Printhead all over the place.

[spooner777 0]

Today I had some extrusion problems, removed the hot end a few times and now it printed about 1cm z-height and the printhead started to go all over the place. It kept extruding well though and extruded something cotton like. The printhead was in areas where it did not belong. What could have caused this?

I used Cura 12.07 and used the same file with the ulticontroler that worked a day ago.

[spooner777 0]

I also noticed that the small fan is not activated automatically anymore.

[Daid 306]

Cura activates the fan on the 2nd layer, not on the first one. This improves the adhesion of the first layer. Maybe that's your fan problem. No idea about your other problem...

[jcosmo 5]

I've had the printhead vanish off in strange directions when the pulleys are not properly screwed onto the drive rods.

[spooner777 0]

I think the pulleys are alright. It does print the first few layers ok.

[Daid 306]

But the first few layers are printed at a lower speed, so you could be having issues at higher speeds, which can be anything from lots of slack in the small belts (so they jump over the pulleys), lose pulleys or too little power on the step motors.

[spooner777 0]

I had 5 different issues that night. I did nothing for 2 days and now it printed completely normal and in good quality.