Grid infill with PETG

Hey there,

problem is that when doing grid infill with general petg profile, i noticed there’s a large amount of filament accumulating on the nozzle. Eventually it falls of somewhere during the print, with no guarantee it won’t ruin your print. Also noticed that it does start to happen when grid infills are being printed. Changed to gyroid - problem went away. However I liked the grid infill because it causes less vibration doing straight lines.

Any suggestion how to solve the filament accumulation on nozzle while printing grid infill ? Thanks

You can try to turn of the “reduce infill retraction” checkbox in the others tab of your slicer profile. But that is checked by default for good reasons so it may be not the best thing to do. It increases the risk of clogging and underextrudion on the start of a new layer.

I hate grid infill with passion, especially with faster printing like Bambu does or with filaments that expand a bit after extrusion it just sucks. Try Rectilinear infill or print with merged infill layers (called Infill Combination in my slicer, I’m not sure if the original Bambu Studio has it, PrusaSlicer allows you to set the nuber of layers to merge).
Another option - use thinner lines for the infill.

Of course if you need strong part, then grid makes some sense, but then you shouldn’t care about speed so much not to use gyroid (not sure whether it’s actually the same strength…)

I saw a slight improvement after increasing the nozzle temperature a bit.

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That might work for smaller objects where the filament stays plastic, try a large box with grid infill - you will start ripping your layers to shreds at default speeds no matter the temperature…

That was going to be my suggestion. Grid infill is great for strength because the horizontal lines get printed on the same layer as the vertical lines with no retraction, so there’s a very strong connection at the nodes of the grid. But it can cause boogers if the nozzle temperature is too low or if there’s already enough buildup on the nozzle that the automatic cleaning won’t get. With PETG the solution to every problem is generally “more heat.”

Thank you guys for your ideas. Interesting indeed. I didn’t know that there are so many differences between grid and rectlinear infills. Will try to fiddle with these two.