Random, uneven, extra retraction (?) noise during print
Hi!
I come with you with something that drives me crazy. Take a look at video, and listen to sounds of retractions. There are two different sounds, one being much louder and harsh. After this sound, first few mm of layer is barely extruding. It really messes up print, so I've been trying to locate the source.
My retraction settings are 30mm/s both ways with 3mm length.
I've tried different profiles, no change. Tried IS and non IS. Tried slower (30mm), tried faster printing speeds (140). Same thing
Every X (and x is random) layers, after normal retraction, this extra 'retraction' happens (at least I think there are two of them).
I've tried switching off every overrides for retraction for filament, I'm honestly out of ideas. It happens on few early layers, then is not present in middle of print, starts happening again close to end:
I attached gcode that reliably gets this sound and printing issues. It's really simple, 40mm cube with no infill and one perimeter (not vase mode).
From hardware, I think it's worth to note I'm using Bondtech dual gear extruder.
Edit: since pasting video somehow gets ignored, here's direct link:
RE: Random, uneven, extra retraction (?) noise during print
Attaching files also doesn't seem to work for me.. Here's gcode: https://drive.google.com/file/d/1TosgGB7U-buOuQeGHBzral7pmWp2mKCL/view?usp=drive_link
RE: Random, uneven, extra retraction (?) noise during print
I found out (most likely) what causes this and I can reproduce it.
For sake of people having this in future looking - this sound starts appearing on retractions when extruder is at it's limit. What I think happens is that there is tension on extruder due to extruding more than there's space, which get's released on next retraction.
I was able to reproduce it in two situations:
- print speed too high and volumetric rate higher than recommended (ie. 10mm3/s on PETG)
- high pressure advance (>0.9)
So if you start hearing this, it means somewhere in your setup you went too fast/hard 🙂