need help with extrusion problems

I have a dual extruder Prusa with MK8 heads and direct drive steppers.

My prints are beautiful until they just stop extruding and i find my nozzle going to town floating layers above the print being no productive. This often happens many layers and an hour+ into the print.

Ive played with the tension and temp for hours. I even went so far as to very gently file one of the driver gears down a little so it wasn't so sharp. I've slowed the overall rate to 65%.

The extruder steps are calibrated and accurate to within 1mm in 100mm.

Same outcome. Prints great until it just quits producing filament and i find a ground down section in the mechanism. Any lighter tension and it wont pull.

Do you guys have any ideas?

Thanks gents,

Zan

check to see if your filament is wound in such a way that it is snagging - try different filament is that is the case.

Check your nozzle and make sure it is not plugged. If the filament is ground down inside the the extruder something is jammed and not allowing the filament to feed through the extruder. You can also try to feed the filament through the extruder once your nozzle has been removed to verify this is the point of your problem.