heatbed and bed leveling

Congrats Jerry RoBo 3D on the move to your own boards. Should be pretty nice.

 

OK - A slight need to correct my upgrade suggestion - Get the better fuse and you find a better Mosfet or keep the stock. My argument of my choice for Mosfet was not accurate (my ignorance.) and a better choice should be found with a low gate threshold <<1.7V and low RDSon <<0.016 Ohms. So - theoretically (actual?) my fix is working more for the 15A fuse than combined with the stp80nf55-08 Mosfet. But, the RAMPS components for the heated bed are cooler and the bed has been @ 110C for several hours with PID running quite well. Whereas it wouldn't get to 80-90C before.

See:
- https://github.com/ErikZalm/Marlin/issues/688#issuecomment-34272834
- http://forums.robo3dprinter.com/ind...ddition-to-prevent-heat-bed-cutting-out.1299/