wire feed mechanisms

Date 05-31-2002 23:00

I have a craftsman 75 amp wire welder. I have never seen high quality wire welder feeder parts but have a question. In the higher end mig welders are the wire drives actually strong enough to bunch up the wire at the drive roll if the wire is stopped at the gun? My manual mentions setting the drive roller pressure so it slips if the wire is blocked at the tip. The wire slips even when the pressure is maxed out. The reason I ask is I notice the wire speed is often erratic. This makes it difficult to maintain an arc. Could the drive roller be worn out? I realize the best solution is a better welder, but I'd like to get what I can out of this one. This seems to be at its worst when running .023 wire. Yes ,I am switching the drive roll for different wire sizes.

By welder_guy2001 (***)

Date 06-01-2002 17:59

sounds interesting that your feeder is having problems already. you haven't had your welder long enough to wear out a drive roll...i remember when you first got it, and 2 or 3 months isn't long enough.

yes, the wire drives are strong enough to birdnest the wire when it's stopped at the tip in the higher budget welders. but like you said, you're supposed to set the pressure so it slips a little bit.

erratic wire speed could mean the friction nut on the spool reel is too tight. that's that little nut or bolt in the middle of the spool stem that you tighten or loosen according to what size wire spool you have. all that adjustment is supposed to do is keep the spool from unraveling after you've stopped welding. it keeps the tension between the spool and the drive rolls. if this adjustment is too tight the drive rolls will have a hard time feeding the wire, even if the drive roll tension IS maxed out. i usually test out the friction nut tension by pulling the trigger on the gun to feed the wire and then stop...watch the spool...if it keeps rolling, it's too loose. adjust it tighter till it stops rolling on its own.

another problem could be a dirty contact tip. not dirty on the outside, but on the inside...sometimes the wire arcs on the inside of the tip and causes lumps of steel to fuse to the inside.

and probably the last thing i'd check is the tube liner...take it all apart as far as you can and blow some compressed air down inside the liner. dust, dirt, and all kinds of stuff can get inside there and cause problems.

oh, and while you're welding, try to keep the lead as straight as possible to avoid kinking the lining. the less turns the wire has to go around, the easier it will be to feed it.

By Niekie3 (***)

Date 06-01-2002 18:11

Just another thought:

If you are using solid wire, the drive rolls generally have a serrated "V" groove. When using cored wire, the rolls generally have a "U" groove. Are you using the correct rollers for the correct wire?

Regards
Niekie

By awill4wd (**)

Date 06-02-2002 02:10

Another thing to check for if your wire drive speed is erratic, is the tension on the roll of wire where it is loaded on the machine.
My Esab Mig had similar problems in erratic speed but was traced to too much tension on the spool itself. As a rule of thumb, when you let go of the trigger, the spool should back off just under 1/4 of a turn.
If it's too tight, your wire feed is pulling against the tension of your spool and that's where you can get problems.
Regards Andrew.

By bzzzzzzzzzz (**)

Date 06-02-2002 13:16

It was puchased used. The welder is about 7 or 8 years old. When I first tried changing spools the drive roller was set for .024 and it had the .030 wire in it. I 'll try messing with the spool tension and see what happens. Thanks for the input.