Fine tuning

I'm finding the fine-tuning of the 3D printing process to be quite challenging. I have spent a lot of time on calibration, and printed a few phantoms, and I'm very close. It is an iterative process, printing and measuring the phantom, and calculating new factors to program into the printer. This brings you closer to perfect, but it is not a one-step process.

The PLA settings are proving to be more difficult to get right than the ABS. Maybe I was lucky and got the ABS factors right by blind luck. I have been adjusting the rectraction length for the extruder to get as little ooze (stringing) as possible, and then went too far. This caused repeated jams INSIDE the hot-end, as soft PLA would be reversed out and when jammed in again, would distort and cause a shoulder which would not enter the J-head.

Currently I'm back to 15mm where I started. At the moment I'm struggling with extrusion width issues. In the lower layers, the width of a bead of plastic would be nice and thick, and I adjust the extrusion multiplier in Slic3r to give no extra material and no gaps between bead when filling. Once the print gets higher than about 2 mm (10 layers), the extrusion width drops to about half of the lower layers. This has the effect that a 100% fill has "gaps" between the lines, and because it varies (thin on one layer, thick on the next), it causes the edges of my print to be "wavy" and not a smooth wall.

I have tried to link it to print head temperature as set in the configuration (no correlation), instantaneous print head temperature (no correlation), I even calibrated the PID (with the M303 command), the settings were significantly different from the default, but I have not noticed a significant improvement. The instantaneous temperature can still get 15 degrees away from the set temperature.

But we learn about Slic3r settings every day. Setting "retract only when crossing perimeters" OFF causes the extruder to go crazy on the infill layers, it would retract and forward filament ALL THE TIME when infilling, especially on parts with small sections.

One of my PLA parts warped (one end lifted from the bed), so I'm running at 70 degrees bed temperature now.