# Welding Positioner



## aliva (Jul 1, 2022)

Not really a day project more like a couple of weeks.

This is my latest project, a welding positioner. I have a shaft and sprocket to weldup and I thought it would be a nice project. I checked the cost of a commercially available unit, but the prices are ridiculous. So why not attempt at building one.
This all started this past winter. It was along drawn out process, from designing the unit, finding parts order parts, make a control box because I could fine one the right size.
So I purchased a  10 amp 120VAC to 48 DC variable controller. Now design the rest. I had to come up with some sort of electrical schematic that would give me directional control, speed, foot control and why not add a tilt, not that it's really needed, but I had a linear actuator. Now find and order flange bearings that with fit a 1" piece of pipe. Now how am I going to drive this thing. I used a Via are compressor motor, but it turned to to be too fast, so a wiper motor I had laying around. Now figure chain size,, sprocket sizes, after some trial and error I settled on a 72 tooth drive sprocket and 12 tooth driver for # 35 chain. One of the most expensive parts was a sheet 4'x4' body metal for the control box, $90. The 3 jaw chuck was only $80 from Vevor.
The cross piece is 2x2x3/16 square tube. The ground mechanism it a piece of pipe with a solid piece of copper rod spring loaded to push up on the drive sprocket. A piece of braided copper was solder to the copper rod and connected to a piece of 3/16 copper plate welded to the frame, easy enough to attach my ground clamp. I wanted to keep the overall weight down so the frame is built using 1/2 electrical EMT brazed together.

All in all it was a much longer project than I thought it would be, because everything had to be made and the design was constantly changing.

I'm sure some of you will find some faults and improvements so your comments are welcome.
The total cost was around $275, Not bad compared to $1800 for a manufactured unit.
Here's a vid of it inaction


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## DavidR8 (Jul 1, 2022)

Oh well done!


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## brino (Jul 7, 2022)

Some great design elements.
Thanks for sharing this!

Brian


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## Just for fun (Jul 7, 2022)

Looks great,  thanks for sharing. 

Tim


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## keeena (Aug 30, 2022)

Nice build! That power tilt is unique

Does HF interfere with the electronics? And what is the RPM range? The wiper motor works fine at max voltage? Coming up with a mechanism that could do a wide range (say: 0.5 to 20 RPM) and not be affected by HF were my 2 biggest hesitations to making my own.


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## aliva (Aug 31, 2022)

I've used the positioner several times and have had no issues with the electronics in the controller, since the ground connection is on the rotating table directly, so the current flow takes the path of least resistence, it doesn't seem to affct the controller.The voltage controller is rated at 10 amps DC. I've welded at various current levels fron 45 -125 amps. The RPM is variable from approximetly 1-30. As the voltage changes so does the torque from the wiper motor, very little torque is required to spin the table at low RPM. The torque only has to over come the resistence that the ground connection spring applies to the table and the resistence from the flange bearings holding the table.The trickyiest part was to get the RPM correct for a smooth weld, took a few tries. I may add an adjustable support  so I can rest my arm while welding. Heres a pic of  inside the controll box, as you can see the the only electronics is the variable voltage box and a few DPDT switches and fan.


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## Tmate (Dec 7, 2022)

Very nice!


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