I just came across this thread and have been working on making an automatic bed leveling system that works on my home brew delta printer running Repetier. I started with an FSR on one of the delta towers between the carriage and the belt drive but moved on due to concerns about adding mass to the moving parts and difficulty getting consistent readings. Next, tried load beam sensors under the bed with an HX711 chip. That turned out to be way too slow to be practical (almost a 10th of a second to get a reading from the HX711). Have now moved to FSRs under the bed with a few modifications to the Repetier code and am getting appropriate high/low values when sending G31. I only had 2 FSRs so will need to take delivery of the third one before completing the actual test, should arrive this week. I'd be happy to share what steps were required to get it working if you haven't found the solution first.
theFabFor