Optimal position of the liner lock

[alan0354]

Unfortunately not.

I would recommend purchasing R. Terzoula’s book:

The Tactical Folding Knife: A Study of the Anatomy and Construction of the Liner-Locked Folder​

Hi, thanks for the suggestion, I checked, it's very expensive and I think this is quite simple to design. I gave it some thought and this is what I come up and I want to get your opinion:



To ensure longevity, I decided to only file the liner so it barely goes deeper than the left surface of the bottom of the blade as show in the picture on the left. So it still have a long way to wear to get to the right side.

The most important thing I did is to bend the liner lock out so it put more pressure towards the right side so it make it harder to being push to the left. To me, from talking here, that's the MOST IMPORTANT thing or safety and reliability. Of cause this will make it hard to open.

To solve the problem of hard to open because of the extra pressure towards the right, I use a diamond bit to flare out the Detent hole on the blade where the Detent ball on the liner fit into. That really make it easy to open, NO DIFFERENT from the original knife.

My question is what is your opinion on the angle to grind on the liner lock shown in (B), (C) and (D) in the drawing. I pick (C) so it's not to steep angle like (D) where it wear out faster.

Let me know your opinion and what advice you have.

Thanks

Alan

PS: The knife is Steel Will with bronze washers, no ball bearing. So there is very little gap between the metal liners and the blade. So even if the liner lock wear so it goes all the way to the right, it will be stopped by the metal liner on the right to prevent it from moving pass the bottom of the blade. I actually screwed up one and grind the liner short enough and travel all the way to the right and I actually feel it is quite secure, no free play on the blade, it won't wear out any further as it is rested against the right liner.

I really don't care about the ease of closing the knife, the most important to me is ONE HAND FAST DEPLOY for self defense. I can take my time to close the knife.

to me, the knife is for self defense, it has to have long flipper tap so after it deployed, it will serve as safeguard to prevent the knife from being shoved back to my hand when I thrust and hit hard object. To me that is the UTMOST IMPORTANT FEATURE. There is no other way to protect the hand. A lot of nice looking knives are very stream line and pretty, they don't put the tap and it's useless to me.

 

[Greggy]

The slope of the tang landing pad allows for wear. It is a self-adjusting mechanism. Hence, why late lockup (the leftward sample in your pic) is inferior. It allows less room for wear and requires more pressure to release the liner lock bar from the tang when closing the knife.

 

[alan0354]

The slope of the tang landing pad allows for wear. It is a self-adjusting mechanism. Hence, why late lockup (the leftward sample in your pic) is inferior. It allows less room for wear and requires more pressure to release the liner lock bar from the tang when closing the knife.

Thanks, do you mean (D) on the right side?

 

[toker]

I'm also of the opinion that it doesn't matter where the liner lock ends up, as long as there is no lock rock.

I would focus more on the other part of the lock relationship.
https://emersonknives.com/uncategorized/emerson-knife-anatomy/

 

[alan0354]

I'm also of the opinion that it doesn't matter where the liner lock ends up, as long as there is no lock rock.

I would focus more on the other part of the lock relationship.
https://emersonknives.com/uncategorized/emerson-knife-anatomy/

Thanks, that's what I figure.

I actually use Sharpie to paint the surface of the line lock face that are in contact to the bottom of the blade. Put it back together, flip the knife for a while, open it and look at the ink wear mark to make sure the wear is on #3 in the picture on the left.

From the theory of lever action, use the point as far from pivot point(2) as possible.

Thanks

 

[marthinus]

Hi, thanks for the suggestion, I checked, it's very expensive and I think this is quite simple to design. I gave it some thought and this is what I come up and I want to get your opinion:



To ensure longevity, I decided to only file the liner so it barely goes deeper than the left surface of the bottom of the blade as show in the picture on the left. So it still have a long way to wear to get to the right side.

The most important thing I did is to bend the liner lock out so it put more pressure towards the right side so it make it harder to being push to the left. To me, from talking here, that's the MOST IMPORTANT thing or safety and reliability. Of cause this will make it hard to open.

To solve the problem of hard to open because of the extra pressure towards the right, I use a diamond bit to flare out the hole on the blade where the protrusion on the liner fit into the hole on the blade. That really make it easy to open, NO DIFFERENT from the original knife.

My question is what is your opinion on the angle to grind on the liner lock shown in (B), (C) and (D) in the drawing. I pick (C) so it's not to steep angle like (D) where it wear out faster.

