Pro 90 wire drive sliping off

[Harry Bloomfield]

The drive is via a directly driven wheel with two slots, one for each wire size, on top of which there is a bearing to act as an idler wheel. The wire is trapped between these two wheels and driven by them.

The idler wheel is kept in contact via an adjustable tension spring, all mounted on a plastic bracket. All worked fine when I bought it, but now the give in the plastic is allowing the idler wheel is slip off the wire and to one side.

I start welding, the wire comes out, then there is a click as the wheel slips off. I am maybe using too much tension on the wheel, but the wire is simply not gripped and driven if I don't. I'm using the wire which doesn't need a separate gas.

 

[octo0072000]

best to put up some pictures clarkes are normally not that bad so something must be off

 

[rtbcomp]

Have you just started using gasless wire? Is the mounting for the idler cracked?

 

[Harry Bloomfield]

Have you just started using gasless wire? Is the mounting for the idler cracked?

Well the has been in a couple of years and mostly unused. No the mounting all looks fine, just the arm appearing to bend. The idler is is quite narrow, so the arm doesn't need to bend far, for the idler to slip off.

I have had it 20+ years and only use it rarely, which was why I bought the gasless. I prefer stick welding if it can be used.

 

[Cobbler]

Is the liner shot, if it's one of the plastic ones, the wire might not be sliding easily, putting too much pressure on the drive mechanism. Drop the tension off & pull the wire from the torch end & see if it moves easily. A steel liner is cheap & makes a big difference.

As you have had the welder 20 years I would guess you know this already, if so I apologise.

Cobbler

 

[rtbcomp]

Have you changed the tip? IIRC gasless wire is 0.9mm which may jam in a 0.8mm tip, try a 1mm tip.

 

[Harry Bloomfield]

Thanks for the replies, but it seems I stupidly shot myself in the foot....

I was needlessly over tightening the idle pressure adjuster. Easing it off still drives the wire, but without the idler slipping sideways off the wire.

 

[rtbcomp]

Thanks for letting us know.

The correct way to set the tension is so that rollers slip if the wire is stopped from exiting the tip. The idea is that they slip rather than cause a bird's nest if the wire gets obstructed.

 

[Robotstar5]

The correct way to set the tension is so that rollers slip if the wire is stopped from exiting the tip. The idea is that they slip rather than cause a bird's nest if the wire gets obstructed.

Pinch the wire coming out of the tip with your fingers and the wire should slip in the rollers.