I want to modify a Gas mig to run gas and gas less wire , with external +/- terminals so i can swap the polarity for gas / gas less.
Any advice and wiring information and advice on components on carrying out such a modification please ?.
Its a Migatronic MX 5000 i posted before but it got moved just like this time, if you can help please do im getting desperate now i want to get on with this job. .
I purchased a roll of gas less wire, , and stored it having procured a argon bottle and a co2 bottle.
I ran co2 for months but decided today after running out of wire to try the gas less wire to Finnish off a wing repair on my old austin devon project.
Result was the gasless wire in the gas migatronic was spattery and fierce a lot of heat i felt, it welded and cleaned up ok, but compared to with gas or if compared with the switchable sip migmate turbo 130 on gasless terminal the migatronic was Fierce and although it worked i think i will not bother running it on gasless wire anymore, in fact i think i am going to put a new gas pipe on my sip (the reason i went gassles). Your opinion may vary but despite gasless technically working , i thought it was not as good as with gas for the car wing repair, it might be better on heavier steel but even though the devon panels are not exactly thin /flimsey it still seemed gasless was a bit wild to my way of thinking./ ability.
Regarding your original question about swapping torch & return polarity for gasless on the MX5000:
It would basically involve powering off and unplugging, removing the covers, locating the power connections at the Eurotorch mounting block and the return cable, and swapping them. These will be heavy bolted connections to thick flexible cables. Originally the torch block would be positive, from the rectifier and the capacitor bank. The work return cable ( typically known as the "Earth" ) would be negative, from the inductor ( choke ). To be able to swap them, you may need to extend wires - use heavy welding or car battery/starter cable.
Ensure that the swap is done right where these two connections exit the machine, not further back inside the low voltage high-current circuit.
The machine has polarised electrolytic capacitors, and I believe that welding voltage is used for coarse control of the wirefeed motor speed, so you must not swap polarity at those points in the circuit.
[ Depending on how the torch trigger switch is wired, there may possibly be an issue with the trigger signal from the torch to the control PCB now being of the wrong polarity.]