that's the down side of single sided cooling, try a different fan shroud or adding a second. the shroud on the umo is a very common problem, one that has been addressed by the community as a whole. for shee dependable cooling i go with gijs's v2 shroud and the right side counterpart to it, both are on thingiverse (sorry on a rush can't go find them atm, but you should be able to find them). but look around, as Ms. Frizzle would say "It's time to take chances, make mistakes, and get messy!"
For your first picture, that is most definitely due to the fan being only on one side of your print head. The splotchy side is not receiving any cooling so it droops more.
You can solve this one a few ways, make a small rectangle or any shape beside your main bowl about 5 cm to the right and 'print at the same time'. This will make the fan move over to the right side to print the square to ensure that that side receives some cooling. But you will be wasting a little bit of plastic on the rectangle.
You should also try lowering your temperature which may help with problem 2. 220 is pretty high for PLA. For the little splotchies, that's usually due to a bit of oozing before it goes to the next Z level. You can try increasing the retraction speed and distance a tiny bit. Again lower the temperature may help the oozing.
Link to post
Share on other sites