The ESAB Rebel EMP 215ic ships with a Tweco Fusion 180 gun, and its most-reported feed complaint is specific: solid .035 wire slipping even with the tensioner cranked. That one usually isn't tension at all — it's the wire climbing out of the drive-roll groove. Below is that fix plus ESAB's own manual remedies and the aluminum setup the manual calls for, each with the Tweco-style part for this gun.
Solid .035 wire slips and you've bottomed out the drive-roll tensioner trying to stop it. Watch the wire at the roll: if it climbs out of the groove and rides on the smooth shoulder of the wheel, the drive-roll shaft has too much side-to-side play.
Owners traced this to excessive endplay in the drive-roll shaft. Seat the wire firmly in the groove, take up the shaft endplay so the roll can't wander, and confirm the grooved (not the smooth) side of the roll faces the wire. Cranking tension to compensate just deforms the wire — fix the alignment instead.
Wire advances poorly or inconsistently with no obvious jam. Work ESAB's troubleshooting list in order.
Per the EMP 215ic manual: make sure the feed roller is the correct size and not worn; set the correct pressure on the feed rollers; and make sure the spool brake is adjusted correctly (not over-braked). Set them in that order before suspecting anything electrical.
Pull the tip and look in the bore — arc marks or scoring inside cause excessive drag and stutter.
The manual says to replace the contact tip when the bore is arc-marked. Use a Tweco Fusion-style M6 tip sized to your wire (the Rebel ships with M6 tips for 0.8 mm/.030 and 1.0 mm/.040).
Hand-pull drag, or aluminum wire that shaves and birdnests. The manual flags a bent liner causing friction against the wire.
For steel, make sure the steel liner (Tweco 42-23-15, part 1420-1103) isn't bent or kinked. For aluminum, do what the manual specifies — replace the steel conduit liner with a PTFE/Teflon liner and fit U-groove drive rolls; the smooth steel-on-aluminum path is what births the nest.