hair on the small size so I used a little drum sander in my drill press to size them to perfection. A couple of laps around with a coarse grit followed by a clean up with a little scotch brite flap wheel and they were perfect.

I suppose these tools are fine, but I actually really do like the fly cutter. I've done two complete panels with one. I do have my own techniques, which someone might be interested in.

First, for the centering hole, I'd use a unibit to one size smaller than 3/8", and then a standard 3/8" drill bit to finish the hole. Of course, this would all depend on the fly-cutter pilot shank size. This provides a tight starter hole with no slop.

Then, I'd spin the fly cutter through a few revolutions by hand, on the top side of the panel to score the circle.

Flip the panel over, and litterly "plunge" cut the holes using 450 rpm on the drill press and "NO" oil. Just pull the handle to plunge into the material for a few revolutions, then lift & plunge again. The circles will pop out in a perfect diameter, and can be finished off with a slight hand rubbing of grey scothbrite pads. One advantage that I find with fly-cutting, is a much less chance of distorting the flat surface, that can sometimes happen with die cutters.

edit- use particle board under tha panel, with the pilot hole drilled in particle board also. And clamp everything.
Leather gloves, if you'll feel better...

L.Adamson

[drb930]

Originally Posted by L.Adamson

I suppose these tools are fine, but I actually really do like the fly cutter. I've done two complete panels with one. I do have my own techniques, which someone might be interested in.

First, for the centering hole, I'd use a unibit to one size smaller than 3/8", and then a standard 3/8" drill bit to finish the hole. Of course, this would all depend on the fly-cutter pilot shank size. This provides a tight starter hole with no slop.

Then, I'd spin the fly cutter through a few revolutions by hand, on the top side of the panel to score the circle.

Flip the panel over, and litterly "plunge" cut the holes using 450 rpm on the drill press and "NO" oil. Just pull the handle to plunge into the material for a few revolutions, then lift & plunge again. The circles will pop out in a perfect diameter, and can be finished off with a slight hand rubbing of grey scothbrite pads. One advantage that I find with fly-cutting, is a much less chance of distorting the flat surface, that can sometimes happen with die cutters.

edit- use particle board under tha panel, with the pilot hole drilled in particle board also. And clamp everything.
Leather gloves, if you'll feel better...

L.Adamson

Any information on where to get a good fly cutter?

[rzbill]

Never seen one. Not sure it exists Mine were from the DIY store. The center drill wobbled like mad so a bit of skill was required.

Yes, I fly cut my panel too. Careful and methodical and a good result can come, like Mr Adamson says. I had a set of tools called "Rotabroaches" that were very handy for doing the altimeter assymetric cutout and a few other spots because it has a central pilot.

A rotabroach add grabbed off the net

[Mike S]

Originally Posted by drb930

Any information on where to get a good fly cutter?

Originally Posted by rzbill

Never seen one. Not sure it exists

Exactly my thoughts.

[David Paule]

There aren't any. But the Malco HC-1 hole cutter is great! Amazon sells them and I'm sure other people do too.

You can read all about it here: http://www.vansairforce.com/communit...ad.php?t=91463



Dave

[Gerald Clabots]

Try doing a search under circile cutter.
General Tools 55 Heavy Duty Circle Cutter at Amazon.
I bought mine years ago at Sears. Works great, Just make sure your work is well secured before you start cutting
Gerry

[paul330]

Download the dwg, add your own cutouts and have it water-jet cut. I found a local engineering company that did it as a filler job for less than $100.

Beautiful results.........

[OLDSAM]

Where do you download the dwg? Is that as in an AutoCAD .dwg file?

[paul330]

Yes, although you can use a budget program - I used TurboCad.

Files are on the VANS site:

http://www.vansaircraft.com/public/downloads.htm