Quote Originally Posted by uncle_bob View Post
Hi

As soon as you try to put the pcb on something firm enough to keep it flat, you either bow it upwards or you suck enough heat out of it to mess up the thermal performance. The real answer is to go to an aluminum heat bed with a silicone heater if you want to use inductive bed leveling.

Bob
Gee I guess someone forgot to tell my unit that because it's been working flawlessly for 3 straight weeks and I print constantly. I also have no problem running the bed at 115 C which is as high as I've needed it to go. I also ditched the relay for a SSR and went back to PID regulation because bang-bang sucks for anything with a short (less than several minutes) on/off cycle. I could really notice it during the first 2-3 layers using a translucent red PLA (Ingeo 4048D based) and you could see from the color changes from dark to lighter and back to dark synchronized to the clicking of the relay leaving a 45 degree 'zebra stripes' pattern on the print. It wasn't noticeable that much in the finished print but it was definitely a clue heat regulation sucked and there was constant expansion and contraction going on but the SSR and PID control cleared that up. I kind of figured going in that I wasn't going to like the bang-bang controlled bed

An aluminum bed and a good silicon heater are a better solution whether you use ABL or not ...... but it also adds costs and weight. This works for me, I'm happy with it for now. Granted what works on a 10 may not work on a 12", I opted for the 10 because 12" bed at only 12v is really pushing the limits