I got a Stratayas u print se and when it’s printing the raft, it isn’t flat nor smooth like it should. And it’s kinda bumpy. What are some reasons why it’s doing that?
Is the nozzle digging into the print bed when it puts down the very first layer? You may need to adjust the tip depth and/or the tip offsets. I often had this happen when I was reusing platens which often warp after 1 or 2 uses. Sometimes the nozzle will dig in enough that some black ABS from the platen gets pushed into the nozzle and then comes out when it crosses a low spot. If it is bad enough, it may strip the filament in the feeder depending on how long it is digging in or blocking the nozzle for at a time.
Nevermind. I took a closer look at the images. I would guess that either interruptions in flow rate or wet material may be the issue.
Does the uprint have a toggling head where the inactive nozzle is retracted much higher? If not, the nozzles may need to be realigned in Z.
Moisture was my thought too…