Modified extruder knocking sound problem

[kazzaqov 0]

Hello everyone.

I have a modified extruder, not exactly sure what model is it, but looks similar to Airtripper's Bowden extruder (http://www.thingiverse.com/thing:35404)

So recently a problem appeared: extruder is making knock-like sound when printing. The one you would expect like if the speed is too fast, but the temperature is not high enough. When printing the first layers, good bed leveling might help, but to fix the extruder sound I need to lower the bed too much, so that the first layer would not stick at some places. And if I print with that sound, the nozzle often will jam and the print will fail. But the problem is, that this sound appears not only at the first layers, it continues to knock during whole print. I had no such problem with the extruder before, even when printing first layers too close to the bed. Tightening the screw on the extruder makes knocking faster. Untightening leads to underextrusion or filament slipping off the extruder. Tried different speeds and temperatures.

Here is a video:

Any ideas how to fix the extruder? Thanks in advance.

 

[kazzaqov 0]

Untightening screws on extruder seemed to fix the problem after all. The topic can be deleted I guess.