Hoping someone can help, I'm pulling my hair out over here. I can increase the flow, but it's already over extruding and I feel that's just a band-aid fix, not really getting to the root of the problem.
I've calibrated my e-steps, and rechecked them last night to confirm they're still correct. Filament is 3DFillies Silk Red PLA+, and eSuns Black PLA+ (Both measure at around 1.73mm).
I have attempted to calibrate flow, by measuring the perimeter/line width on a hollow 20mm wide cube (also later a 35mm perimeter test model). If anything, it's consistently measuring 0.43~ on single perimeter tests, and 0.83~ on 2 perimeter tests. So if anything, I should adjust my flow under what it currently is. But I'm not going to do that, as the top surface and some perimeters have noticeable gaps/under extrusion.
I've observed the print (MPCNC FOOT, PICTURED IN RED) in eSun Black PLA+ and noticed that in the bolt hole (pictured 2nd and 3rd below), it starts off perfect but about 3/4's up it starts to develop gaps in the perimeters. The perimeters in the first 3/4's is identical to the final perimeters, atleast according to CURA tool path. I've also noticed on the 4th layer of the bottom layer, it under extrudes in certain areas, particularly corners that have short tool head travel as pictured in the 1st picture).
I've also checked the tool path in Cura, and I don't see any gaps in the perimeter/surface.
I'm using:
CR10S (TH3D Firmware U1.R2.A8, EZABL + E-Step Calibrated)
PLA+ from two different companies at 1.73mm thickness (-0.02mm)
Cura 4.6.1 (Stock Profile, Except 4 perimeters & infill changed to 40% Cubic)
Brand New Creality 0.4mm Brass Nozzle
Also bonus question, there's zits that appear inside the channels for tightening the bolts. No idea what causes it, but it was also happening when I initially went to print these all using a 0.8mm nozzle. I've changed settings on the seam, and it doesn't appear to be zits from the seam. My best guess so far is that it's heat related.
Other than the surfaces, the print is crazy good. The best I've ever printed, pictures don't do it justice. I want to drop down the flow rate to match the line width, but there's obviously something wrong that's causing the skins and some perimeters to under extrude. It ALWAYS defects in the same areas, consistently. It's not infill density/amount of layers, as it still happens on the 4th bottom layer which is obviously fully supported.
(Above: If you look closely, top left/bottom right of the tube hole, it's under extruding on the skin. Perimeters appear fine!)
(Above: 1 of 3 bolt holes, perimeter is pretty much fine, only a very minor pinhole)
(Above: 1 of the 3 bolt holes, gaps in perimeters. Same tool path all the way up, but only ends up with gaps when it gets closer to the surface)
(Above: Zits, not Z seams, I'm guessing an heat related issue from the shape of the bolt hole channels)
(Above: Doesn't appear to have gaps in the perimeters, though the black filament does make it look like there is. But the skin is pretty under-extruded.)
