Toi clarify i was meaning a stanley knife or simular, they have a fixed or snap off blade that slides in and out with a knob or lever on the knife body, slipped all the way back theres no knife, pushed out one click you have a small blade come out the end, the farther you push the knob the more the blade comes out, i
Instead of the blade you can use a pivot point and on the knife caseing you fasten a pick, this would mean you can slide a pivot point under the pick to stop in any position.
Im sure you realised this and its me getting the knife type wrong,
Cant wait for the pics and results
