Mk9 / Mk10 Extruder - Precision Feeder, reliable flex filament prints

thingiverse

When printing TPU on my Maker Select V2, the filament inevitably jams after a few minutes by wrapping itself around the extruder motor gear, even at 10mm/s. To ensure reliable TPU printing with the Mk9 extruder, I designed a new frame/housing/feeder with reduced open space around the extruder gear and guide wheel below where the filament is fed/pushed. The gap is too small for the filament to bunch up into, so it goes down and out of the nozzle instead. There's still a slight bevel on the guide entrance to improve ease of filament changes. It recently finished a ~1-hour print at 40mm/s and 0.1mm layer height, making it a success. I used support only for the cutout on the build plate for the circular bump surrounding the motor shaft. The support was easily removed using the tool that came with the printer and just a few seconds of prying. Here are the Cura 3.2.1 settings I sliced it with, printed in PLA: adhesion_type = raft layer_height = 0.1 layer_height_0 = 0.2 material_bed_temperature = 60 retraction_combing = all speed_slowdown_layers = 5 support_enable = True support_type = buildplate alternate_extra_perimeter = True default_material_print_temperature = 215 fill_outline_gaps = True gradual_infill_step_height = 0.8 gradual_infill_steps = 1 infill_pattern = cubic infill_sparse_density = 40 layer_0_z_overlap = 0.2 line_width = machine_nozzle_size material_print_temperature = 215 optimize_wall_printing_order = True raft_airgap = 0.2 raft_base_speed = 10 raft_base_thickness = 0.2 raft_interface_speed = 20.0 raft_interface_thickness = 0.2 raft_margin = 5 raft_surface_line_spacing = 0.4 raft_surface_speed = 40.0 raft_surface_thickness = 0.2 retraction_amount = 6 retraction_speed = 40 skirt_brim_minimal_length = 400 skirt_gap = 7 speed_infill = 40 speed_layer_0 = 10 speed_print = 40 speed_topbottom = 40 speed_travel = 40 speed_travel_layer_0 = 40.0 speed_wall = 40 speed_wall_x = 40 support_infill_rate = 20 support_line_width = line_width support_pattern = grid support_xy_distance = 1.5 support_xy_distance_overhang = 0.4 support_z_distance = 0.2 top_bottom_thickness = 1.2 wall_thickness = 1.2 xy_offset =