Going atomic!

Following the apparent underextrusion, I looked at various troubleshooting pages and decided to do an Atomic cleaning. The bottom filament came out looking stretched and somewhat rough, but not dark.

After this, a calibration cube printed almost as well as before - a few layers are gappy. Would another Atomic help? Or is it a question of adjusting extruder tension?

Cube #15: Slight wall stripping

One of the troubleshooting pages mentioned hole shrinkage, which I think I've been seeing. So I went to the original page on the subject and found a nice piece of OpenSCAD to do a test print (except it was using the outdated assign() operator, easily fixable). But even though it's but 3mm of print, it's slated to take one hour and 45 minutes! That's a long time. Maybe this would be the right time to test what happens if I speed up printing. Let's try a cube at 200%:

Cube #16: Wibbly-wobbly, half-timey-wimey

Decidedly wobblier, with a horrible top layer. The double skirt did its job nicely, though. For a last print of the evening, I try reducing infill speed to get the gaps at the top out (at 100% speed, because obviously 200% is bad):

Cube #17: No help for the top layer

Didn't make much difference, still has gaps in the top infill. Also the occasional underextrusion continues, including a hole in the bottom. The double skirt proves valuable again, though.