Printed ended looking like a ball of wool
Hi All,
MMU finaly works with 1 color with out any issues.
I tried a dual color calibration cube and the sheep which come with the drivers
For the cube the print was sucessfull but I obersved the purge block started to loosen towards the end of the print.
For the sheep the filament changes worked but the print ended with the last 30% printed "into air", thus looking like a ball of wool.
At least the print ended with removing the filament as expected after 7h of printing
May be one of the objects got loose. Due to space contraints I can´t install my camera to record the print
I tried to add a brim but this doesn´t work for the purge block. Is there a special requirement for bed adheasion using MMU2?
I cleaned the plate with water/soap as well as Isopropanol several times
Any other issues I might miss?
I feel I´m close for my first scessfull dual color print after working on this for 4days now
Re: Printed ended looking like a ball of wool
I have problem with prints not holding on bed (MK2.5, fw 3.4.2, disconnected MMU2 unit). It seems that the issue is caused by Z not being adjusted by the value from 1st level calibration. I created the report here: https://github.com/prusa3d/Prusa-Firmware/issues/1293 .
Are you having the same issue? How does your print look from bottom?
Re: Printed ended looking like a ball of wool
In my case the z calibration seems to be ok. Just the purge block doesn’t stick enough,
Thus ruins the print after 5h printing
Re: Printed ended looking like a ball of wool
Wipe the bed with acetone. You could also lower live-Z 10 to 20 microns.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Printed ended looking like a ball of wool
Thank you PJR,
Acetone seems to do the treat. The 2h bicolor cube was perfect, now the sheep is printing again.
Fingers x-ed this will work 😀
Re: Printed ended looking like a ball of wool
It worked 
1st sheep had a bit carry over, 2nd with higher purge volume is almost finished
Just wonder why it took me soo long to get the printer working as it is in the stock configuration,
just the spool holder attachment is missing.
3 more colors to go 😀