This is a from-scratch redesign of "PTFE/Bowden Tube Passthrough with GE4C Spherical Bearing" by Mark Norris. It retains the same footprint and hole spacing for full compatibility while introducing key improvements.
- Full Range of Motion The passthrough is designed for a 12 mm hole in a 3 mm thick panel, ensuring that the GE4C spherical bearing's center of rotation is precisely aligned between the inside and outside surfaces. This maximizes the bearing's range of motion.
- Minimalist Exterior The top half features heat-set inserts for M3 screws, ensuring the outside remains smooth with no exposed holes.
- Minimal Interior Profile The bottom half is only 3 mm thick, keeping it as compact as possible to minimize interference with the Bowden tube inside the enclosure. The other half is slightly thicker to accommodate the heat-set inserts.
- Smooth Filament Path The edges around the bearing hole are gradually sloped, preventing the Bowden tube from catching or kinking when moving against the printed surface.
- 1x GE4C bearing (i.e. 12x3 mm outer ring dimensions)
- 2x M3x8 mm FHCS (but M3x10 mm FHCS should fit too)
- 2x M3x5x4 mm Heat-set Insert
I recommend printing with standard Voron settings, but variable layer height improves curved surface finish if your slicer supports it. A lower infill density may also work.
- Layer height: 0.2mm
- Extrusion width: 0.4mm, forced
- Infill percentage: 40%
- Infill type: grid, gyroid, honeycomb, triangle, or cubic
- Wall count: 4
- Solid top/bottom layers: 5
- Supports: none
- The halves are not symmetrical — be sure to orient them correctly when assembling.
- I recommend making a small pilot hole using the drill template, then using a stepped drill bit to gradually widen it to 12 mm for the best fit.
- A bearing press-fit is optional since the printed halves will secure the bearing, but minimizing lateral play is still recommended.