Millermatic 135 wire feed issue

Make sure your contact tip is the correct size for your wire. Make sure your wire isn't rusty. New liner. New contact tip. New pinch rollers.

GWE

True enough for all. But first..make sure the drive motor is turning at the same rpm with no jerks or halts. Wiggle the speed pot as you watch. A magic marker mark on the powered roller is a good place to watch. Ive seen a couple that the speed pot was dirty/bad and it would do the shushu.

remove feed roller tension, and grab the wire that comes out the tip with pliers and holding the gun straight out..walk out some 15 or more feet. If you feel catching and grabbing..its either the liner or the spool tensioner. Now put an S curve in the hose and try it again. If it passed the first test, but now it grabs..its likely the liner. Remove the contact tip and try it again.If its now smooth, check the OD of your wire and the marking on your contact tip. (also check for rust on da wire of course. Adjust the roller pressure so it just bearly stops when the hose has a gentle curve and you trigger the wire against a block of wood. It should want to bend but will slip a little. If you put an s curve and it stops..tension a bit more. If the wire is a bit rusty or rough..take a Scotchbrite and wrap it around the wire before it goes into the liner, and hold it in place with a clothes pin (spring type). It it runs fine for a few feet, then starts hanging up..double check that the wire spool tensioner isnt tightening up. My lil Lincoln Weldpak 100 that I keep in the truck will do that in a heart beat as I dont have the correct washer under the wing nut.

Lastly..make sure that the power source you have it plugged into is capable of handling the power. Put a volt meter on the outlet and check it as someone runs a bead. I had the Lincoln start doing that at a friends house..bad wiring, long extension cord and the power was browning down to about 85 volts..didnt seem to effect the arc..but the feed motor was getting really flakey.

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

Don't know about the Millermatic, but my Lincoln SP125+ is very fussy about having clean wire. If there is even a hint of rust it will behave as you describe.

Once I figured that out, I now take the wire out of the machine and keep it in a ziplock that I've backfilled with argon or AG25 if the machine won't be used for a while. Haven't had a problem since.

Had one where the wire feed motor was messed up. It is a PM motor and the magnets surrounding the armature were glued to the inside of the motor case, and broke loose, leaving the magnets rubbing on the armature. Disassembled, cleaned, re-glued, worked okay then. Ken.