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Simple TIG positioner idea

Posted: Sat Nov 18, 2017 11:44 am
by bruce991
So I make these 16 inch diameter rotating turn tables on a lazy susan ball bearing for motorcycles. Just wondering if I wanted to try using as a positioner would I find that I am more likely to arc across the balls in the bearing as it will be the path to the work table for the positive current? Hoping to have stinger in a bracket fixed, using one hand to rotate a round piece the other with filler rod. Hate to just melt a hundred small balls in the bearing LOL. I had considered adding a copper wiper to the underside that would be in constant contact with my work table.

Re: Simple TIG positioner idea

Posted: Sat Nov 18, 2017 3:59 pm
by mcostello
Could You preload a counter clockwise rotation before starting?

Re: Simple TIG positioner idea

Posted: Sat Nov 18, 2017 4:31 pm
by LtBadd
Yes, you will need to keep the bearings out of the ground path.

Re: Simple TIG positioner idea

Posted: Sat Nov 18, 2017 6:46 pm
by MFleet
I've looked into the Lenco rotary grounds or just a wrap or two of bare copper wire around a centered shaft to avoid the issue.

I found this video from Terry and I think his wheel design would suit most of my needs. I watched a couple of his other videos to get the full details of it. In fact, most all of his videos are good.

https://www.youtube.com/watch?v=FjMWWNe2ndU

Re: Simple TIG positioner idea

Posted: Sat Nov 18, 2017 8:48 pm
by Farmwelding
LtBadd wrote:Yes, you will need to keep the bearings out of the ground path.
Yeah its amazing how quickly people need to replace bearings in farm equipment when the ground on the ends of the shaft...

Re: Simple TIG positioner idea

Posted: Mon Nov 20, 2017 2:45 am
by Arno
If you can extend a shaft down the center you could create a similar contact 'clamp' as Adam Booth did on his rotary welding table to avoid going through the bearing(s):

https://www.youtube.com/watch?v=yNTzn4npjxY

Around 19 minutes in... He puts the copper clamp on an insulated layer away from the metal of the table base so the only path for the ground is through the contacts and the center shaft, not the table base and bearings.

Edit: or of course use Jody's idea of using an old braided welding lead stripped of it's insulation and wrap that would a shaft so it provides the contact and can slide/rotate as you use the positioner.

Bye, Arno.

Re: Simple TIG positioner idea

Posted: Sun Dec 17, 2017 5:42 pm
by lrossini
Hi Arno

Sorry to write in this thread. I was trying to contact you because i’ve see you own a Oerlikon CTIG 1500 acdc. Are you happy with this machine? I’m about to but the same.

Thanks and best regards.