Surface Marks Printing in Cura with Mini & eSun HIPS

I got a Lulzbot Mini recently and have been methodically tweaking Cura to get better and better prints with HIPS thanks to all the great forum topics and tips and I’ve cleared up most of my printing problems except one. There seams to be the same scars on the surface of every printed object that has a flat top. I’ve watched the printing process and it happens when there is a large travel between extrusions. I have made numerous tweaks to different settings one at a time as suggested. I’ve measured the filament diameter and entered that. I’ve adjusted the Flow. I’ve made tweaks to Retraction settings. and while the overall prints have improved, the surface marks remain unaffected. I’ve hit a wall. Has anyone else experienced this? Here is a photo of a sample object I’ve been using and every one has the same scar from the top left moving across to the mid right of the objects. Any help is sincerely appreciated.

I think everyone with a FDM printer experiences this. :slight_smile:

Those striations are the filament being deposited. When the filament comes out of the nozzle, its more or less round… when you put two cylinders side-by-side there will always be a channel where the two touch.

To check if you’re overextruding, feel the perimeter of the infill. If there is a pronounced ridge where the infill overlaps with the perimeter, then reduce the flow or extrusion multiplier by 1% until its fairly even. At that point you may be underextruding, but the top surface should be “smoother”.

FWIW - I think you’ve got the machine extruding nicely.