Titan adaptor for using 3mm ID reverse-Bowden tube

thingiverse

This adapter serves as a primary tool for utilizing 4mm OD/3mm ID PTFE tubing in a reverse bowden setup at the input of a Titan extruder. To mitigate issues with filament spilling off nearly-full spools and achieve cleaner prints, I employ a reverse-bowden arrangement to prevent irregular jerking of filament from the spool due to nozzle movement. A diagram illustrating this setup is included for reference. Typically, 4mm OD/2mm ID PTFE tube suffices for this purpose; however, using a 3mm ID tube simplifies threading the filament through long tubes and reduces frictional drag during printing. Nevertheless, a 3mm ID tube fails to control the feed position of the filament into the Titan extruder gear effectively, which can lead to drive problems at times. This adapter features a ~2mm opening to maintain the filament centered within the gear. PTFE tubing is inserted into the adapter, which can be optionally secured using a narrow 4" nylon cable tie. The other end of the adapter is then inserted into the Titan extruder where PTFE tube would typically go to feed into the drive gear. The tapered design of the adapter facilitates easier insertion or removal from the Titan, simplifying filament loading and "atomic pull" nozzle cleaning processes. This adapter can be used with a standard 2mm ID PTFE tube at its input if only those benefits are desired. To minimize inside friction, print this part using a 0.4mm nozzle and 0.2mm layer height. The printing process takes approximately 10 minutes due to the small size of the part. Two STL files are provided: one straight and one with a 25 degree bend. Choose the file that best aligns with how your PTFE tube is configured.