Ultimaker 2 nozzle movement scratches the print.

[juj 0]

Hi,

I noticed while printing the base of this object http://www.thingiverse.com/thing:788360 that the printer systematically makes scratches to the bottom layer, which are quite visible as a result. Here is an image to show the effect:

The left one was printed with Cura "high quality" default setting, whereas the right one was printed with the "Normal print" setting, but in the Expert settings, "Z hop when retracting (mm)" was set to the suggested 0.075. Both prints were done with Platform adhesion type = None on a clear build bed.

The scratches look systematically the same, and I observed that the nozzle travels through that pattern during printing, as also seen in the Cura software:

Has anyone observed something similar? If you have suggestions on what settings to use for a "please don't scratch my print" configuration, I'd be very happy to hear!

[gr5 2,210]

There is a setting related to retraction called "enable combing". This tells Cura that you don't have to hope or retract as long as you are "inside" the outer shell and so movements will stay inside the part (for example if the part is C shaped it will move within the boundary and not cross over open space). Unchecking this option will enable more retractions on the bottom layer.

An alternative that works really well is to change the cad model such that the bottom is solid and the 4 holes start on layer 2. Then just drill out the holes. You will get a much nicer look.

[Dim3nsioneer 557]

Another alternative:

https://github.com/Dim3nsioneer/Cura-Plugins/wiki/Retract-While-Combing-plugin