Rotary welding positioner build

[Tmate]

I combined an old Troyke rotary milling table with some drill press parts to make a variable speed welding positioner.

Spring loaded brass rod riding against the table provides the ground. It is insulated via nylon bolts and flat washers. Ground cable gets clamped to upright part of bracket. Three clamping shaft collars and some scrap steel bars make a super-sturdy adjustable hand rest. It uses an 8 amp. 12 volt DC power supply and a separate speed control. Future plans call for an adjustable torch mounting bracket and solenoid trigger control (see sketch).

 

[Shox Dr]

I like that.

 

[skotl]

Me too. But it looks worryingly clean…

 

[Tmate]

Finished the torch mounting apparatus. Bugo rack and pinion torch holder knob provides large up/down adjustment, while steel mounting bracket does the same for in/out movement. Tweco JT-2 torch holder provides fine adjustments up/down, in/out, and torch angle.

Next step is to mount a 12 volt dc plunger solenoid to operate the torch trigger.

 

[jazzyman2012]

I used to use a very similar machine many years ago. Think one of the problems was earthing the device to the mig welder, there were problems with the rotary table bearing arcing. Not sure if you hit the same problem?

 

[dan.taylor.1]

Can you not just set the machine to 4t and manually start the weld, and stop when necessary?

 

[Bobupndown]

What are you making to require such a contraption?

 

[wyn]

I like the way it looks like it's all set up in the living room of your house.

 

[Robotstar5]

We used a pair of sprung pickup blocks running on the back of the positioner table on one of our machines.

 

[Tmate]

I used to use a very similar machine many years ago. Think one of the problems was earthing the device to the mig welder, there were problems with the rotary table bearing arcing. Not sure if you hit the same problem?

While putting this setup together, I looked at how a number of others had tackled the earthing (grounding) problem, and came up with the above approach. This spring loaded brass rod approach is the only method I have tried, and it seems to work fine.

Can you not just set the machine to 4t and manually start the weld, and stop when necessary?

Yep!

What are you making to require such a contraption?

Just doin' it for fun.

I like the way it looks like it's all set up in the living room of your house.

Welding equipment, air compressor, plasma cutter, & computer are just inside basement door. CNC plasma table is just outside.

 

[Tmate]

Here are the results of several different motor/power supply combinations I have tried on my rotary table/welding positioner project:

Grainger 50 rpm gear motor & electric train transformer - not enough power to turn the rotary table.

Grainger 50 rpm gear motor & 4 amp dc power supply - stalled frequently, insufficient power even at a full 12 volts.

110v 60 watt 135 rpm ac gear motor, with reversing variable speed controller (cheap import) - adequate power, but could not be started at a desired rpm. Had to be at zero rpm to be started, making the use of a foot on/off switch impossible.

12 volt dc, 6 amp, 100 rpm, reversible gear motor (makermotor.com) with speed controller and Radio Shack 8 amp 12 v dc power supply - adequate power, stalled at less than 7 volts, ran fine from 7 - 13 volts. The table rpm range (given the gear reduction in the Troyke table) was 1 to 3.3 rpm.

12 volt dc 13 amp, 110 rpm, reversible gear motor with planetary gear reduction (makermotor.com) with speed controller and switching 30 amp 13.8 volt dc power supply - Seemingly perfect combination. Runs with sufficient torque from 3.6 to 13.4 volts (the max I give it). Table rpm range is .5 to 4.5 rpm. Planetary gears are a little noisy at higher rpm, but work great. This motor/power supply/speed controller combination cost approximately $235.00 in total.

Next step is to sell the other motors and power supplies, or think of another use for them?? This has been a fun, if impractical, project. I obviously could have bought a Chinese welding positioner for less, but where's the fun in that?

 

[Barking Mat]

Nice, had it running yet ?

 

[Tmate]

Nice, had it running yet ?

Once - then changed motor set-up. Haven't tried it yet with these electricals, but should be an improvement.

 

[stuvy]

Once - then changed motor set-up. Haven't tried it yet with these electricals, but should be an improvement.

View attachment 382559

Any pics of the start stop of the weld

 

[Tmate]

Any pics of the start stop of the weld

Piece got tossed. As I recall, the start/stop points overlapped a bit. Should do a few more soon and will post pics once I get the knack of it.

 

[stuvy]

Piece got tossed. As I recall, the start/stop points overlapped a bit. Should do a few more soon and will post pics once I get the knack of it.

I’m impressed mate