this is a litle circuit that i found on ebay. china it normaly has a light dark sensor that conviniantly has the same resistance as a fsr (force sensing resistor) and still is controlable with the potentiameter that means you just putt the sensor between the carriage for your extruder end the extruder itself and then you dial in the force so at the smallest amount off pressure the fsr will tby brunoschoofs - General
I had the same problem after i moved from sprinter to marlin butt in the other direction I did not alterd the speed butt deleted the z axis 5down move that seemd to do the trick toby brunoschoofs - General
mine is jamming to randomly and i use the same solution I also want something else as a solution I think in slic3r you can choose wat suites you the thing you alter when you alter the layer hight is just that it makes smaller hight layers so that your print is more precize I drew some things to benefit my printer and you should realy take in consideration making you height and thickness accorby brunoschoofs - Printing