PTFE Chamfer Cutter for Prusa Mini

If you have a Prusa Mini then you probably will experience the short PTFE tube that goes into the heatbreak shrinking and need to replace it with the spare that comes with your Mini. And then that will shrink and you will need to cut your own, but the 120 degree chamfer is hard to cut so I made this tool to make it a lot easier.

The newer version comes in three versions and includes a cutting jig, make sure you select the one that includes the right length for your PTFE tube:

• Standard Prusa Heatbreak version
• Bondtech Heatbreak version
• Bondtech Heatbreak longer version (I find this works better for me as it fits inside the nut)

You will need to add a standard single edge blade (it's these) which you probably have lots of if you are one of the three people who used my Cupcake Filament Cutter, and screw it to the block with 2x M2 8mm bolts.

I have included a Step file and the original Fusion 360 files, just in case. If you adjust the cutting jig you will probably have to redo the chamfer and fillets.

To operate, push in a PTFE tube until it hits the end stop, and turn the tube clockwise (or the block anti-clockwise) a few rotations and stop pushing for a rotation or two until it's cut.

Once you have a nice chamfer, insert the tube into the cutting jig.

Then using a blade (BE CAREFUL) cut the tube through the slot provided.

Then use the hole and your nail, or a screwdriver, or maybe even the blade if you are desperate (BUT BE CAREFUL) to eject the tube using the window.

Printing

Prints without supports, PLA is just fine, 0.20 layer height is ideal, just choose a nice colour now!