A Simple Bowden Tube Guidewire Fix

thingiverse

After swapping out my BOWDEN tube on the X5S printer, I noticed it was flopping back and forth excessively. I also experienced random under-extrusion throughout prints, accompanied by 'ground filament' accumulating around the extruder gear. I tried increasing the extruder current and running multiple extruder calibrations to resolve these issues, but it wasn't until I realized that my BOWDEN tube would sometimes take on a sharp bend near the output of the extruder that things clicked into place. It turned out that an overly tight bend in the BOWDEN tube was causing filament to bind up inside the tube, leading to all the above symptoms. To combat 'Floppy Bowden Tube Syndrome,' I designed a simple piano-wire guide-line and bowden-tube-clips to keep my BOWDEN tube moving smoothly across the XY stage. Although I created these parts for my TRONXY X5S printer, they should be adaptable to any machine with a BOWDEN tube. All that's required for this upgrade is two 3D printed part designs and a length of piano-wire, approximately the same length as the BOWDEN tube itself. One of these printed parts (two units required) clips around each of the 10MM hex nuts that make up the tube fittings on the extruder and hot-end. These provide an anchor point for each end of the piano wire - I used .05 in diameter steel piano wire from ACE hardware store in the U.S. The second printed part is a simple clip (four to eight units required) that snaps onto the BOWDEN tube itself, featuring a small hole that feeds onto the guide-wire. A few of these should be printed and placed along the length of the BOWDEN tube to link it to the guide wire. You can slide them along the length of the guide wire to find the best placement for each one, ensuring no tight radius bends in the tube occur as the XY head moves through its total range. Then, as the hot end moves in X & Y, the wire guides the motion of the BOWDEN tube in a way that prevents any tight bends from occurring.