Let me know your opinion and what advice you have.

Thanks

Alan

PS: The knife is Steel Will with bronze washers, no ball bearing. So there is very little gap between the metal liners and the blade. So even if the liner lock wear so it goes all the way to the right, it will be stopped by the metal liner on the right to prevent it from moving pass the bottom of the blade. I actually screwed up one and grind the liner short enough and travel all the way to the right and I actually feel it is quite secure, no free play on the blade, it won't wear out any further as it is rested against the right liner.

I really don't care about the ease of closing the knife, the most important to me is ONE HAND FAST DEPLOY for self defense. I can take my time to close the knife.

to me, the knife is for self defense, it has to have long flipper tap so after it deployed, it will serve as safeguard to prevent the knife from being shoved back to my hand when I thrust and hit hard object. To me that is the UTMOST IMPORTANT FEATURE. There is no other way to protect the hand. A lot of nice looking knives are very stream line and pretty, they don't put the tap and it's useless to me.

Unfortunately a liner lock and framelock is not as simple as it might appear. Hence my long replies on the matter.

The book is expensive but worth it if you are interested in doing this on a longer term basis.

What you are currently doing is adjusting the lock to fit the blade, this is not ideal.

You want to clean up the spring/liner, then fit the lock face of the blade to the spring/liner.

 

[alan0354]

Unfortunately a liner lock and framelock is not as simple as it might appear. Hence my long replies on the matter.

The book is expensive but worth it if you are interested in doing this on a longer term basis.

What you are currently doing is adjusting the lock to fit the blade, this is not ideal.

You want to clean up the spring/liner, then fit the lock face of the blade to the spring/liner.

Sorry I don't see it's that complicate, it is simple geometry, friction. Yes, if you start talking about Ti vs Steel and all that, it gets complicated. But here I am talking about very specific Steel Will that is steel to steel contact. Given this parameters, it should be very simple, just angle.

To me, I never understand why people don't bend more on the liner towards the right to put more pressure to the right, IT WILL MAKE EVERYTHING MORE SECURE. Then just compensate by flaring out the Detent hole to make it easier for the Detent ball to slip out of the hole. I can assure you it work beautifully. It will put more pressure towards the right, it will prevent any slippage given other parameters remain the same. this is so simple.

Also, I stay away from those with ball bearings. people has to either thin out the blade around the pivot hole, or make the liner thin at the pivot to fit the thick bearings. OR put a lot of space between the blade and the liner that make the knife less stable. All these create a weak point on the folder knife.

No offense, this is not rocket science. I just want to hear from people what I miss. Actually from talking, I think I got a lot of it covered. At the beginning in post #3, I made the mistake of drawing the bottom of the blade with too much curve that make the angle of contact steeper if I grind the liner to move more to the right and make it less stable. BUT I actually looked at the bottom with magnifying glass, they are quite straight, not curve. Meaning it doesn't matter if I make the line go to the middle under the blade. It will make no difference in reliability.



If you think I am missing the moon, let me know what I missed.

Thanks

 

[marthinus]

Sorry I don't see it's that complicate, it is simple geometry, friction. Yes, if you start talking about Ti vs Steel and all that, it gets complicated. But here I am talking about very specific Steel Will that is steel to steel contact. Given this parameters, it should be very simple, just angle.

To me, I never understand why people don't bend more on the liner towards the right to put more pressure to the right, IT WILL MAKE EVERYTHING MORE SECURE. Then just compensate by flaring out the Detent hole to make it easier for the Detent ball to slip out of the hole. I can assure you it work beautifully. It will put more pressure towards the right, it will prevent any slippage given other parameters remain the same. this is so simple.

Also, I stay away from those with ball bearings. people has to either thin out the blade around the pivot hole, or make the liner thin at the pivot to fit the thick bearings. OR put a lot of space between the blade and the liner that make the knife less stable. All these create a weak point on the folder knife.

No offense, this is not rocket science. I just want to hear from people what I miss. Actually from talking, I think I got a lot of it covered. At the beginning in post #3, I made the mistake of drawing the bottom of the blade with too much curve that make the angle of contact steeper if I grind the liner to move more to the right and make it less stable. BUT I actually looked at the bottom with magnifying glass, they are quite straight, not curve. Meaning it doesn't matter if I make the line go to the middle under the blade. It will make no difference in reliability.



If you think I am missing the moon, let me know what I missed.

