Inconsistent bed adhesion and printing quality
I've been having some problems with my MK4S recently. For a long time it was working perfectly the print reliability has slowly deteriorated over the last few months. It started with some random failures: stringing, bad support interfaces and just generally failed prints. It's been a few months since it started and I did a lot of tweaking, rebuilding, and tweaking of slicer settings. Since then it's been a few months and haven't done much printing since. Today, I got some inspiration to test printing benchys at different locations on the build plate. Interestingly, that actually seemed to make a difference. The picture below is an attempt at illustrating where each print was located on the build plate during printing.
Out of the 7 prints I started only 2 finished and they looks to be about the quality I had come to expect from my 4S! Interestingly, these two prints were both very near the center of the build plate.
All of the rest of them either ended up stuck to the nozzle or generally just detached from the build plate at approximately 10-15% through the print.
All of the seven were printed in approximately the same operating conditions with identical slicer settings:
- 0.4mm hardened nozzle
- silicone sock on the hotend
- stock nextruder
- black 1.75mm PETG Prusament
- slicer settings: unmodified (other than supports) prusament PETG, 0.20mm SPEED profile, MK4S 0.4 nozzle printer
- firmware: 6.2.6
- brand new textured powder-coated build sheet from Prusa
Any advice is much appreciated. Im more than happy to run some other test prints, disassemble/re-assemble components or just generally try things out. Thanks!
RE: Inconsistent bed adhesion and printing quality
Did you print these parts in the image one after the other (by object) or all together by layer?
RE: Inconsistent bed adhesion and printing quality
Each was printed individually (by object) one after the other with a re-slice and export for the new location
RE: Inconsistent bed adhesion and printing quality
Brand new build plate? Hmmm.
I suggest washing it with hot water and dishwashing solution, such as Dawn Ultra (in the USA). Make sure it doesn’t contain hand softener. I fought the same issues as you described until I realized that the Palmolive I was using was the problem! After switching to Dawn, the parts almost stick too well!
Best of luck!
MK4S/MMU3
Check there is nothing under the print sheet or stuck to the back. Lay a straightedge across the plate and check for flatness - If it's not too far off there are remedies but check first.
Cheerio,
RE: Inconsistent bed adhesion and printing quality
>> Interestingly, that actually seemed to make a difference
PETG is more prone to warp than PLA so adhesion matters.
There isn't consensus on the topic but IMHO cleaning the print sheet consistently (!) especially when multiple materials are involved is more tricky than it might look superficially. There are subtleties involved e.g. that pure IPA doesn't necessarily dissolve PLA residue (lacking water) and doesn't bind to fatty contaminants (as soap would do), just moves them around.
A spray can of a dedicated adhesive/separating agent was my most efficient investment in 3D printing, next a drier (15x more expensive but IMHO mandatory).