"Slignose" PTFE inner chamfer tool

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I wanted to cut internal chamfers on my tubes. Inspired by a simple yet effective design by Big E for external chamfers, I designed this one for internal chamfers.

Now - unlike external ones, this is quite sensitive to the exact blade size. I used a 23mm x 6.4mm blade, salvaged from some cheap pencil sharpeners from a local store. So if you can't find one that matches at least the width (length is less necessary to match as the model has provision for adjusting that) you may need to edit the model, or simply glue the blade into place. FreeCAD file included.

But for me, using that blade? It works damn well.

Instructions:
- Print in your preferred material (any rigid material should be fine). No supports or special settings are necessary.
- Attach the pencil sharpener blade. You ideally want the sharp corner of the blade to be exactly in the middle of the tube hole.
- Insert PTFE tube from the rear
- Apply pressure and rotate slowly a few times
- Continue rotating while slowly withdrawing the tube until it is clear of the blade
- Run some filament through the tube by hand from the other end a few times to clear out any PTFE specks that may be left behind (shaking the tube can also help dislodge these)

And if you're wondering about the name? While designing it, at one stage I felt that it reminded me of the nose of sligs from Oddworld.