Thanks

If all you want is the most stable lock, grind a pocket in the blade for the liner lock to fit into.

You will introduce blade play, but the lock wont fail in terms of slipping. This was covered in one of my earlier posts.

You are right. It is all about the geometry as I mentioned in post 37.

 

[J. Doyle]

To me, I never understand why people don't bend more on the liner towards the right to put more pressure to the right, IT WILL MAKE EVERYTHING MORE SECURE. Then just compensate by flaring out the Detent hole to make it easier for the Detent ball to slip out of the hole. I can assure you it work beautifully. It will put more pressure towards the right, it will prevent any slippage given other parameters remain the same. this is so simple.

You appear to be trying to force people to bend to your will under the guise of "open minded discussion".

You keep admitting you know nothing about making knives but then continue to talk down and dismiss the proven ideas of people who DO know what they're doing.

This is a matter of perspective, period. YOU are attempting to impart ultimate strength (for God only knows what purpose) to a folding knife.....at the expense of LITERALLY EVERYTHING else. And vastly over-thinking and over-complicating a relatively simple concept.

Meanwhile, almost EVERYBODY ELSE wants a perfect balance of strong, secure lockup with no lock rock, early lockup for longevity, nice smooth action, perfect blade centering and ease of closing. You are, either unintentionally or purposely, dismissing the craftsmanship of the maker(s).

A properly made liner lock can exhibit all the traits I just mentioned PLUS have extremely early lock up and still stand up to anything you should ever use a folding knife for and THEN SOME.......including the dreaded (and stupid) HARD spine whacks.

Of course feel free to continue this futile effort to convince everyone that you alone hold the key to building a better mousetrap. As I've told you before.....I look forward to seeing your vastly improved liner lock folders when they finally hit the market and the huge following they'll have........you know.....since you've said before how simple and easy it is

 

[Guy McVer]

In my opinion the optimal position of a liner lock is all the way against the opposite edge of the blade so that it is stopped by the handle and has to travel the full width of the blade backwards to disengage. That's from a safety standpoint. That's also assuming that there's no significant flex in the handle which would allow the liner lock to keep moving past the edge of the blade.

Of course all locking mechanisms should be treated as if they can fail at any time without warning. They should be regarded as unreliable and not worthy of trust. If you value your fingers. I know that I like my fingers a lot. Me and my fingers are best buddies and I never want to be separated from any of them.

 

[Greggy]

Thanks, do you mean (D) on the right side?

No, the leftward knife in your initial post and pic.

 

[Greggy]

This reminds me of when I first received my Kizer Horn liner lock knife. Had, what seemed to me, early lockup and failed a moderate spine whack. I was not happy. I took apart the knife and began to examine the "geometry" of a liner lock. I came to realize and appreciate the intricacy of the design. As a result, I put away my files and sandpaper. Over time the knife has improved and I no longer have issues, it has worn in just right.

 

[alan0354]

No, the leftward knife in your initial post and pic.

OK, got it. I was referring to another post which is on the right.

thanks

 

[alan0354]

You appear to be trying to force people to bend to your will under the guise of "open minded discussion".

You keep admitting you know nothing about making knives but then continue to talk down and dismiss the proven ideas of people who DO know what they're doing.

This is a matter of perspective, period. YOU are attempting to impart ultimate strength (for God only knows what purpose) to a folding knife.....at the expense of LITERALLY EVERYTHING else. And vastly over-thinking and over-complicating a relatively simple concept.

Meanwhile, almost EVERYBODY ELSE wants a perfect balance of strong, secure lockup with no lock rock, early lockup for longevity, nice smooth action, perfect blade centering and ease of closing. You are, either unintentionally or purposely, dismissing the craftsmanship of the maker(s).

A properly made liner lock can exhibit all the traits I just mentioned PLUS have extremely early lock up and still stand up to anything you should ever use a folding knife for and THEN SOME.......including the dreaded (and stupid) HARD spine whacks.

Of course feel free to continue this futile effort to convince everyone that you alone hold the key to building a better mousetrap. As I've told you before.....I look forward to seeing your vastly improved liner lock folders when they finally hit the market and the huge following they'll have........you know.....since you've said before how simple and easy it is

I said I don't know the details about folding knives, BUT I did say I am very familiar with mechanical engineering. I ask experience people to explain, I have my opinion, I want people to criticize my conclusion. BUT at the same time, I do want to challenge if I don't agree with it.

I am not trying to convince anyone, just discussion and I voice my opinion when I disagree.

