Knifemaking is one of my favourite hobby. I often read some posts on this forum without daring to post. But today I have a problem with a linerlock. I have changed my usual design and have a problem with the spring which is too soft. I think that the length of the spring is too long and the blade doesn't hold securely in the handle when closed if I shake the knife. Also the blade don't snap correctly and has some small play when closed. The detent ball stays in the blade's divot nicely and the spring follows the same small play as the blade when closed. :punchself .
Hope it's clear enough !!
Do you have some ideas to correct that problem other than redo the liner.?
Liners are Ti 1.5mm thick (0.06 inch).

Thanks in advance for your answers.

Jean-Yves

There is plenty of opportunity here for me to misinterpret what you are describing so, if I don't understand correctly, please just ignore what I am about to say.

If your liners are .060 in thickness then they are thick enough for any normal sized knife. The lock could be cut too long as you suggested but I would tend to think the width is more of a problem than the length, i.e., the lock bar needs to be wider if it is to be cut that long.

Your description seems to center on concerns about the play when the blade is closed. You also state that the ball seems to be perfectly centered in the detent. That's a problem in most cases. A perfectly centered ball will allow a little wiggle room . A better situation is to have the ball about .020 (assuming a .062 ball) off center from the hole so that the ball fails to reach the center of the detent by that amount when the blade is fully closed. This causes the ball to pull on the blade constantly, so no slop is possible.

I'm afraid that doesn't solve your problem though, unless you either make a new liner or install the ball in a new hole in the lock bar and drill a new detent in the blade, if that's possible...

Thank you Ray. Your analysis is the right one. The width of the lok bar is more important than the length in my case. I have to make another liner :banghead . The problem will be to drill the hole in the new lock bar at the right position to have these 0.02 off center of the hole in the blade which is already existing.

Jean-Yves

You might consider putting the ball further up or down the face of the lock bar so that is at least 1 ball diameter away from the former location. This would allow you to place a new detent in the blade....

You could also try a larger detent. Some people don't like to use the larger balls, but if you are going to make a new liner where's the harm in trying.

Jeremy

A larger ball occured to me too but I decided against it. The larger the ball, the thicker the washers generally end up being. If he really works at it and drives the ball all the way through the liner so that it is no taller than the smaller ball, and then grinds it flat on the back of the lock bar, it might work. But, then the larger ball won't go into the smaller detent very much and won't be able to hold the blade very firmly (although it could fix the 'wiggle' problem).

All the above is on the assumption that his washers are thin. If they happen to be thick then a larger ball is a marginally more attractive option ....

What size hole are drilling into the blade for the detent. When I first began making folders, I had this same problem with a loose fit though the detent was centered. By reducing the diameter of the detent, it allowed the knife to close more positively.

I've been in auto pilot that I don't recall what size bearing, the detent hole is a #55 and is not depth critical since the bearing will fall into the outer ridge of the hole.