|Sorry, bad camera angle and lighting. Both have shifts to the right.|
As to what hit the X limit switch, I'm not entirely sure, but the only thing it could have been was the filament. The new spool holder is so friction-less that any torsion of the filament will wind more of it off...there was a single spiral of it above the print head when I noticed the layer shifted parts, but it didn't register as a potential cause.
Fix, filament guide:
|No idea why there's a line on the top skin. Also needs more |
extra prime at the Z seam (top left)
|As with most thingiverse things, there's usually something wrong|
with them. This slot was angled wrong.
I printed it at 30 mm/s inner wall, 20 mm/s outer wall and top/bottoms, 40 mm/s infill, 0.3mm layer height. The extruder started occasionally skipping on long infill runs, so I think ~30-35 mm/s is maximum feed rate at 0.3mm layer height. There's a locking cup thing you can print for it, but a piece of tape (with some more covering sticky part in slot) works fine to hold the filament in.
Lesson learned: filament holders aren't just for guiding filament. They're for keeping it out of the way and off of your X axis.
UPDATE: The above didn't help. It did the same thing again. Definitely filament spooling off and forming a loop near the x axis limit switch. Large x traverses seem to promote this behavior. I added a ~6 in piece of teflon tubing to the filament guide with tape. This prevents the filament from spooling off and forming a loop. I printed a holder for the tube that fits into the filament guide's hole that I will install with the next filament switch.
Better than tape