Loadcell

A loadcell is a component that converts force or weight into an electrical signal. 

On our printers, it is part of the Nextruder, equipped on our Prusa CORE One, and Original Prusa XL, MK4/S, MK3.9/S. It detects if the nozzle is close enough to the steel sheet for printing. 

A printer equipped with a loadcell has a first layer set automatically during the mesh bed leveling. This avoids any damage that would be caused by the nozzle digging into the steel sheet.