I just bought a used welder which is larger than my old one. The seller only sold the welder, not his cables. The cables on my old welder are fine, and are supposedly made for all welders. At least that is what I thought. For some reason the plug on the Ground Cable on this new welder is thicker than the Hot one, so the standard cable plugs fall right out. Yesterday I stopped at our local farm supply store. They carry a good selection of welding items, and they did have the thicker plug. I was just going to change it, when I discovered that I can not figure out how to remove the old plug. I dont want to break it, because I may want to use my old welder in the future again.
The cable end has a molded kind of material that is shaped like a piece of plastic pipe about 3/4" thick and 3" long. There is no set screw in it, no hole in the side of it, and it does not seem to be screwed on. Tapping on it does not seem to slide it back. How the heck do these things come off? I'm guessing there's a set screw under that molded "pipe" insulator, to take the wire out of the brass plug, but first I need to get that insulator off and I have no clue how.
Tweco connectors have a set screw, but some others are force fit over the brass center. The outer rubber cover can be pried off using 2 flat screwdrivers as prybars.
Factory cables often have press fit connectors. If you don't find a set screw, you will just have to cut the connector off. Try heat on the plastic to see if you can soften it enough to slide it back.
Some connectors are molded on after the metal portion is crimped. Can be a useful cost reduction for the cable mfgr. if the volume is high enough. PITA for the end-use to change/replace though.
Could you buy a "thicker" socket in addition to the new "thicker" plug and use the two of them to make a "plug adaptor" so you'd be able to easily use the Ground Cable on your old welder when and if you need to?
I might try a cutoff wheel on a die grinder to heavily score the shield, then gently use a utility knife to try to cut through the remainder hopefully without cutting through the insulation below.
Also, carefully check the larger socket. If it appears significantly worn, you may want to replace it with one which fits your ground cable. Actually, you may want to replace it rather than the plug anyway, that neatly bypasses the problem of removing the plug.
I like Tweco cable connectors. They are easy to use.
Thanks for all the help. It's too late for pictures. I pried and pounded and beat on the thing for close to two hours, until it was so far destroyed that I just took my angle grinder and cut the insulator shell off. I had figured I could use a piece of auto heater hose. But when I got this insulator off, I found the brass part was soldered on to the cable. At this point I just cut it off and threw it in the trash. I'd never be able to switch it on the cable to use the other welder. I'll just buy another screw on one to fit that welder, or maybe just make another cable entirely. If I had known it would be such a hassle, I might have just made another cable completely and not ruined that plug. I could use a longer cable anyhow, so I will likely buy more wire and make the longer one for the new welder and put the smaller end on for the older one. I tend to think someone glued the insulator onto the knurled brass piece because I just would not come off no matter how much I beat on it.
I like the new screw on one much better. One large 1/4" hex screw against the wire, and a small screw to hold on the insulator. One minute to install, and it was done...... For a $7 plug, that was just too much trouble, not to mention jabbing my hand with a screwdriver, and bleeding all over the place. Live and learn, and I learned this one the hard way....
I suspect that is intended to reduce the chances of accidentally interchanging the ground and the hot. Is this a fancier machine with switches to change the polarity at need? Or an AC machine, where it does not matter what polarity is used?
Did you bother to buy the plug, or did you leave it in the store? Examining the new plug might give you clues as to how the old one is fitted.
Well ... I've seen lots of high current connectors, and the possibilities are:
1) Wire soldered or crimped into connector, and the plastic sleeve molded on.
2) Wire soldered or crimped into connector, and the plastic sleeve screwed onto the connector body. Grip the pin, and turn the sleeve counter-clockwise (viewed from the cable end). (Check whether the sleeve has a smaller minimum diameter at the cable end than at the pin end. If otherwise, then it may unscrew from the pin end instead, so you rotate it the other way.
3) Wire soldered into connector with a two-part sleeve screwed around an increased diameter part of the pin.
4) (2) or (3) above -- but with the setscrew which you expect (which I think less likely for the kind of current which you need to carry.
Note that I have seen some connectors with covers like (3) above which were two-part in the metal, too. The pin is female threaded in the back, and there is a sleeve which slides on over the wire and which is then soldered in place. The sleeve has a matching male thread, so it is screwed into the pin after the soldering is complete, and then the two halves of the sleeve are screwed together over that. (Obviously, the cable end of the plastic sleeve has to be slid onto the wire before the pin is screwed in place -- and (depending on sizes) perhaps before the metal sleeve is soldered to the wire.
5) One of the many other possible ones.
If you need to keep the cable so it can go back into the old welder's connector as well, I would suggest that you buy the male connector to fit your new welder, a short (perhaps one foot) length of cable, and a female connector to fit the connector on your old cable, so you have adapted it to the new welder.
I note that you have cross-posted this, but I don't see signs of what I would have considered the best newsgroup for the purpose, SEJW (sci.engineering.joining.welding). They certainly have experience with the connectors used in welders.
I've not read that newsgroup, as I do not have (yet) a welder, though I have lots of experience with various styles of connectors, including some high-current ones.
Knurled suggests that it was either moulded in place around the completed connection, or that it was rammed into the plastic insulator when hot, allowing the knurling to lock it in place.
Once you got rid of the plastic insulator, you could have clamped the tip into a vise, and used a propane torch to heat the joint enough to release the cable from the connector pin.
I would have preferred a solder-on connector, or a crimp-on if I had the proper crimping tools. For a few months, you probably should take off the insulator and snug up the setscrew holding the wire into the connector pin body.
And if you had waited, among other things you could have seen my suggestion (just posted) for making a short (one foot) adaptor cable, so you could switch the cable between machines at need.
And actually -- I probably would have gone to a larger cable as well, so you can use greater length without having significant losses.
Understand you've already cut off the smaller plug. Faced a similar situation with both my leads and made "collets" to adapt between the two sizes. Turned to fit inside the larger female plug and drilled to fit the smaller male plug, split with hacksaw. I used brass.
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