Nozzle lifting itself while printing first layer
Not sure what to make of this, but during printing, the nozzle keeps lifting itself higher over time. In the pic you can clearly see a nice first layer to the right, with slowly a gap forming towards the left. The gap disappears when lowering the z-offset by -0.05 mid print. I have to continuously lower the z-offset during the first couple of layers, after which it seems to stabilize.
So this is what I have tried so far:
- 1 -2hour bed heat soak
- 10 min nozzle heat soak
- Stable chamber temp @45c
- Titanium x-gantry
It doesn't seem to matter if I do a 1 hour or 2 hours heat soak, the lifting starts when printing starts.
What on Earth could this be? Nozzle shrinking due to filament flow?
With the aluminium x-gantry the nozzle was going down over time, so things could be worse 😄
3 Replies
I'm thinking this might be underextrusion. It seems the extrusion multiplier in Prusa has been set to 0.92 for some reason...
OK, it was definitely related to the extrusion multiplier. After crancking it up all the way to 1.05 it seems to have solved the issue.
Does anybody have a good way to calibrate this vs z-offset? If you do a first layer test you can easily mistaken underextrision for too high z.
Just do flow test... Its several layers high, so the squish evens out and Ou see your actual flow on top...
Then when you have your extrusion rate set dial in first layer squish
Done that now indeed, thanks.
Just to update, it had nothing to do with the extrusion multiplier, but in the end a Beacon re-calibration seemed to have fixed it. Maybe the original calibration got killed in some update or something, I dunno.