Rotab Slip Ring For Welding

[HAP]

I bought a cheap HF 8" RT a few years ago with the intentions of using it for circular welds. It just sat around the shop getting rusty. So I decided to add a cheap CODCO 8" chuck to make holding things easier. There was always the issue of grounding... So, after checking out a few good examples from other members, I came up with a version that works well for me.
I bought a cheap $12.00 12" skillet which was much cheaper than aluminum stock of the demensions that I wanted. Cut out a ring to make the interface for the copper contact, attached with flush screws and milled the surface. I used a few copper pipe fittings for my contact and a really stiff compression spring. The nice thing is I can just replace the 7/8" copper cap if it ever wears down. I just attach my grounding clamp to the pig tail and weld away. I remove the crank handle and attach my 90 degree Dewalt drill with a router speed controller and a foot switch. As for the dual current path though the spring, I don't see it being a problem as there are no roller bearings to arc. The worm drive is not critical and has worked fine so-far. A fun project for the day. BTW: I had to drill through the chuck and tap holes in the RT for easy mounting.

Best regards,
HAP

[randyc]

I'm sure that there are reasons why that is a bad idea but I sure like it, LOL ! I have one of those cheap rotary tables that rarely gets used (and an eight inch four-jaw that gets used even less).

That is a good fix to a problem that always bugs me, especially when welding small diameters. Thanks for the idea and the good photo documentation !

Cheers,
Randy C

P.S. How about a fairly large diameter (but thin) copper spatter-shield sandwiched between the chuck and the rotary table ?

P.P.S. Beryllium copper or phosphor bronze coil spring ?

[macona]

Thats ought to do it. Only thing I would add is insulators to the base of the rotary table to make sure current does not flow through the rotary table itself. If the table is sitting on a grounded metal table current will still pass through the rotary table in places you do not want.

[HAP]

Macona, thanks for the input, that is a good idea. I will make that adition. I really enjoy posting my projects here as there is always great suggestions on how to improve a design.
HAP

[AiR_GuNNeR]

Slick idea using the copper cap. I like it!

[gda]

The best part of the post is getting the aluminum from a pan!

[vpt]

Nice! I am sure it will work fine. Insulating the grounded stud from the base of the table would eliminate the possibility of the current gounding threw the bearings or gears. Unless like mentioned the table the rotary is on is grounded.