Rotary Jig for AC TIG tubing

[FASTdan]

My products involve a lot of tubular butt welds (see attached). I do the butt weld prior to welding to the flange for obvious reasons.

I am looking to build a rotary jig to allow me to complete the joint in a single run - this would save massive amounts of time and gas (pre/post flow!!) due to only one stop/start per joint (currently 3-4 depending on tube dia and design). Not to mention the welds would look much nicer!

Just looking for ideas/inspiration on a power source and control. Ideally 240v and speed controlled (guess I would need to mount the control on the torch). I've been trying to think of other tools/products that could be butchered to build such a jig, but I'm struggling for ideas....

Basically needs to be slow, but variable speed, 240v.....

 

[rtbcomp]

Get the motor and pedal from an electric sewing machine, you could gear the motor down or fiddle with the electronics to restrict the speed to a useful range.

I've made a turntable for blasting wheel rims from a rear hub and disc from a car.

 

[FASTdan]

Of course!! Genius - bloomin' obvious solution. Thankyou!

 

[scott0031]

I am assuming that you do know 'welding positioners' are a common piece of standard kit and sometimes at pretty good prices.

eBay worldwide search for welding positioners.

http://www.ebay.co.uk/sch/i.html?_s...=0&_nkw=welding+positioner&rt=nc&LH_PrefLoc=2
http://www.ebay.co.uk/sch/i.html?_s...=0&_nkw=welding+positioner&rt=nc&LH_PrefLoc=2
One there coming up in Poland called sherman. Light duty ideal for what you want, 300 quid.... is it seriously worth making one at that sort of money.



Kind regards,



Scott

 

[wheresmejumper]

How slow do those cheap hobby lathes go down to?

 

[hotrodder]

There's several home made examples kicking around the forum somewhere. Shox Dr and Wyn are two names that'll narrow the search down some, Shox had several 3 phase 630:1 gear reduction motors with matching VFDs for speed control that were ideal

Like the commercially available ones the examples are on the forum are heavier duty than you'll need if it's exclusively for smallish dia ally tube but that's a good thing... any rpm fluctuations, vibration etc will make one horrible* to use as for welding, especially TIG, we're talking very low rpm. If you weld at say 12" minute and we're talking say 2" dia tube then the weld is 6.28" long and would take ~31 secs. 1.5" dia and it'd take ~23.5s. Over 4" dia and you're into fractions of 1rpm

* I've got a vague recollection that Drains had use of a commercially made example that was pants, can't remember if it was speed fluctuations that made it horrible or if it didn't have the torque to cope with stuff well within it's published weight capacity. Might have been both or just that it couldn't be slowed down enough for TIG?

 

[rtbcomp]

These are some pics of my turntable



The hub and drum are from a Rover 100, the disc is from an MG, although the disc from the Rover would be fine.

The gearbox from a Belle cement mixer will give a 40:1 reduction.