PTFE-tube 60° chamfer tool by printschnitzel.at

Printed at 100% size, Prusament ASA, 0.6mm nozzle, 0.15 layer height.

Works great but the assembly is a pain.

You'll need an Allen key (imbus) for the m3 screws, since a screwdriver won't fit.

Initially I printed at 103% as recommended by a number of the comments, but then the side screw wouldn't properly thread into the plastic.

Assembly since this isn't so straightforward:
1. Print all parts, using the pause from the modified gcode to insert the blade (single chunk of a 9mm blade) into the indent on the small part (align blunt side with the back wall, sharp side goes out).
2. Clean up the parts (file/sand) since this is a tight fit.
2. Make sure the slot in the blade part is cleaned up and push a square M3 nut into it. Use some force if needed to make sure the hole in the nut is relatively well aligned with the hole in the plastic.
2. Slide the blade part into the hole in the body, blade pointing downward. Push the part in so it aligns with the bottom of the bigger hole. File the blade part more if it doesn't go in, but you'll need a bit of force either way.
3. Screw in the longer screw into the blade part from the top just deep enough so that the head of the screw is between the wings in the hole. (The third part will be inserted sideways later so the screw head needs to be in the right spot).
4. Grab the third part and the Allen key and make sure it can go all the way through the small hole in the part If not, just force the key in and hand-drill the hole using the key.
5. Push the third part into the hole on the body sideways (do more filing if needed). The screw head should end up in the slot.
6. Grab a piece of PTFE tube and try twisting it into the hole. Adjust the depth of the blade using the top screw (through the small hole) until the blade starts cutting the chamfer into the tube.
7. Screw in the shorter screw into the side hole to secure the blade in place.
8. You're finished.

The tolerances were a bit tight for me and I had some difficulty getting the blade to sit flush in the paused print, but in the end I got it to work. I didn't see any instructions on how far to seat the blade into it, so I had to do some trial and error to find the depth that would create a good chamfer while not cutting the PTFE tube into a spiral ribbon (which is what happens when the blade is pushed in too far. I tried to include a picture of where I ended up finding a good depth to give other people an idea of where to start!

It's a bit finicky to get the blade in and have the rest of the guide print just right, but it works overall and appears to get the job done.

Thanks! Printed in PETG

Well thought out design. print it at 103% though. it'll be way easier to work

Neat idea but all it did was murder my PTFE tubes :(

This is a pretty great tool once you get it adjusted well. I did open the step file in fusion and made it so I could use a heat insert for the side threads. I also sized it to 103% when printing. Getting the generic blade I had on hand also required some tweaks to the step file and the wall type setting is important as well. For me it was better setting walls as arachne. A touch or two with sandpaper helped to get the cutter part to fit just right. I also took a 4mm reamer to the insert hole so I didn't have to fight the tubing to get it in. Some are getting the assembly wrong or I am... The top adjustment bolt should have the head inside you should access it thru the hole. It shouldn't be showing outside of the print.

Works as intended even fit is a bit tight and required just a little bit of force, maybe sanding

Awesome design! Thanks a lot for sharing.

Printed with 103% scale like other suggested.
Still tight fit, but works.
I struggle with the assembly and why i need the screws.

another great gadget, a must have!