I've lost the formula, somehow. I've made lots of okay prints over the months. I've rebuilt both extruders (new PTFE of precise length), nozzles cleaned, all tightened, cleaned drive wheel. I've upgraded to PTFE feed tubes plus the spring loaded drive mechanisms. I'm just doing single filament PLA, and I'm using the same filament that I've used for quite awhile with success. I installed Sailfish 7.7 as well. I've also got ball bearing spools.

I'm getting drive clicking no matter what the temperature (although I haven't tried above 250, since I've read some things about going too high). I thought it might be a bad thermister, but either extruder does the exact same thing. I'm wondering if there's some way my servo drive signals might be "weak" or something. If I hand force the filament into the drive it goes away, but otherwise, it clicks. At 250 it works for a few inches then clicks, and I can see the thinness of the extrusion. I'm using 40/70 as my speed settings.

What the heck am I doing wrong? The weather has gotten a little more humid, but I don't see any sign of bubbling in the print.