Retraction

[mucaco 0]

Hi,

I have the Ultimaker 2 updated with the latest firmware. Gcode is produced with Cura 15.04.4

Sometimes it happens that the printer perform retraction, not at the end when the head is moved to the new location, but in the middle of long straight line. This usually occurs in the bottom layer. Some part of the line is than missing and can cause problems on next layers.

I wonder if problem is known to anyone else, and how to prevent it.

Thanks.

[gr5 2,192]

This is very common. The problem is that the feeder stepper motor skips back because there is too much force on the filament (> 5kg). The bottom layer is thicker (.3mm) plus sometimes we level it a little too close (on purpose to get the part to stick well). To avoid this print even slower on the bottom layer. I usually print 20mm/sec bottom layer but consider printing even slower if you want it perfect. Or alternatively turn all 3 screws clockwise (looking from below) by 1/4 turn to give more space for that filament.

Also consider maybe increasing the temperature up to 240C for the first layer only. This makes the filament more like honey and less like toothpaste which makes it easier for the feeder.