MK3 quick screw-on reverse bowden + connectors

A compact, fully 3d-printed reverse bowden setup compatible with the MK3 or the MK3 Bondtech extruder upgrade.

The bowden attachment is optional and can be quickly screwed-on when required. Fits regular 4mm bowden tubing. Includes a female-female bowden connector for further splicing.

The cover is actually smaller than the original MK3 sensor cover, and requires shortening the internal PTFE tube to a length of 12mm (remember to redo the internal 45 degree internal chamfer after cutting).

The screw and connector require a tight fit on the bowden tube in order to work correctly. The screw includes internal notches to hold onto the tube which require a decent amount of force to overcome. Once fitted though the screw can be rotated while holding the tube stationary.

Due to the bowden tolerances, and to get the right fit, the assembly comes in three variants: tight, medium and large. To find the right tolerance print the connector piece: the bowden tube should require some light pressure to insert and remove. The connector shouldn’t disconnect by itself or by simple shaking.

STEP files included if further adjustment is required!

Printing

• Sensor cover can be printed with either 0.15 or 0.2mm layer height, 0.4 nozzle.
• Screw and connectors require 0.15mm layer height, 0.4 nozzle.

Using other settings might compromise the tightness of the screw and fit of the bowden tube.