Temperature Towers and other tweaks

As mentioned in the last post, I did some temperature towers (using Bob's sneaky gcode) and found better settings for PETG. The standard towers are a little too detailed to work well with the 0.8mm nozzle, but I tried anyway. Here are the Fast Informative Temperature Tower, at 4 different retraction rate settings (default 1.4, 2.0, 2.5, and 3.0):

String galore, but less so at about 220°C and 3mm retraction. I don't think I want to retract more than that, I see several sources saying it can lead to hot plastic getting too far up towards the PTFE tube.

My 0.4mm nozzle was pretty full of PLA. I didn't want to scratch it using any kind of metal tool, instead I heated it up in a candle flame to get the PLA soft enough to run out. I would have preferred a butane lighter, but ours was out of fuel. The PLA didn't run out on its own, but I was able to attach a piece of filament and 

For PETG, I'm using the steel powder bed, as the smooth one just doesn't let go of the print, and for the 0.8mm nozzle with 0.4mm layer height, I have calibrated it to a Z level of 1.150. The layer height does make a difference for that. 

I'm using the stealth mode more. It is really a lot quieter (average 46dB instead of 52, measured with a phone app, the phone lying right in front of the printer) and only minimally slower, but it turns off crash detection, which I definitely want to have on when starting a print and leaving. When I'm watching the print, it's not so bad.