Hi there,
I must admit, I am not using an Ultimaker printer, but I built one myself. I am using the wonderful Slicer Cura, which (as I think) is the best one on the market.
Overall, my printer prints beautifully, but lately, I discovered a new problem. I had not printed in a long time and I am not sure when this problem first arose. I am printing quite a complex part, about 19 hours to print in total (picture 2). I am using a bowden extruder. Some parts of the model are printed really well and smoothly without any reason for complaints. But some parts (especially the ones with holes in it) are printed with missing material. The wall thickness also seems to differ. I would suppose that it had something to do with retraction, but reducing retract / prime speed did not solve the problem. Also, I do not understand, why this problem occurs only on certain parts of the model. Picture 1 shows another model with a similar issue, but overall much better quality.
I tried to reproduce and isolate the problem (picture 3) by printing a very thin wall (0,5 mm). Here it can be seen clearly that somehow some parts of the wall are printed thicker.
I am still doing testing, but I feel a little bit lost here. I hope you can help.
Details:
Material: PLA
Print temperature: tried 200 °C, 210 °C, 220 °C
Print speed, outer / inner wall speed: 30 mm/s
Infill speed, travel speed 40 mm/s
Small feature speed: 10 mm/s
Small feature max length 20 mm
Retract amount 6,5 mm
Retract / prime speed 20 mm/s
Layer height: 0,2 mm
Nozzle diameter 0,4 mm
Kind regards
René