One of the features of our new low cost  universal motor mount I am working on is there are four tubes that need ball joint adapters tig welded to the ends. Eight joints per motor mount. This is easy to do for a skilled tig welder but it is like riding a unicycle while juggling for me. I can get a functional joint but it is far from cosmetic. I have to stop...weld about 30 degrees.... stop.... rotate the tube 30 degrees and do another 30 degrees.

There must be another way so I am building a robo welder just for this job. I'll offer it as a service because it only takes a few minutes for each joint.

Pololu $22 gear motor has a 1000:1 gear reduction so it is slowly rotating the the tube at a constant rate. You just need to come up with the correct distance for the tungsten and the right welding current and gas flow. The rest is automatic with my Lincoln 175 tig I bought at Sun N Fun on sale.


The rollers that turns the tube are plastic as you don't won't 80 amps flowing through the gear motor. There would be a spectacular fire with a pool of liquid metal :)


The copper colored parts are just that and they necessarily ground the 4130 tube. Copper does not weld to steel.

Paul Lamar