Infill % Affects Perimeter Speed
I just switched to a 0.6mm nozzle so I decided to check my volumetric flow rates. I noticed the perimeters on solid infill layers (top and bottom) matched the speed settings but perimeters on 20% infill layers were much slower than the speed settings. The smaller the infill percent, the slower the perimeter goes.
I'm looking at the speed view so I don't have exact numbers but the change looks like this:
100% infill = 50mm/s (matches speed setting),
20% infill = 35mm/s,
10% infill = 30mm/s,
0% infill = 17mm/s.
It also seems to be hitting some limit that I can't find because I can't get the volumetric flow rate to exceed 5 0r 6 mm3/s when printing at 10% infill (maxing all settings). It will hit 15 mm3/s if I change infill to 50%. This also seems to be affected by the number of perimeters, more perimeters = higher speeds. This is likely a way to limit extruder pressure on a thin wall but It doesn't seem very smart. A very short wall can handle much more extruder pressure than a tall wall but changing the height of the part didn't change the speed. Is there a way to override this limit? I tried it on 2.4.2 and 2.5 with the same results. All infill types worked the same. I'm printing a small airfoil cross section thats 100mmX12mmX12mm.
RE: Infill % Affects Perimeter Speed
It’s probably the slow down if layer time is below value you are hitting. That is located in the filament profile and not the print settings.
It’s a common one that catches people out. If you post a zipped up saved project file we can confirm. Must be zipped or the forum won’t allow the attachment.
RE: Infill % Affects Perimeter Speed
Thanks Neophyl, that was it. Now I know why my tall skinny parts take so long.
RE: Infill % Affects Perimeter Speed
Just set that time value to something like 5 seconds. That what all my filament profiles use and that seems to work ok on everything except really thin things (like 3mm posts). Still have to print a couple at a time spaced apart for those.