CHASSIS HOLE CUTTING GONE WAY WRONG

[ViperDoc]

BURNISHING AT ITS *LESS THAN FINEST*:

[sluckey]

That's not bad. Some small drill bits, assorted files, and 2 hours of sweat will fix that right up.

[ViperDoc]

The cutter edge snapped right at the tip. I didn’t even hog into the chassis, I took it one bite at a time, then on the last push it broke and went buck wild. The underside of that cut trough is raised slightly. “Heavy duty” my GD foot. I think I’ll go the Greenlee route here in the future, that method looks awesome.

[sluckey]

Harbor Freight is known for cheap, not heavy duty.

[pompeiisneaks]

As the saying goes, for a product there are three measures of it's overall quality:

1 cost to build it
2 speed to create it
3. quality of finished product

You can always choose to optimize only 2 of those. the third always suffers

make it faster, but cheaper, quality goes down
make it faster, but better quality, the price goes up
etc

Or something like that. Harbor freight goes to lower all three
cheap, fast and low quality

~Phil

[Phil_S]

You will be able to work with that. It will take time, sweat, and patience. Think of it as the penalty levied by the court of injustice. Here's what I think I'd do.

If you can, without doing more damage on the other side, see if you can grind or file the hump on the other side flush with the chassis. Removing that material will ease removal of the plug. Then, take a relatively small drill bit and drill a series of holes near the outer diameter, but not touching it. Optional, cut with a jig saw using a metal blade. Use a round file to work your way to the edge of the hole. You'll probably want some ear protection from the sqweaking of the file. I might use some light weight cutting oil. Finish with a deburing tool if you have one, or use sandpaper. If the hole is too large when finished. you should be able to fashion a metal plate with the correct size hole and afix it to the chassis with some sort of epoxy or screws.

[ViperDoc]

Thanks, all. Just so long as the OD is not too hideous, I'll likely just saw the plate out, de-bur it and move forward. All I need is to float a can cap over this, so no biggie. I ordered a Greenlee punch kit, so I'll use that for the other holes. Thanks for that recommendation.

[ViperDoc]

THE FIX IS IN:



Thank you to whoever recommended the Greenlee knockout tool set, that's what I used to re-punch the derelict mess and the other two can cap holes.



These are pretty decent holes, good enough for me.

Three surprises I was not aware of:

1) The Greenlee tool "size" under-represents the actual hole size being made. For example, the "1-inch" tool actually makes a 1.3" hole because the "1-inch" rating correlates to the size of conduit you would use when using this for electrical purposes.

2) The "minimum pilot hole size" is listed as 7/8-inch for all but the 1/2 inch tool, but the bolt itself is only 5/8-inch in diameter. If you're accurate, you can tap the center to 5/8" and nail the intended hole location without worrying about cutter slippage.

3) I used a drill press and step bit to start and enlarge the center holes. This made for a lot of metal carnage that I thought I cleaned adequately. However, a small metal shaving found its way into one of my knockout cylinders and locked up my threads while trying to make one of the holes. I used an air can to blast it out and traced the threads with an awl to get the deeper splinters out. All is fine now. Just beware.

[sluckey]

Greenlee also makes a line of punches called "Radio Chassis" punches. These are actual size, ie, a 1" Radio Chassis" punch is really 1". They are pricey. Never seen a "set", just individual sizes.
3/4, 1, 1-1/4, 1-3/8, and 1-1/2 sizes will go a long way.

[ViperDoc]

VERY GOOD TO KNOW, thanks man!

[TonewolfAmps]

I noticed amplified parts / Tubesandmore / antique electronic / CE whatever they are calling themselves today carries what appear to be quality knockout punches in regular (not conduit) sizes. I'm lucky as my grandfather was an electrician/seabee and I inherited his tools some time ago so my greenlee punches are probably from the 50s or 60s and they still work like charm never even sharpened em.

IMG_20200422_213823703_HDR.jpg

[ViperDoc]

Nothing like a good set of tools, brother!