Xtreme Radius PTFE Tube Splitter

I found that most PTFE splitter models available use S-shaped and/or tight radius curves.  These work fine for normal unfilled filaments, but I print a lot of glass fiber nylon and I've found that those designs cause a lot of problematic binding/friction.

My design uses filament paths with a radius of 250mm, which will allow even the most rigid fiber-filled filament to pass through easily.  I have printed many kg of glass fiber nylon and even a little carbon fiber PC through this with zero issues.  My design also uses a polygonal filament path, which makes it easier for the slicer to print accurately-sized holes and gives sharp internal corners to place the seam.

There are two versions:

1. All ports threaded for pass-through push-connect tube fittings.
2. One of the inlet-side ports is unthreaded for a slip-fit with a PTFE tube (this works well when printing from a drybox, where you don't need the end of the PTFE tube fixed in place).

Note: The threads are sized for 1/8 BSPP (ISO) fittings, although they will likely also work with 1/8 BSPT and what a lot of fitting vendors refer to as “M10x0.9” (which, as far as I can tell, is a pretend designation for 1/8 BSP, but people are allergic to fractions, so…).  They may also work with 1/8 NPT fittings, although the pitch is slightly different.

An example of the type of fitting that will work: https://amzn.to/3Q04Cpa

These are sized for 1.75mm filament and 4mm OD tube.

The horizontal lines on the outside of the part indicate how far the PTFE tube should freely insert.

Print settings:

• Model should be upright, with the single outlet port on the build plate.
• Layer height .12 or smaller (0.08 works well).
• 3+ walls @ .45 width (.4 nozzle).
• 15-30% infill
• Enough top and bottom layers to be about 1 mm thick.
• I use Arachne, but Classic may also work.
• You may need to tweak your X-Y hole compensation until the PTFE tube fits snugly.  You shouldn't have to force the tube in, but it shouldn't be loose, either.