12 RC What could be wrong???

[hjm]

was doing a job today relighning a dump truck box bottom, with about 80 feet of weld to put down so i hooked up my 12RC, using self sheilded .45 wire,all flat position.
the trouble i was having was i would be welding along and it would kind of start jumping ,almost like the wire was not arcing then it would,kind of hard to explain but
almost like the wire speed was to fast for the volts, but no mater where i set it it did the same thing, but it was a bit better at the numbers i give below
these are the setting i was using,
DCEN
VOLTS-18.6
WFS-155-160 IN PER MIN
I checked the drive rolls and they didnt seem to be slipping, i have run gs fluxcore before and there was no problem, oh yes and i switched to DCEP just to try and it ran smooth, but then i switched back to finish.
i was trying everything.
any idea!

[badger76]

when u switched back? i suppose it done the same thing. has ur wire been out where moisture could get to it?

[hjm]

YA it did the same thing, and yes the wire has just been in the shop no oven for wire just a rod oven,

[hjm]

the wire i was using is E71-T11-H16

[gordfraser]

hows your tip?

[MMW]

Are you using knurled drive rolls? Regular drive rolls will slip & if you tighten it to tight it distorts the wire which can cause feeding problems. Try a new tip. Check the liner to make sure the wire moves freely. Are you keeping the gun mostly straight with no sharp bends? How long is your 14-pin cable? Miller recommends not going over a certain length. Check all your connections especially the 14-pin cable.

[Bob Miller]

Ground

Check your ground/work, make sure it's clean and making good contact.
The RC-12 will feed wire no matter what. If there is no voltage there (bad contact) it will seem like it's feeding wire to fast.
Good Luck,
Bob

[cruizer]

The innershield wire is not exact in diameter, doesn't matter who makes it, making it nessessary to use an over size tip.

It may seem to run better in DCEP. but you'll really have a lack of penatration, may look pretty, but........

[hjm]

for sure on the penatration,just switched to see if any difference.
I use knurled rolls, tip is new and i kept the lead as straight as possible,if it was the work lead not making good contact why would dcep seem to run better than dcen?
just curious
going to bring the whip in and check the liner!
it has only run about 3/4 of a 25lb spool of ss and about 50 feet of gs flux cored.
thanks everyone for the replys
really appreciate it

[crabber]

for sure on the penatration,just switched to see if any difference.
I use knurled rolls, tip is new and i kept the lead as straight as possible,if it was the work lead not making good contact why would dcep seem to run better than dcen?
just curious
going to bring the whip in and check the liner!
it has only run about 3/4 of a 25lb spool of ss and about 50 feet of gs flux cored.
thanks everyone for the replys
really appreciate it

Try over sized tip as Cruizer said. I like the c-clamp style work lead for any wirefeed.
EP would make the wire hot so it would sort of work.

-Ian