Hi again folks !
Could anybody clear this up : are these kind of heated bed ("Mk3 pcb aluminium heated bed’, see attached link) fit to be used together with inductive proximity sensors ?
Also , very important, I intend either to use a glass on top, or nothing at all (never going back to kapton /and or painter’s tape) , so given the short sensing distance of inductive sensors, not quite sure this would work?
Thanks again in advance !
Looks like it’d work, but 3mm is a bit thin. Might warp as it heats.
I have a MK3 Heatbed. There is no warping.
and I know from others that the inductive sensor works.
Thanks a lot for the replies !
@Hakan_Evirgen & @Rob_Barnard great , thanks for the infos!
@Rob_Barnard are you also using with a glass bed ?
I’ve just received one – and I must say I am impressed: beautiful, heavy and well done!
careful when buying. http://reprap.org/wiki/PCB_Heatbed
"WARNING!!! Be aware from where you buy the PCB heatbeds!! There is one critical thing, the heatbed must be etched directly from 35um copper clad! ASK YOUR SELLER!!! If the board is plated, as it’s normally done, no manufacturer can guarantee the final thickness of copper or how even the copper is around the board. Which means that the final power won’t be evenly distributed around the board or the board won’t have a high enough heat output generally.
Main warning sign are plated holes! Plating of holes requires copper plating.
@Hakan_Evirgen thanks for the warning, I will double check when I can. A FLIR camera would make sure if it is even. Anyhow, I was curious anyway to know what it looked like and how it was done. The PCB traces definitely are plated (but they are quite wide).
Now if it fails, well, I have an expensive 3m alu board to add a regular PCB underneath! 
@Jeremie_Francois other way is: get a aluminium plate, get a silicon mat heater. The advantage: if you the heater for mains power together with an SSR to switch it, your heat up times will be drastically reduced. I made that on my delta printer as it needed more than 10 minutes to heat up for ABS. now it needs about 1 minute.
actually my electronics failed because of the heating and that made me to change it 
