Zipcut: Worth fixing or screwed?

[yellowfin]

Suppose for a minute I have a transformer based Miller plasma cutter, a Zipcut, bought it used and it's like mid-80's manufacture date. I was thinking being a Miller and transformer based it should be rock solid and impossible to fail, right? I just finally got it into my garage and it powers up once but then not the second time or thereafter. Obviously way the heck out of warranty. MAYBE it's the power cord gone wrong as there is a bit of slop at the end. Looks like it was replaced given that the plastic is new and the brass prongs are way newer looking than the original would be. What's the cost, generally, at getting something like this looked at and possibly fixed, given that transformer machines are supposed to be simple and made of stuff easy to swap out?

[wrench3047]

In Tn about $75-100 an hour, 1 hr min, plus parts. Its not terrible if you consider cost of new machine, about the same as mechanic shop.

[wb4rt]

Open it up and use a multimeter to do basic troubleshooting. It is easy enough to verify power to the switch. If no power there you can fix yourself. Then just move forward and test until you get past your comfort level. Likely you can resolve or at least identify the problem.

After that, report your results here for more detailed troubleshooting help.

Good luck!

[Virgil5]

"it powers up once but then not the second time or thereafter. "

As I recall from having suffered a ZipCut way back when, the ITW frustration machine is equipped with a safety built into the gun. The ceramic tip contains a Metal strip that shorts across the 2 brass lugs on the gun. The frustration machine will not trigger if that circuit is open.
I have begged the Divine Power to wipe all memory of that contraption from my mind, but I still remember those damn ceramic cups. Fact is I can probably go to a spot high up on the shop wall and find a small box containing gun components for the contraption.

There may also be an air pressure sensor of some sort preventing the contraption from coming on.
The circuitry is simple, and the miserable contraption can be forced to work with a couple jumpers. It can even cut metal up to 1/4" aluminum and multiple layers of metal, if it don't self disassemble.

[yellowfin]

"it powers up once but then not the second time or thereafter. "

As I recall from having suffered a ZipCut way back when, the ITW frustration machine is equipped with a safety built into the gun. The ceramic tip contains a Metal strip that shorts across the 2 brass lugs on the gun. The frustration machine will not trigger if that circuit is open.
I have begged the Divine Power to wipe all memory of that contraption from my mind, but I still remember those damn ceramic cups. Fact is I can probably go to a spot high up on the shop wall and find a small box containing gun components for the contraption.

There may also be an air pressure sensor of some sort preventing the contraption from coming on.
The circuitry is simple, and the miserable contraption can be forced to work with a couple jumpers. It can even cut metal up to 1/4" aluminum and multiple layers of metal, if it don't self disassemble.

Hmm, so replacing the ceramic cup could help. Tell ya what, maybe i could help you fully recover from the experience by buying that box of parts from you if it contains a cup?

[Virgil5]

You're forcing a brain cramp on me with that ferhoodled contraption.

There are 2 or 3 parts to the cup assembly, one is a ss wire cage, one is the ceramic cup and the 3rd is a plastic saddle shaped device. As I recall the brass safety shorting link is in the plastic saddle.

I cant remember if the contraption uses 24 volts to the trigger or high voltage.
Put a clip jumper across the 2 brass studs sticking out the sides of the gun and see if it triggers.

Keep your hands well clear of that damn nozzle. It WILL hurt you with the pilot arc voltage.

[yellowfin]

Aha, I observe one problem: I see a groove in the plastic saddle where the brass piece would be--and it isn't. So I should put a strip of brass or copper there to replace the one that apparently dropped out somewhere and/or get a new one.

[Virgil5]

Relax, they look that way. Gently scrape the stirrup portion where the studs stick out of the gun and you should see brass in the saddle.

So far I found 2 saddle assemblys with ceramics and 1 wire cage. I also found 1 new electrode.
I can't look any more till my Shrink clears me for Depression.

CRAP, now I'm thinking I might not have run the damn book for that ITW contraption thru the shredder and incinerated the shreds.

MORE DEPRESSION

[Virgil5]

Like this

[yellowfin]

An update: got a new ceramic cup with saddle in and it definitely had the brass strip where the old one didn't. Also had my electrician friend put a new cord on, where it looks like the old one had indeed sheared off inside. It powers on now, will test tomorrow or Friday and see where we're at. Definitely want to buy those parts from ya Virgil.

[yellowfin]

Further update: it runs now, but WOW is it forceful. I need to adjust it a bit and/or just learn to be faster because it's blasting through stuff and leaving nasty gouges instead of nice, neat thin cuts. Got plenty of power that's for sure.

[Virgil5]

The only adjustment is air pressure, and you won't gain much from dialing that back.

You need to establish cut and move as fast as you can.

Worn electrode will deliver a wide kerf eventually producing a 45° cut

Book says it was produced in 1984 by ITW
can't really expect much from an ITW product, they designed to fail.