I am currently in talks with support but after running the tests they sent me they have now forwarded the issue to R&D for further investigation.
The printer prints ok for 2-3cm in height and then z-banding appears. I have re-lubricated and re-calibrated the printer a few times. Slowing down (50%+) helps but does not solve the issue.
Support sent me 2 tests. One with a single object which printed PERFECTLY (single blue one in my hand photo - I think I noticed the speed was really slow) and a 2nd test with the same object in 3 copies. This one was bad. The banding is there and there are layer adhesion issues too like my own prints.
I have checked for loose screws etc on all axis.
I have tried both PLA and PETG with the same bad results.
Z Banding/Z Wobble can have a lot of reasons. From bad filament, a bent lead screw, problems with the lead screw coupler to a (partly) clogged or worn out nozzle.
Maybe this article helps to identify the problem and solve it.
I have tried various filaments, used a SUNLU dryer to directly feed PLA, double checked the coupler and motor screws and also the nozzle which I removed, cleaned and put back. The lead screw I can’t be 100% sure it’s absolutely straight but the printer is almost brand new and also prints the single test model perfectly so I almost rule that out too.
something is not right and it’s getting harder and harder to identify what.
A benz lead screw would lead to a clearly periodic pattern. Had that on my old Tevo. So I’d guess that it is not that.
From the pic’s, I’d look at temps, cooling/drafts, double checking that the PTFE tubing is clean/new and, actually before doing anything else, drying the filament.
Is your wall generator set to Arachne vs Classic by chance? There is a known issue where Arachne doesn’t work well with the new Smooth Speed Discontinuity Area feature, and for which a hotfix was recently released. I just had a print exhibit similar banding out of the blue yesterday (after the hotfix) and turning off Arachne solved the issue.
I haven’t touched the default settings at all. Using Bambu PLA basic and the settings coming with the software. I re-tensioned the belts and replaced grease with WD40 multi-use and got much better results but still not perfect… I still get banding higher up.
Was a solution ever found for this? My A1 mini is experiencing the same issue. If I print a single object the results are perfect. Printing multiple objects results in banding for some, but not all, objects. The banding occurs at random layers across prints. Sometimes I get under extrusion instead of banding.