I don't claim I am right, in fact I was wrong in post #3 that the bottom of the blade is curved. In fact I ended up putting the liner only slightly pass the left surface of the blade so there are more room for wearing instead of putting the liner all the way to the right as explained by Blue Sky on the force on x direction increase in post #23.

What I don't buy is just because everyone doing that, it got to be right and I should follow. This is engineering, everything is up for debate and apply theory. from what I see on a lot of knives, I am not sure everyone knows engineering. To put it politely.

Yes, I have particular things I emphasize, and things I disregard. To me, a knife is NOT a fashion, you don't carry to show off. A knife is a utility tool or for self defense. RELIABILITY IS OF UTMOST IMPORTANCE. For self defense, fast one hand deploy is of utmost importance. Ease of closing is not important.

Yes, I can never get a knife is for status, fashion, for showing off. I am actually surprised that people treat knives like women treating their handbags, name brand, designer name, nice looking and all that. That's just me.

In fact, no offense to designers, how one justify a folding knife that cost $300? It is pure name? Or are they actually superior mechanically?

 

[J. Doyle]

What I don't buy is just because everyone doing that, it got to be right and I should follow. This is engineering, everything is up for debate and apply theory. from what I see on a lot of knives, I am not sure everyone knows engineering. To put it politely.

I'm not sure you know knifemaking, to put it politely.

Yes, I have particular things I emphasize, and things I disregard. To me, a knife is NOT a fashion, you don't carry to show off. A knife is a utility tool or for self defense. RELIABILITY IS OF UTMOST IMPORTANCE. For self defense, fast one hand deploy is of utmost importance. Ease of closing is not important.

You ask for input from those with actual experience but don't listen anyway when it actually happens.

In fact, no offense to designers, how one justify a folding knife that cost $300? It is pure name? Or are they actually superior mechanically?

Make one by hand start to finish then let us know what it's worth.

 

[alan0354]

I'm not sure you know knifemaking, to put it politely.


You ask for input from those with actual experience but don't listen anyway when it actually happens.


Make one by hand start to finish then let us know what it's worth.

I don't know knife making, but I sure as hell know engineering.

I don't listen to all because I see TOO MANY STUPID DESIGN that just looking at it tells me they have no common sense.

You don't have to make one to know, there are common sense and if I sell product, I'll set up production to cut cost. tell me what $300 knives are better than the design of Steel Will knives that are in range of $40 to $70 dollars other than the name. I own quite a few Steel Will and I think they have the best design in practical sense for ruggedness, practical, self defense.

 

[J. Doyle]

I don't know knife making, but I sure as hell know engineering.

I don't listen to all because I see TOO MANY STUPID DESIGN that just looking at it tells me they have no common sense.

You don't have to make one to know, there are common sense and if I sell product, I'll set up production to cut cost. tell me what $300 knives are better than the design of Steel Will knives that are in range of $40 to $70 dollars other than the name. I own quite a few Steel Will and I think they have the best design in practical sense for ruggedness, practical, self defense.

Well you've got it all figured out it sounds like.

I'll bow out now because until you actually produce something of your own, you're all talk.

 

[MolokaiRider]

Pic attached for fun.

I think if a liner is allowed to travel all the way over to the opposite scale, you introduce more potential weakness in the liner lock.

Since the topic is about strength, I would guess that having the liner less in parallel can cause this.

 

[alan0354]

Well you've got it all figured out it sounds like.

I'll bow out now because until you actually produce something of your own, you're all talk.

these to me are bad design.


This isKubey KU901. look at the thickness of the pivot hole that is thinned out for the ball bearings. I think it's as thin as 0.03". This can be fixed so easy by thinning out a little on the liner and keep the thickness to about 0.06".

This is Off Grid Enforcer. It's the opposite of the Kubey. they left the pivot hole of the blade untouch, BUT they thin out both liners around the pivot hole, it must be like 0.02" thick. I return this one. It's not cheap but the design. HOW STUPID IS THAT.

You tell me these people know their stuffs?

 

[Guy McVer]

I think if a liner is allowed to travel all the way over to the opposite scale, you introduce more potential weakness in the liner lock.

Since the topic is about strength, I would guess that having the liner less in parallel can cause this.

I'm sure that there are more factors involved than the travel distance of the end of the liner lock. There's the overall shape, the thickness, the composition of the metal, and potentially a heat treat also comes into play. That's off the top of my head.