Automatic Wire Feed To Gun; Adjustment Of Pressure; Adjustment Of Tightness Of Reel Brake; Burn Back Time - Kemppi fastmig MF 29 Operation Instructions Manual

2.4. AUTOMATIC WIRE FEED TO GUN

Automatic wire feed makes change of wire reel more rapid. In reel change the pressure of feed
rolls need not to be released and filler wire goes automatically to correct wire line.
– Make sure that groove of feed roll matches the diameter of welding wire used.
– Release the wire end from reel and cut off the bent length. Be careful that the wire does not
spill from the reel to sides!
– Straighten about 20 cm of the wire and see that the end of it has no sharp edges (file off if
necessary). A sharp edge may damage the wire guide tube and contact tip of the welding
gun.
FastMig™ MF 29 wire feed unit:
– Draw a bit of loose wire from wire reel. Feed wire through back liner to feed rolls. Do not
release pressure of feed rolls!
– Press the gun switch and feed wire until wire goes through feed rolls to gun. See that
wire is in grooves of both feed roll pairs!
– Press still the gun switch until wire has come through contact tip.
Automatic feed may sometimes fail with thin wires (Fe, Fc, Ss: 0,6...0,8 mm, Al: 0,8...1,0 mm). In
that case you might have to open feed rolls and feed wire manually through feed rolls.

2.5. ADJUSTMENT OF PRESSURE

Adjust the pressure of feed rolls with the control screw (20) so that the wire is fed into the wire
guide tube evenly and allows a little braking when coming out from the contact tip without slipping
at the feed rolls.
Excessive pressure causes flattening of the filler wire and damage to the coating. It also
causes undue wear of the feed rolls as well as friction.

2.6. ADJUSTMENT OF TIGHTNESS OF REEL BRAKE

A
Adjust brake force as so big that the wire is not allowed to become too loose on the reel so that
it would spill from the reel when the rotation of the reel stops. Need for brake force is increased
with increase of wire feed speed.
Since the brake loads for its part the motor, you shouldn't keep it unnecessarily tight.

2.7. BURN BACK TIME

Electronics of feed unit controls stopping of welding automatically so that the wire end doesn't
melt fastened to the contact tip or the work piece. Automatics work regardless of the wire feed
speed. Can be adjusted also from power source SETUP-menu ('PoC').
© KEMPPI OY
Brake force is adjusted by screwing the
adjusting nut (B), tightening clockwise
B
direction.
FASTMIG™ MF 29 / 0603 – 9