Rectangular hole punch

[flintstone mop]

Does anyone know of an effecient way to cut rectangular holes in sheet metal for large rocker switches. SIZE: 1 1/2" X 3/4"

We have been sweating with a air tool with a grinding wheel.....hours and hours for 6 switches.
Greenlee makes very expensive ones starting at $400.00
Thanks

Fred

[W9GT]

Get one of those nibbler tools made by Adel?  Not sure of the mfr.  Also, I think Harbor Freight has one that you use with an electric drill and also an air nibbler tool.  All work FB.  Much better than hacking out holes.

73,  Jack, W9GT

[KF1Z]

Those Roto-Zip tools work good too.. (big azz dremel)

Then square the corners with a file...

[Pete, WA2CWA]

I've used the Adel Nibbler since the late 60's. Works great. Still using my original one.



http://aircraftspruce.com/catalog/topages/nibblingtool.php

[W9GT]

I've used the Adel Nibbler since the late 60's. Works great. Still using my original one.



http://aircraftspruce.com/catalog/topages/nibblingtool.php

Yup...That's it!  Had great results with mine as well over about the same time frame.  I thought about getting a replacement bit for it, however, the whole tool is pretty cheap.  I didn't know if they were still available.

73,  Jack, W9GT

[WA1GFZ]

I just used my Adel a few nights ago on my HPSDR Chassis converting the 12 VDC plug to a 115VAC interface.

[W1RKW]

for 1/8 inch aluminum I scribe the hole then use a reciprocating saw with a metal blade. Drill a few holes prior then insert the blade and start trimming. Then file to smooth the edges.  Anything thinner including sheet steel, the nibbler is the ticket.  For the big rig, I dumped the idea of using rectangular switches and went with toggle/lever switches. Drilling round holes was easier and faster to get the job done.

[w3jn]

Drill a hole in each of the 4 corners of where the square hole will be, then use a Dremel with a small saw blade attachment.  30 seconds per hole.

[WBear2GCR]

Friend with a milling machine a best bet too... 

But a whole bunch depends on if you are working with aluminum (easy) or steel (harder).

For steel the dremel cutoff wheels might be a good bet - the heavy duty ones, corners drilled first... although depending on the gauge the nibbler is ok too.

I used to have one of those nibbler tools - someone "borrowed" it back in the 70s... have not replaced it to date. Maybe I should. Not sure since I now have the milling machine, the router, the roto-zip, the dremel and some other devices...

               _-_-bear

[flintstone mop]

Thanks for replies.
I definitely remember the nibbler.
We were working with a steel panel similar to panels used for racks. It was nasty but it worked out with the air tool.
Fred

[Todd, KA1KAQ]

I used a nibbler years ago to modify a cabinet with fairly thin metal (aluminum). Worked great, so well that I nibbled a bit too much in one corner. Thickness of the material tends to be the determining factor in the use of any hand tool. Johnny's 'holes and small saw' approach seems sound and pretty speedy, too. Drill the holes well inside the corners, then smooth off with a file as mentioned.