Following extruder in Z axis of Original Prusa i3 MK2 MMU

thingiverse

Original Prusa i3 MK2 MMU It's the third iteration of Following extruder for MMU. Printing a large model takes over 18+ hours. I experienced multiple printing failures of large models whose height exceeds 180 mm. The cause of failure is excessive friction when the PTFE tube forms tighter curves as the hotend assembly moves up to maximum height. The weight of two extruder assemblies is about 637g to 639g. To reduce the weight of two extruders and 2020 aluminum extrusions on Z axis stepper motors, I use a counterweight system composed of two weights, two pulleys on left and right sides. I plan to replace the vertical motion system on Z axis - M8 hardened steel rods, four M8 linear bearings - with linear rails.