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mike j
4th Aug 2007, 10:09 PM
Can a welder that has two settings 3.5 and 2.5 that is rod sizes for an arc welder be fitted with an adjustment knob to give it infinite adjustment that is from 3.5 down.

The reason is I am welding 3 mm box and am burning holes too much. Boc have a similar welder that can be adjusted down I was wondering if I could do this to my welder or get someone to do it for me.

thanks

Mike

echnidna
4th Aug 2007, 10:33 PM
Probably not.

Sounds like yours is a stepped transformer with 2 output terminals.

Adjustable welders are usually sliding choke where the core section is withdrawn from the coils to reduce the current.

China
4th Aug 2007, 10:37 PM
If your welder is acurate you should be able to weld 3mm on 2.5 without bowing holes, I'm not trying to be rude but you may you need a bit more practise on some scrap

Grahame Collins
4th Aug 2007, 10:43 PM
Mike, Welcome to the forum
The quick answer is no.

It is possible but not economically viable. With the money it would cost you could buy the welder with infinite adjustment.

I feel that it might be your technique rather than the welder.
Instead try this. Assuming you are using 2.5mm diam electrodes, keep your arc short as a long arc causes heat that makes the holes. A good arc length is equal to electrode wire diameter.

If that does not work,run the welder on a long extension lead.That should drop the input current and therefore the output current will be less.

Run the lead out and don't coil it for obvious reasons.
It should work.

Grahame

GraemeL
16th Aug 2007, 07:21 PM
To: Grahame Collins:
If a long extension lead will effect a reduction in input and output current, could not the same result be achieved by the introduction of some form of resistor added to the normal input lead?
:?
GL

Wood Butcher
16th Aug 2007, 07:27 PM
Theoretically yes, but then you could not change it back easily. It is easy to unplug an extension lead then remove a soldered resistor.

faex
16th Aug 2007, 08:04 PM
meh just weld slower or faster on 2.5 :2tsup:
dodgy solutions are the best

Ashore
16th Aug 2007, 08:28 PM
Mike disregard all advice given above , this is the perfect excuse to buy a bigger better welder Mig or Inverter, as big as the budget allows, but if the coffers are bear then disregard this post and follow the advice from above , but a new mig would be nice:rolleyes:

Stringy
16th Aug 2007, 09:09 PM
Mike,

I would not run a long extension lead, yes it will reduce current to the welder but will also overheat and stuff the extension lead. This is the primary side (240V) and should not be played with.

A just as dodgy solution:- is to coil your handpiece cable around an iron bar (build a magnet), the more coils the less amps at the handpiece, you can adjust quite accurately with this method. one problem will be that you will not have a very long handpiece lead to play with:doh: . Have had to do this when running 2.5 electrodes off a Lincoln DC600 Machine as they will not turn down far enough. Yes this also stuffs the cable (you would have to do a hellava lot of welding) but it is on the secondary side and should not kill you if it turns to doggy doo. Don't do this in the workplace :(( as it will be followed by a kick up the ????!

Obviously technique and fitup of your job are issues as well. One technique that may help is to set your job up in a semi vertical down position about 45degrees and weld down hill, too steep and the slag will tend to engulf the weld pool, especially as a beginner, this works for stick and mig with thin material.

Another method is to place a copper backing strip (copper flat bar) behind the joint to be welded, the copper draws heat away quickly and unless overheated will not stick to the weld.

Practice Practice and good luck