MK4S - Circular Prints Failing
Hi All,
as you can see from this image, when printing any circles on my MK4S, which has recently been upgraded from a MK4, has suddenly started printing like the image below.
I have re-calibrated the gearbox cover and also checked the idler arm tension.
This filament isn’t that old and works fine on my other PRUSA MK4 (not yet upgraded to the ‘S’). The issue occurs on any board type, any filament (all PETG) and using generic PRUSAMENT Slicer setting - nothing changed.
Any suggestions?
RE: MK4S - Circular Prints Failing
That looks to me like poor adhesion to the bed and/or printing too fast. For reasons of inertia, the filament has a tendency to keep an straight trajectory. When we draw a circle, if the adhesion to the bed isn’t good enough or the speed is excessive, the thread of filament strays from the curve and takes the shortest path, as in the picture. You may argue that on a MK4S printer, the Z offset of the first layer shouldn’t be an issue. In real life this isn’t always the case, because of imperfect calibration of the load cell for different reasons. Even if the Z offset is correct, when the bed isn’t spotless, adhesion may become poor.
To be fair, I don’t see signals of a dirty bed on that picture. Besides, if the filament is PETG, adhesion shouldn’t be a problem even on a textured bed, provided that the Z offset of the first layer is correct,
If you have no problems with your other MK4 printing with the same settings, it looks like a Z offset problem. Nevertheless, I’d try to use adhesive and/or printing slower and see what happens.
RE: MK4S - Circular Prints Failing
Hi,
Are you using filament profile for mk4S ? I've used by mistake filament profile based on mk4 profile and print failed with similar problems (adhesion,...).
RE: MK4S - Circular Prints Failing
Hello, thanks for the speedy reply! I agree, I don’t think the bed adhesion is the issue here but I would say that the print speed is probably too fast! After listening to the printer print, there is a slight clicking noise as it prints and I have read that this can be to do with the idler tensioning.
I will also double check the tension of the belts.
Surely the presets of PRUSA PETG using PRUSA PETG Filament should work as that’s what they have based their settings on? And as long as I haven’t modified any of the settings, I can’t see why it wouldn’t be the same.
I’ll give it a go turning the speeds down but I don’t see the point in having a High-Flow Nozzle and MK4S if in reality you have to turn the speeds back down.