Issue with grid infill
Had an issue with grid infill while printing PETG. I noticed this also on my MK4. Did not have this issue when it was a MK3S, but as soon as I started using input shaping on the MK4, the issue cropped up. This photo is from the XL using input shaping. I'm assuming that it is speed related. Prusa suggested changing the infill to gyroid as it doesn't cross over itself, which seems to be part of the issue. that did indeed fix the problem. 2nd phot is the same part with gyroid infill.
Grid infill is one of those features that has lingered a little too long. I assume Prusa continue to provide it as it is referenced so often in early 3D printing articles, in practice, with todays much higher precision printers it is frequently a poor choice.
Prusa's stock fallback suggestion of gyroid is one that is almost always going to work although it may not be ideal - your structure would probably be better served (and printed faster) with cubic infill.
As a rough guide: Cubic and its variants for speed and rigidity. Gyroid for resilience. Honeycomb for rigid parts without directional bias (but you won't need it often, and it shakes the printer.)
Cheerio,
RE: Issue with grid infill
With PETG and IS, grid really "shines"--and not in a good way.
Why grid is still the default is beyond me. Well, not really. I guess it's the fastest and for whatever reason the world seems to be more obsessed with speed than quality.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...