I am having trouble with the locks on my first two linerlocks. They lockup well and I can't make them fail by appling pressure by hand, but when I smack the back of the blade on the workbench they fail. My question is what is a goood lockup? should it never fail with a smack on the workbench?
The construction of the knives is as follows
1. I used one of don Robinson's templates for the lock geometry
2. .050 ti liner and spring
3. Lock face is ground at 9 degrees
4. The spring is bent to the opposite liner
5. Outside edge of lock sits approximately even with the outside edge on lockface

Thanks in advance foer any advice

Steve Pattersion

5. Outside edge of lock sits approximately even with the outside edge on lockface

If you mean the lock sits at the beginning of the lock face then I would adjust it to sit more towards the middle of the lock face. To do this, I prefer to remove a little bit of metal at the back of the blade where it contacts the stop bar. I find this method to be a little more forgiving than trying to alter the face of the lock or the lock bar.

When you get it right, the blade will not close no matter how hard you strike it on the back ....

Steve, if I understand correctly your lock spring sits flush with the outside edge if the blade.

If that's correct, then tell us something about the contact.

First off, 10 degrees on the blade lock face is about as much angle as you can use without having the lock bar slide right past the blade.

1. How long is the lock bar?

2. Do you have an angle on the face of the lock bar?

3. how much contact area do you have on the lock face with the bar? Does it pretty well match the lock face vertically looking at the bottom side of the handle?

Ray, sorry to butt in, but the way I read his post is that the bar is in the right position.

Thanks Ray and Don

The answers to Don's questons are as follows

1. The lockface is ground at 9 degrees

2. Lockbar is about 2 3/4"

3. Lockbar is close to the same angle as the lock face

4. Contact area is about .125"

You;re not butting in Don. Problems like this one are difficult for people to describe accurately so the more answers he gets the better chance that one of them will *click* for the po' boy .........

Thanks Ray and Don

The answers to Don's questons are as follows

1. The lockface is ground at 9 degrees

2. Lockbar is about 2 3/4"

3. Lockbar is close to the same angle as the lock face

4. Contact area is about .125"

1. I suggest using 7 or 8 degrees.

2. That should be OK if it's a very large knife. Too long for smaller knives. The longer the bar, the weaker it is.

What thickness are the liners, and are they made of titanium?

3. The lockbar should be square. If you put the same angle on the bar you have on the blade, when the bar swings over in its arc the angles won't match at all. Only the outside edge of the bar will touch the blade, and it may slide right off.

4. In my opinion you should have made the contact area larger, but if the bar and blade lock areas are correct, then 1/8" should work.

Hope this helps. If not, ask away.:D

Ray, whatcha thinkabout this?

I just re-read Spatters' post. The liners are .050", so that's fine.

Looks like the problem may be caused by having an angle on the lock bar and that the lock bar is too long for .050 Ti. It's also evidently only 1/8 wide, which weakens it even more.

One important thing to add:

Don't ever bend the spring all the way over to meet the opposite liner. That torques the whole assembly too much and can actually put a bend in the handle if it's too severe a bend. The 1/8 bar probably is too weak though for this to matter.

Spatters, please don't be put off by this critique. I wish I had had someone this handy to help me when I started. But that was back when there were no knife forums. :rolleyes:

Back when knives were made from stone Don ?:lol

Dave

P.S. I best hush I just started a new folder and will need to ask questions soon Im sure. hehe

Welll,,, later than that.:D

We did have bronze.:p

Thanks for all the info

The knife has a 3 1/2 inch blade and is 7" overall. What would you suggest for a lock bar length with the .050 titanium.

Steve

Steve, I'd use a 1 3/4" long lockbar with .050" ti.

Make the engagement end about 1/4" or so wide and the width at the bend area should be around 3/16". If the bend width is wider, just drill a hole at the end to make the remaining wall over to the edge about 3/16".

This is what works best for me. Others probably have different ways.
Springs that are too long or too thin can be be sprung open by shocking the lock. :eek:

Steve, the way you describe your knife sounds like it works just fine until you whack the spine of the blade against something hard.

In use, you'd not do that, so what's wrong with it the way it is now? Use it and our advise and change the next one.:)

And the next one....,,, and the next.....;)

You're hooked on folders now, and you will always strive to improve the next one. And the next,, etc. to infinity.

But that beats watching TV, doesn't it Ray?:)

"But that beats watching TV, doesn't it Ray?"

It's hard to say with certainty Don since there is no tv or radio (no cell phones either) reception up here in the mountains where I live. I spend all day, every day, making knives, reading and writing about knives, and talking knives and it seems a good way to spend my life so I think you must be right about that....

Thanks for all the help

I think I get the idea now. I have another set of liners made and a blade balnk. I'm going
to set it up with the shorter lockbar and more contact with the face.

Thanks Again

Steve