Question: Why does Cura print a 1 wall circle with 2 inch diameter NOT in continuous motion?

[Xaevir 0]

Im trying to print a 1 wall circle with 2 inch diameter. The nozzle starts extruding smoothly in a continuous circle then stops jumps ahead prints in reverse then runs over the previously extruded layer. I upload a .gif if that doesn't make sense. Any clarity on this issue would be amazing.

[GregValiant 1,251]

How did you define the Z seam?  If it's Random then what you're describing can happen as Cura moves the layer starts here and there around the periphery.

Combing can make the nozzle run around the circle as it avoids passing through the center to prevent stringing.

 

Since it's a single wall model - did you consider Spiralize Outer Contour (or does the shape of the model prohibit it's use)?  Spiralize doesn't work on horizontal surfaces except for floors so if the model needs a roof it wouldn't work.

[gaduffl 0]

Hello!

I have exactly the same issue. Cura seems not to be able to print a single walled circle in a continuous motion. It completes part of the circle, moves back over the already printed wall and then completes it. With some settings like combine and Z-Seam position altered, it completes the circle in one motion, but then the nozzle travels back 360 degress without retraction to the point it just stopped, and only the changes the z-height.

This leads to a loss of material from the nozzle, and the start of the next layer is seriously under-extruded.

Prusa Slicers is not doing this at all with the same model.

 

This issue with the circle is however only a simple example, since the unneccesary travels also appear on other models. This leads to ugly under-extruded starts of the layers.

I cannot fix the under extrusion issue, since it seems to be related to a too high pressure on the filament during transport, but my printer does not have any possibility to adjust this. So fixing the unnecessary Cura travels is the only way to fix this issue.

 

I attached the example with the ring for reference.

 

Thanks for your help!

CFFFP_ring_test.3mf