Bad flux - bad calibration - HELP

Bambu Lab H2 Series
1

for unknow reason i keep getting bad adhesion between PLA and TPU using both nozzle.

just imagine printing 2 rectangle flat on the bed one is inside the other, all the wall touch and the middle is hollow.
right and left are fine,no issues, i would say bottom is also ok, but moving north ( toward the back of the printer) they get separated, and i don’t know why.

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and that was not the case before, i have printer that same model before so i don’t get it

i reset the printer to factory, still happening

redid all calibration of the printer, still happening

so i am moving further into calibration of the machine

did a debit calibration, i was having issue with LEFT nozzle, could’nt get the test to stick to the plate, TWICE, while the left nozzle was printing fine and was able to finish both calibration, so not a plate issue.

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for the right nozzle since the calibration print was coming loose i figure skip that test and move to the second part, because it was really scrapping the print, so every time i tried, part of it were becoming loose

so i manage by skipping first part and moving to the second, printed fine

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moved to flux calibration, but that part gave me really poor result

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because it seem to move UP a bit

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is my print head broken ? because last time i did this test those line were not that thick

and that can be seen also on the botome line that is drawn

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2

You’re not supposed to rely on the adhesion between TPU and PLA. You’re supposed to print them in a way that they interlock into each other. There’s no way that the adhesion between them would be good enough.

Also, clean your X gantry rail, there’s something causing the deformation of your lines, if you haven’t noticed yet.

3

sorry, for my bad english, what i meant to say was that the print i do usually has good adhesion between TPU and PLA, so that gap that i see, i never got it before and i don’t know why its happening, wierd part like i said i only get it on one side of the print, the rest is fine, no gap at all

4

I don’t know what you mean, but your X rail seriously need to be cleaned before permanent damage happens (if it hasn’t yet). If you need translation, use ChatGPT to do the translation, otherwise it’s very hard to understand…

5

i corrected my previous comment, but how could the X rail get that much issue ? i have printed maybe 60 hours top, under 100 hours for sure.

so far the issue i got was a bad adhesion that broke the cover that move between nozzle, i change it, and what is strange about the issue i am having is that everything else print fine, the line are perfect, no fuzzy result

the last picture i posted, that the first time this is happening

6

some thing dirty on your x rail maybe? or some debris fell into the rails? it’s very hard to judge without access to your printer. sorry.