"Tri-Fold" gravity knife, utility knife

This is a gravity knife with a unique mechanism inspired by Fred Perrin Tri-Fold knife AKA Jacob's ladder knife

 

The knife holds standard utility blades, which are easily swapable.

 

I suggest using the included training blade until you learn the mechanism. Dont hurt yourself!

The knife might need a little breaking in if it feels tight. deburring and a little lube might help!

 

Assembly:

 

Correct blade dimensions (standard trapezoid blade):

 

 

 

 

Check out my other gravity knife model!
"Dragonfly" Gravity knife

 

Boost MeIf you enjoy the model, consider boosting :)

*** Update 13.2.2026

Modified the blade seating slightly

→ blade seated more securely

***