Caulking cartridge cutter

Update 30-3-26: optimized some dimensions to make the cut a bit deeper. (The caulking tubes differ slightly between manufactures),

What is a painter without his trusty caulking gun, for sealing windows, for hiding cracks in the corners and walls, etc. 
To open silicone caulking cartridges most people use a utility knife. But you have to be a bit careful (besides not cutting in your thumb ): if you cut to much of the tip off, the nozzle won't stay on and things become messy. 
To always have the perfect cut, I present you the most over-engineered way to wield a 20mm stainless steel blade 😊.

Just push on the tip, squeeze and turn. And to store it away for the next time, just put it on the end of a cartridge.

Printing
I printed in Prusa PLA, 0.2mm layer height with 0.4 nozzle, speed profile.
Turn the lid upside down on the bed.
If you don't need the helper disks, remove them. Put snug support under the knife holder part and the two overhangs on the housing.
After slicing, insert a print pause at 8.8mm to insert the knife.

For the knifes, use the small 9mm Olfa, Stanley etc. snapp-off blades. Snap off 4 sections (20mm), or use the end (with the hole) of an old blade.

After printing, clean up the parts, slide them toghether and glue the lid on.

Enjoy!

Bart