New to me positioner

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I have some bigger work for my little "200" lb positioner.  I needed to weld 134 3/8" pipe couplings to some plate.  I think its boiler plate, but not sure.  Its A588.  7/8" thick, about 5" wide and 42" long.  Weighs 45 lbs.  I can't show you the real thing because I asked my customer and he said no.  So  I have a mock up plate that is bigger than the ones I need to weld by a few pounds and a foot in length.  I needed to know if this machine would rotate that much weight off center and it does no problem.  I bought the machine off Ebone for just over 5 hundred bucks plus a few more hundred for freight.  It came from kalifornia and weighs 400 lbs.I did this job last time on my little atlas, but it would trash it in no time.  SO after picking it up at the freight terminal, I plugged it in.  No workie.  It needed a piece of key stock and fill the transmission.  Its variable drive, 0 to 5 rpm in either direction.  for a transmission, it has a belt drive pump and motor.  A little crank changes the speed and direction of the table.  It also has an electric switch for forward and reverse.    If its in high speed, when it turn it on the lights flicker.  The things got balls.  It will pick ME up and spin me around.Right now it has no foot control.  When it does it will only be on/off because it needs all its power to run the transmission.  It had no sign of a ground, so I put my own on.  I tested it running pulsed spray really hot.  The ground didn't even get warm. It seems to work fine.  I stole this idea from some one on this web site.  I don't remember who or I would give credit.  SO here are a few pics.First the one on the left is an atlas 200 lb capacity (weighs 40 lbs) I bought new a couple of years ago.  I have used it a lot.  Its paid for its self over and over.  The one on the right is a Worthington welding positioner 100 lb capacity (weighs 400 lbs).  You can see the ground I added.These are the controls. The switch is forward and reverse.  The little crank to the right is the speed control.  Crank it one way and it goes faster until you reach about 5+ Rpm.   Go the other way and it slows to a stop, then reverses the direction and speeds up to 5+ Rpm.The electric motor runs full speed all the time.This is the first TIG weld I did on it.  It took a couple of tries to get the speed right.  I have no chuck, so I clamped the vice out of my drill press and stuck that T piece in the vice. welded the pipe to it for something to do.Here is a close up, this IS a welding site after all. Attached ImagesReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Dumb question:Grounded like that is not the weld current going through spindle bearing?A butterfly without wings, is just an ugly bug
Reply:OK, now that you have seen it, Here is what I have to do.  The plates are a little shorter.  BUT I needed the balls to spin this around so I can stand in front of it and weld on these 3/8" couplers.  I will be doing quite a few and make some good $s because I can knock em out in a hurry.  Last job I had to weld on a total of 134 couplings on 36 bars.  The positioner runs at about 3 RPM, so the actual weld takes 20 seconds.  Loading and unloading the machine takes longer, but I had it down pretty good.Just a "dummy" bar, If I show you the real thing, I will have to kill you.  It will spin it around including start from the position its in now.  To do the job, I will clamp the positioner to the forks and raise it up with the forklift.This coupling is a 1/2".  The real job gets 3/8" couplings so they are smaller yet.Pic of ground from back side.Thanks for lookingReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by Magnetic MechanicDumb question:Grounded like that is not the weld current going through spindle bearing?
Reply:Actually David, I think you need to modify your ground strap a bit.  To be sure the bearing is always completely isolated from any weld current the strap should be insulated rather than attached directly to the base.  I doubt it will happen, but should the resistance rise between the braded strap and the spindle the current could go through the bearings.  Ok, maybe I'm being nitpicky, but I thought I'd point it out.BTW - I used almost exactly the same ground on the rotary positioner I was buiding.  I simply took an old 2' length of 2-0 copper welding cable and stripped about 8" of the insulation off.  My spindle was horizontal, so I looped the cable around it and clamped it back to itself.  The weight of the ground lead applies suitable pressure to the spindle, and it's all insulated from the base of the machine.
Reply:Aaaah sooo ground strap. Could I suggest.?Bolt a jig to the faceplate to cut load, unload. centering time.A butterfly without wings, is just an ugly bug
Reply:Why didn't you just weld around the coupling , instead of getting the postitioner ,setting it all up ...
Reply:my guess is time, start/stops, consistincy nice positioner david u going to be sitting on a ladder to do this or what?looks like you do get the fun jobs250DXMM251MM175225G plus 251D-1
Reply:Originally Posted by Magnetic MechanicAaaah sooo ground strap. Could I suggest.?Bolt a jig to the faceplate to cut load, unload. centering time.
Reply:Originally Posted by BikespotWhy didn't you just weld around the coupling , instead of getting the postitioner ,setting it all up ...
Reply:To all of you.  I looked and looked for any sign of a ground for that machine.  I looked on the internet for another one like it to see where the ground was.   It sez "Welding positioner" right on the name plate.  You woulda thunk it came with a place to hook up a ground.  I think that machine is as old as me.  (1960)David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Nice looking weld Zap,...                            I mean David.
Reply:Cool Tool, David!!I want to see a pic of the positioner at working altitude with you on the ladder!!Rex
Reply:Originally Posted by rode2rouenCool Tool, David!!I want to see a pic of the positioner at working altitude with you on the ladder!!Rex