unpredictable horizontal bands on print - troubleshooting ideas?
Hello - I am trying to figure out what is happening here. Each time I print this file (there are three in the picture, left to right in order of printing) I get these strong horizontal bands at different heights. I have calibrated the PLA that I use (Hatchbox) using quality calipers, and get a perfect 0.45mm wall thickness for a calibration square in vase mode. I run at 1.00 extrusion multiplier, and I edited the machine g-code to run at 1.00 flow. I watch the first few layers of the print and do not see signs of over extrusion, the first few layers look very clean. What avenues of troubleshooting should I pursue next? For added info, this file used to print very cleanly, this phenonomenon is new.
MK3S+, Hatchbox PLA filament dried at 50C in a Sunlu S2 while printing, 16 hour print.
I run the stock extruder and the Delta-P cooling fan duct instead of the stock cooling duct, but the print was fine for a while after I installed this.
I'm pulling out what remaining hair I have, any thoughts? Thanks!
Banding issues?
RE: unpredictable horizontal bands on print - troubleshooting ideas?
Could they be layer shifts? Instead of Banding?
If your grub screws on your X and Y Motor toothed wheels become loose, you can get layer shifts which move back and forth randomly, by about the same distance, these shifts tend to get more regular with successive prints, until the problem is resolved.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: unpredictable horizontal bands on print - troubleshooting ideas?
Can you use your callipers to measure the precise heights of the different batches of parts.
I'm wondering if you have some mechanical problem stopping your z screws working properly so the extruder isnt moving up properly and so giving you squished layers. If thats the case then the parts wont be quite the height that were sliced at.
Good thinking @neophyl.
@bryan-barney - to help us rule out another, possibility, please show us both sides of one of your banded prints.
Cheerio,
RE: unpredictable horizontal bands on print - troubleshooting ideas?
I should have done so, yes (shown both sides). The other side is the same, it's like the print got fatter in all x and y dimensions at those z heights, different z heights each time it was printed - even on the inside of the cups.
RE: unpredictable horizontal bands on print - troubleshooting ideas?
potentially solved....
In order to start from a 100% flow 1.00 extrusion multiplier for "calibrating" filament, I changed the starting g-code for my machine from
M221 S{if layer_height<0.075}100{else}95{endif}
to
M221 S100
When I changed it back to the original code (S95), the problem went away - I must have changed this after the calibration cubes were printed, since they were perfect and the prints were clearly overextruding.
Thanks for the read - if you find this, I hope it helps you!
RE: unpredictable horizontal bands on print - troubleshooting ideas?
Are you printing one or more at one time? If you are printing two at one time, do the bands show up at the same height? Have you tried a different print that is about the same height?