Bowden Tube Clip

thingiverse

Update 12/21/2016: Uploaded the FreeCAD file. My Cobblebot features a large print area and the bowden tube is about 3' long to accommodate this size. With the twist that comes from the tubing being coiled during shipping and the twisting caused by the filament it would create too much back pressure and my extruder couldn't push the filament through the hotend. Picking up the tube and holding in "straight" would alleviate the problem. While the tube could be shorter, I like the smoother radius of a longer tube to minimize back pressure on the extruder. If you use a tube that's just long enough to cover your bed area, it will increase the work on the steppers, which need to overcome the resistance of the tubing as it bends. I also saw twisting/bending in much shorter tubes causing high resistance to the extruder drive. I designed this clip to align the Bowden tube using a large (in this case 36") tie wrap as a support. Originally, I tied-wrapped the tubing to the larger one, but that was a pain to remove when I had a plugged extruder or needed to do other work. The before picture of my tube shows it straighter than it was before this solution. It has been tied down to the large tie-wrap for a couple weeks and is still holding its shape. This design is specifically tailored for thinner tie-wraps, less than 2mm thick. Thicker Thomas and Betts (T&B) tie-wraps won't work because they are significantly thicker. Additionally, make sure to buy tie-wraps that come packaged without coiling - the coil will remain in the plastic and won't be an effective support. I created this clip using OpenSCAD but the code is messy so I didn't include it. Lots of trial and error went into making a clip that would fit properly. Update: This design was made for 4mm diameter tubing, and the large tie-wrap has a cross-section of 2mm x 8mm. Print Settings: Printer: Cobblebot Basic Rafts: No Supports: No Resolution: 0.2 Infill: 70% Notes: The clip likely doesn't need this high level of infill, but I wanted it to hold when snapping onto the tubing. Six clips should be sufficient for shorter tubing.