PA11: sporadic drops of material during printing
Dear experts,
i'm printing on a MK4 (firmware 6.0.4, Prusaslicer 2.8.0 with up-to-date configuration profiles) using hardened 0.4mm nozzle and PA11 material (0,15mm, standard settings, 50% gyroid infill).
I'm experiencing repeated drops of (molten) PA11 material, it seems that some excessive material collects around the nozzle and at some point in time the amount has gotten so large, that it drops onto the print.
I have already controlled that the nozzle is properly tightened to the hotend and to the extruder.
When printing with standard nozzle and PETG or PLA the problem does not exist.
Any suggestions whta's the reason and how to solve the problem?
many thanks,
Roman
RE: PA11: sporadic drops of material during printing
Several possibilities :
1- Have you dried the filament ? Nylon is VERY hygroscopic and needs many hours in a filament drier/food dehydrator to be really dry. Even new sealed spools aren’t a guarantee. I know it by experience with the PA11.
2- 50% infill with nylon is pretty high. It’s better to increase the number of perimeters and keep infill lower for filaments with a tendency to warp..
3- Frankly, I don’t trust Prusa’s standard profiles anymore, specially after their abysmal implementation of input shaping (a generic resonance profile ‘one-size-fits-them-all’ ).
Lower printing speeds may help, although if you use the standard settings for PA11, the default max. volumetric speed will keep things controlled, so I don’t think this is the real problem.
What I’d do (in order of importance ) :
1- Dry thoroughly the filament.
2- Try a lower amount of infill and/or different patterns ( myself, I prefer rectilinear over gyroid ).
3- Experiment a bit with printing speeds, nozzle temp. and extrusion multiplier.
It seems that, in order to reach higher flows from the Nextruder, Prusa has pushed those settings too much with their standard profiles, That may be OK for PLA, but less so for PA11, For instance, a value of 1.05 for extrusion multiplier seems too high ( my setting on a MK3S is 1.00 ), On the other part, 285C for nozzle temperature seems OK with a hardened steel nozzle. ( I use 270C with a TC nozzle)
RE: PA11: sporadic drops of material during printing
Hi Artur,
many thanks for your very specific answer - incredible expertise around here...
I will try your recommenfations, indeed i have dried the material but this was 2 weeks before...
best regards , Roman