Spool gun - Mightymig 130XT

[Kram]

Looks relatively easy, I'm not sure why its not standard, it'd be cheaper to make and only cost them maybe half hour more design to make it small and a cover

Changes needed are to extend the motor wires which are low voltage (12/24v?) and mount the spool and feed holder to the torch. And a cover. Lots of improvements are possible my plan:

Spool on torch
Front case connector for wires (swappable +/-, switch wire), removable mains plug goes in back of case
Connector on torch for gas hose, as I mostly use gasless.
Half width, lighter (0.6mm) aluminium case

Stupid question, how the hell do you remove the liner or gas hose from the torch switch?!? the brass bit turns, but neither pull out

Once its working, Ill make a much smaller feed/torch. I'm tempted to add a stepper motor for consistent speed / higher torque.

Im going to try aluminium soon after this is done, and thought it'd be cheaper than a new liner. Plus I dont like wasting the last two meters on a spool..

 

[Kram]

Ive done some test welds, feed is much better. Looks like this now, but not finished. Need to get some longer bolts to hold it together, insulate the spool and motor.

This is using the original parts, quite a bit of plastic removed, and housed in a square drainpipe off cut.

 

[mike 109444]

Nice job so far. Have been tinkering making up a spool gun but not yet finished (time...)
If yo have not already removed the gas and liner the should be held in by the push fit type fitting. You need to push the collar around the pipe and at the same time pus the pipe as though you are trying to push it in, then while still pushing the collar, pull the pipe and it should come out. Hope that makes sense !
If you can turn the swan neck through 90degrees then put a length of 38 or 45 ? dia drain/waste pipe over motor yo will then have a handle to which you can mount a trigger. Again hope it makes sense

 

[mike 109444]

Some pics that might give you some ideals

 

[carbon]

I use one for mig welding aluminium, very similar to the one mike posted a picture of with the red handle. I know yours is not finished yet but one thing I would suggest is add a cover to the spool as its surprising how much crap can get stuck on the exposed wire causing feeding issues

 

[Kram]

I think I prefer mine to the T gun shape. The spool ends a couple inches before my elbow so cant imagine it being in the way. This motor has quite a large gearbox so motor in handle wouldnt work.

No luck with the push fittings, the hose seems stuck in the collet part which can be pushed in - but hose still doesn't come out.

Got grinder out today, had some new 0.8mm discs to try, chopped the case a bit. its now about 2/3rds of the original width.

Its still **Language**ing heavy tho.

 

[Jim Davey]

You push the collar down towards the valve block to release the liner.

 

[mike 109444]

You might want to put something over the motor as the terminals are at the end of it (24v) plus you would not want to break them off.
Just how small are you hoping to get this unit !!!
There is a pocket mig......

 

[mike 109444]

Ref the "push fitting" they are designed to bite into the pipe to stop it pulling out. The more you pull the more they bite in, hence the "push collar down then push pipe as though pushing in, then with collar still held down gently pull on pipe. Could be it's bit in so well that it's not releasing its grip.

 

[Kram]

Would like to know if this welder will work with the +/- welding cables swapped. Ive been using gasless with it standard, perhaps Ill get better results (Im a beginner, struggle to get correct settings often). Ive not tried any proper welds yet only a quick test.

The torch switch gets power from the welding cable to turn it on - so will it work. I notice the negative cable is crimped to a solid steel cable which goes to the transformer. The Positive is a fork crimp, so easily unbolted. Not really designed to be swapped. Plan to mount some high current connectors on the front panel so they can be unplugged and swapped over. Not decided if I will buy 8mm bullet type connectors or just use some 10mm copper rod in a copper hole.

Also want the mains power out the back (away from the grinding/weld splatter!) and to be removable. Whats best? 13A IEC socket, or perhaps BS 3 pin plug on a very short lead so wont get damaged so easily.

Going to look for a manual and think about how to add stepper control for next torch Ill prob have it in the case but that means a 4/6 core wire going to torch. I'd be nice to have feed adjustable on the torch.

 

[Kram]

have not done much, got some more good ali welds before the bottle ran out :/

Making the new spoolgun. Recieved one of these stepper motors http://www.ebay.co.uk/itm/161648336470/ waiting for stepper controller from china http://www.ebay.co.uk/itm/141347594586/ controller takes 5v pulse, 200 pulses per RPM. This will give exact wire speed.

Rollers I have some 25mm ali rod, should make the torch quite small.

 

[Jim Davey]

You are going to make your drive rollers from aluminium?