Calibrating my E-steps is not going according to plan. Based on my results, I feel there must be some slippage going on in the extruder. But I cannot detect the slippage by watching/listening.

After applying the linear corrections predicted by measuring a 100mm gauge length, the new E-step values were bouncing all over the place. So I abandoned the linear correction formula [new = old / (100 /measured extrusion) ] and just tried some various values. My results:

E-steps = 900 , caliper measurement = 27.4, extrusion length = 92.6 mm
E-steps = 910, caliper measurement = 25.8, extrusion length = 94.2 mm
E-steps = 960, caliper measurement = 13.6, extrusion length = 106.4 mm
E-steps = 935, caliper measurement = 31.8, extrusion length = 88.2 mm

The trial with 935 extruded significantly less than the trial with 900, so something is not right. And subsequent trials with E-steps set to 935 yielded caliper measurements of 31.8, 25.7 and 14.5.

I have tried cranking down very hard on the guidler screws, and I have tried backing them off. The bearing in guidler turns freely. What else can I try?

Jim

10" Prusa i3V, 3mm natural PLA, 185F, 0.4mm Hexagon