Chassis Punch trivia

[kg]

About those punches, I still have a couple Argentine made ones from the glorious tube era (when I started, over 40 years ago).

wow, you're old.

[jrfrond]

Because we do mods and some custom building here, I am lucky enough to have lots of sizes, including the IEC punch (THAT one was pricey, but we retrofit a lot of older gear and has paid for itself many times over). However, I've never needed the D punch for AC cable strain reliefs and don't know if one even exists. I'm, guessing it does, but I've never looked for it.

BTW- Yes, good chassis punches are expensive, and you need to maintain them. I've rubbed them all down with TFE oil lube, and when punching, I apply a bit of cutting oil to the punch edge. You wanna keep these babies sharp. Rubbing oil INSIDE the die also helps with removing the slug.

[J M Fahey]

wow, you're old

You bet.
I started in February 1969, with fresh 16 Y.O.
Just do the math
If it reminds you of a *very* popular ball type Shure microphone, you are close enough.
Although I guess there are more than a few of us oldtimers here. :O

[tubeswell]

What do you mean by "1.2mm Ally"?
1.2mm aluminum sheet?

Yep

About those punches, I still have a couple Argentine made ones from the glorious tube era (when I started, over 40 years ago).
Now they are absolutely unavailable (and have been so for the last 30 years, since B/W tube TVs came out of fashion) *but* my friendly lathe man has offered me cloning any of them, in same or custom sizes , for a very reasonable price.
For me, it would be cheaper than importing Greenlees, maybe in US it's not worth it.
Of course, the round hole ones only.
He told me good steel is easy to work on, the required strength comes later, after heat treatment.
He suggested carrying them to a car parts carburizer/nitrurizer for surface strength and good edge sharpness retention, although ... "for aluminum sheet you can use *anything*"
I'll give it a try.

There is also the plasma arc technique for hardening the surface of metals (if you know someone with a vacuum plasma chamber). My brother was building them at Uni when he was working on his PhD in quantum physics. They use quite a bit of electricity to generate a plasma arc between two electrodes in a vacuum. The thing has to be kept really cold as well, so its an expensive device to operate as well as build. But I am reliably informed that it hardens the surface of metals incredibly well, and is very useful for finishing off bearings etc and other objects which are subject to constant wear.

[defaced]

A more practical(cheaper) method used today is lasers. The ability to precisely control the spot size, focus, energy input, resultant speed and lack of requirement for a vaccum/shielding gas has made lasers pretty popular for localized heat treating. I did some hot wire laser welding work with a company that had a diode laser system setup for hardening the ring edges on pistions. Though for a common punch, tool steel and hardening are cheap and have worked well so far.

[tubeswell]

Interesting. I must admit I was a bit bamboozled by the theory of it myself. My brother wrote up his initial experiments with plasma chambers in his master's thesis. Most of it was algebraic formulae, and I tried not to get too bogged down by it. But he did show me a couple of the plasma chambers he built in the university laboratory (with university funding) where he was doing his studies, and he sort of explained it to me in layperson's terms. Apparently you put the bit of metal you want to harden into the chamber (between the electrodes) and then activate the plasma field. IIRC, the process does something to the atomic tructure of the atoms in the surface layers of the metal, and makes the surface extremely hard. Don't ask me to explain it further than that. He was doing his PhD in applied physics/engineering with sponsorship from some firms in the metalurgical industry, but after 3 years his PhD supervisor left the university and he couldn't find another supervisor, so he had to put his PhD on hold. He has since emigrated to Oz and works for a computer software company peddling IT to local govt in Melbourne and Sydney. Shame - because the mad-science part of his career seemed far more interesting to me.

[J M Fahey]

He was doing his PhD in applied physics/engineering with sponsorship from some firms in the metalurgical industry, but after 3 years his PhD supervisor left the university and he couldn't find another supervisor, so he had to put his PhD on hold. He has since emigrated to Oz and works for a computer software company peddling IT to local govt in Melbourne and Sydney. Shame - because the mad-science part of his career seemed far more interesting to me.

Shame indeed.
We are concentrating our best brains on, literally, soft ware, nothing bad with that, but it can't be *all* we do, while China and similar just industrialized Countries are getting to make the hard ware, meaning every physical product you can sell.
If you go to WalMart you'll see the shelves filled with millions of U$ worth of things which you pay for.
Their manufacturing, transport, sales, etc. yes, does include use of software, but ... what percentage of the total goods value does that mean?
The most important problem, however, is that the software Industry provides (well paid for, no doubt) work for a few; while the physical parts and products making Industry provides work for Millions.
Work we have already lost in a great percentage.
Oh well.

[deci belle]

I just ruined a .050" steel chassis I didn't want to use by over-stepping my step-drill and made the 11/16" lamp hole a 3/4" lamp hole. I can fix it by welding in the punch-plug from one of the 3/4" tube holes and re-punching it with the proper chassis punch I just ebayed for $29. Shoulda had it to start with!

[Wittgenstein]

I just ruined a .050" steel chassis I didn't want to use by over-stepping my step-drill and made the 11/16" lamp hole a 3/4" lamp hole. I can fix it by welding in the punch-plug from one of the 3/4" tube holes and re-punching it with the proper chassis punch I just ebayed for $29. Shoulda had it to start with!

I have done the same before myself. I have taken to putting some scotch tape around the step bit right above the 11/16 mark. Luckily mine was on a scratch build, so I just used the hex nut on either side.

[KFTG]

Oohhh be very careful when punching through s/s. I would use plenty of lube and turn the wrench very slow. Those greenlee punches work good in their element, but going over that can lead to disaster. A Greenlee hole punch is comfortable with 1/8 in aluminum. S/S is soooo much harder, and if you break the bolt, or worse yet break the punch then that can get expensive. Lots of luck there.

[tedmich]

Tubeswell is PunchdrunK!

what happened to drilling it out and then making a lopsided square with a bastard file?? Or nibblers??

I broke the blade off mine after 2 "nibbles" of 304 SS...

still saving up for a CO2 laser...

[tubeswell]

I used punches on my last steel chassis and they worked fine. You just have to keep them lubed