intermittent extruder gear 'clicking' with a failure to feed

I am experiencing an intermittent failure to feed in mid print. During a print, the extruder gears will jump as if the filament is jammed. Then filament will feed just fine.

My setup:

• i3v 8" with a e3d v6 3mm hot end and a greg's extruder.
• the thermistor on the hot end is one of the parts that Colin offers as 'pre-built'.
• ABS (from Makerfarm) at a head temp of 225.
• Octoprint

The event seems to happen in mid stream without a common element. I have levelled the bed, and in the course of troubleshooting, found a couple of loose points on my printer (the eccentrics on the bed needed a twist and the heat break was not entirely tight in the heat sink.)


Even after fixing these issues, the gears jump mid print.. then feeds just right... then jump again. I would think that it is back pressure as if I cancel the print, set the hot end temp, raise the carriage, it extrudes, however, this intermittent 'bug' has resisted my efforts.

I've had several successful prints and now this problem is ruining prints. I am at a bit of a loss where to look next, so any suggestions are very much appreciated.

Chip

Have you checked the settings on the stepper drivers? My extruder would behave exactly as you described until I turn up the voltage a small bit on the stepper driver.