This is a filament feed tube holder that mounts to the Taz 4-5 carriage. I was snapping some brittle filament at times as the carriage moved back and forth. The weak point was where the feed tube just lays against the top of the idler arm forming a fulcrum point which may snap some filaments like Laybrick for example.
This holder mounts to the extruder mount plate and accepts the end of the feed tube. It will flex slightly as the carriage moves but it will hold the tube more or less vertical forcing the tube to bend instead. This spreads the load out along the feed tube thus reducing any small hinge points.
It has a split retainer ring so filament and tube are easily removed without having to thread it through the holder or remove the holder at any time.
You will need a M3x16 screw to replace the M3x12 that the Taz currently uses to hold the extruder plate onto the carriage. The current screw is simply too short. No other modifications are needed.
The tube holder is sized to fit the feed tube that came with my Taz 5. It is slightly oversized at the top to make it easier to insert the tube. If you are using a feed tube with a different diameter, you will need to either drill the holder out or edit the mesh to enlarge the internal diameter. I made sure the polys are clean so resizing in a mesh editor should be fairly easy.
5/1/15 - Added 3 additional file types for download.
It is designed to print 90 degrees from the way the STL has it. I left it vertical so you could see the split ring. It should lay flat to print.
I printed mine in ABS at 0.2mm layers, 25% infill, 4 perimeters and 4 top/bottom layers. That should give it the stiffness to hold well but still allow some flex in the arm.