Liner lock notch?

[Ray Murski]

I have a few questions about the design of the liner lock notch.
1. The notch angle on the blade that engages the liner for lock up. What angle do you prefer?
2. How does the distance of the notch from the pivot effect the performance of the knife?
3. How big should the notch be? How does a smaller or bigger notch effect the lock up of the blade?
4. What determines the minimum and maximum thickness of the blade stock?
5. What other aspects or dimensions of the notch do you consider important when designing a liner lock knife.

 

[tom mayo]

hi ray...the thickness of the blade is irrelevant......the angle is super important, 7.5 degrees is optimum, you can vary about .5 degrees either way, but too much angle will make the lock slip and too little will make it stick closed. do Not make the lock go above the center line of the blade pivot......I make the portion behind the pivot just a tad longer than the washers i use, which i think are .5" across. longer just makes your handle long because you have to hide it inside the front of your handle....one thing that is crucial, very crucial, and you will have to play with it to get it right, is to make sure the ball bearing in your liner stays on the blade tang thruout the closing arc....put a small dot with a magic marker where you think it should go and operate the blade and you will see what i mean...the farther down the lock you put the ball the sooner it will engage the tang when you are closing it, that is the quicker the lock will go up onto the blade, and the farther up, close to the corner, the later, after you have made a few dozen youwill start worrying about this, make sure you inset the ball at least 2/3 of its depth into the liner or it will be hard to open......and make the hole in the blade smaller than the ball diameter.....so it wont wiggle when its closed....I understand wayne goddard has just written a book which outlines a lot of this stuff....

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http://www.mayoknives.com

 

[tom mayo]

post script...meant to put it above. make sure to use ti 6/4 that is plenty thick.. 040 or 045 minimum for a stiff lock...the thinner stuff can be bent when pushing down on the blade in the open position....

 

[Darrel Ralph]

IMHO 6 degrees for some purposes (total lock up) folding swords ect..
7-8.5 degrees for standard every day use . This dependes on the material used and the thickness of the liner.
For autos 10-12 degrees . Autos have a lash back that causes the liner to stick more. More angle is required to release them sometimes.

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Web Site At www.darrelralph.com