So... My third attempt at a print larger than a 1cm ball. I'm printing ABS. Because, why not throw yourself into the deep end when you build your first printer, right?
I made a post this morning about def thermistors and other strange issues. Here's another one.
While printing this test print, I watched it carefully the whole time. The raft printed nicely and then the temp started plummeting. Here's my notes that I frantically typed down:
Bed heat plummeted to sub 60 after 2% of the print despite heat LED being on and set at 95. Approx 0.2 deg per second. I can hear snapping and popping of the raft - part must be cooling enough to allow relative motion of the coarse extrusions and delamination from the bed. Temperature at 54 after several minutes (3% printed). This print is at a similar location as the last time it failed (which was also the first time I tried it). A few mins later, bed at 52, still 3% printed on lcd.
Raft has delaminated on one edge of the ~4.5 inch diameter and both thermistors now read def. still 3% in.
Immediate reset using red LCD panel button reads temps fine immediately.
Bed can be set to 80 at the LCD and heats like normal.
What the what is going on!?

Thanks for the help...