After 10 hours of printing I have these spots on these couple of prints. They are not in the exact same location. Any ideas on what could be causing this?
It is likely contamination inside the nozzle. Could be tiny bit’s of previous filament finally worked it’s way out. It could also have been contamination in the filament but not likely. Another possibility is contamination on the build plate. I had that issue on solid white prints, I did switch to a new build plate but also had done several large one layer prints to ensure the nozzle was clean. I then got clean white prints.
i got the same problem. It can reduce the risk if you purge more material when changing the color. Or you should try to first print light colors and then go to darker colors afterwards
This may be caused by dust that builds up on the belts and carbon rods dropping onto the print. I had a similar problem in a single color print with defects that looked just like this.
Resolve this issue by wiping down all of the belts and the carbon rods with a microfiber cloth with some isopropyl alcohol sprayed on it. I did this on all 5 of my P1S that were having this issue and it has resolved it on all of them. Do NOT use a paper towel or it will leave paper residue on all the belts.
I am posting this in this old topic because I was looking everywhere for a solution to this problem and did not find a definitive answer anywhere.