The optical approach should produce a response, especially if you put white paper down on the bed. Don't know if accuracy and repeatability are acceptable...
Seems like the force resistor could be put at the arm/ carriage interface. Or maybe the carriage/belt connection. Run the hot end down to the bed. When it touches, the weight comes off the arm and the force resistor sees it.
Post by bvandiepenbos on Jun 9, 2014 16:47:45 GMT -5
I ordered 3 force sensing resistors to try putting under bed to senses when nozzle touches build surface. Not sure how just yet, probably increase size of 3 of the mounting ears of the snowflake bed insulator and sandwich resistors there with only light pressure on the mounting screws. The other 3 bed mounting screws might need something with a bit of spring or squish, like a wavy spring washer. cork maybe?