Making a hole in a metal control panel
One of my many projects is a Galaga 88 or Gaplus, sort of. I don’t have room for another UR game, but I could run a Gaplus pcb in my galaga cabinet using one of those double jamma adaptors from Mike’s arcade and a modified control panel. A bit pricey, but when you have finite space you do what you can.
I picked up a crappy Galaga panel from Mongo on KLOV and proceeded to strip it bare. When I mentioned my project to Lisa I was threatened with bodily harm if I messed up “Her” Galaga; so a spare panel was necessary in case I ever needed to switch back to the original. I sold off the joystick, cp harness and buttons to re-coupe most of my investment in the cp. Picked up a Gaplus pcb and repro galaga cpo from Troy Akey and was ready to go. Except that Gaplus requires a 4way vs Galaga’s 2way. What to do? Open up the joystick slot to accept the 4way movement. I’m not sure how Galaga will play using the 4way, but I’m going to give it a shot. To cut the hole I chose to use a Greenlee radio punch and die set. Why is it called a radio punch? I have no idea and couldn’t find any info about it. It’s a vintage tool from 1959 and I do know that it’s a very simple tool that allows you to make clean holes in metal. You pre drill the center point slightly larger than the bolt and then assemble the punch set around the metal. After a few turns on the bolt you have a nice clean hole. Here’s a visual:
Everything is in place it’s time to put the punch into the hole, or in this case, the slot. If your panel didn’t have a pre-existing hole, you’d need to drill one appox 1/16″ larger than the bolt diameter. I’m going to do my best to center this on the slot when I make the hole.
I mounted the punch so the cut would go down and away from the surface that the cpo would be applied to. Just in case any divot or lip was created by the cutting. A few turns with the wrench (socket wrench would be easier) and bingo! I think it took about 20 seconds to do.
The hole turned out just fine with no lip at all. Nice smooth, clean cut. I used a 1-1/16″ punch and wish I had used a 1-1/8″ instead. This would have eaten up all of the slot width, but I wanted to get this thing done and powder coated and didn’t have the 1-1/8″ punch on hand.
That’s it for now, I’ll post more after the panel returns from Pro-Tek with a nice new paint job!
Tags: Greenlee, hole, metal cp, punch, radio punch













September 15th, 2008 at 4:00 pm
It’s called a “radio” punch because the punches were originally used to punch round holes for the sockets for vacuum tubes in the metal chassis of the old radioes.
Bill
September 15th, 2008 at 11:31 pm
Learn something everyday. Good peice of tech history.
December 25th, 2009 at 3:24 pm
Update to this post as the topic came up on the KLOV forums and I thought I’d include some of the details…
You can use a 3/4″ Greenlee conduit punch, part no 72BB, for buttons. Someone also noted that Harbor Freight has a inexpensive set of knockout punches, item no 91201-5VGA, for $16. They also have a hydraulic version, item no 96718-1VGA, for $100 and for $29 you can get a 3″ knockout that will “likely” handle 3″ trackball openings. Good stuff.