BIG Lock Engagement Difference between Slow-Roll and Flicking Open. What's the cause?

[Initialconditions]

***I am not planning on specifying what company or knife this is as of yet. Depending on what I hear from the company, I may update my position***

Somehow slow-rolling this knife causes MUCH deeper lock engagement vs flicking it open.

Hoping for EXPERIENCED knife makers, or craftsman, etc to weigh in on what on earth might be causing this.

There is no lock stick, rock, or play.

In my experience flicking open a knife can cause slightly more engagement vs slow-rolling it open (the Umnumzaan comes to mind). But I have NEVER seen a knife's lock seat deeper the slower you open it.

To be clear, I am not pushing on the lockbar during the slow roll anymore than I am pushing on it when I flick it open. (it seats deeper even if I open it slowly without touching the lockbar at all).

 

[Tsujigiri]

It could be bouncing off the stop pin when you open it quickly and locking up there. Shouldn't be anything to worry about if it's locking up securely either way, right?

 

[Delgadonine]

Slow=Safe

Actually: Give us the example of use that raised your concerns. Please.

 

[Bob Denman]

It could be bouncing off the stop pin when you open it quickly and locking up there. Shouldn't be anything to worry about if it's locking up securely either way, right?

Yup! Nothing to worry about.

 

[Sharp & Fiery]

Try flicking it open and then cutting something. Downward preferably with some force. Then check the lockup.

It’s probably bouncing during the flick and the lock only makes it to 50%

 

[Sam Wilson]

So, to be clear, is there an actual problem or is this an OCD thing or you interested in the physics of it all?

Sam

 

[Blues]

So, to be clear, is there an actual problem or is this an OCD thing or you interested in the physics of it all?

Sam

I'm sorry, Sam, you've exceeded your allotted number of questions for the day.

 

[Sam Wilson]

I'm sorry, Sam, you've exceeded your allotted number of questions for the day.

 

[Initialconditions]

The simple answer to all the "is there a problem" and "are you OCD" goofiness should be somewhat obvious by my initial question... But I'll humor you all with an answer anyway. I don't know if this is a problem, that's why I'm asking. Same way you take a car that is making a new noise to a mechanic, or go to the doctor when something doesn't feel right.

I have owned, and used a LOT of knives and never seen this before, so my suspicion was that this is some type of problem and would potentially cause issues later. Even if that issue is as simple as wearing away the lock face prematurely.

I'll try the suggested check to see if it's bouncing against the stop pin. My novice guess was that the lock geometry was a bit wonky and slow rolling it resulted in the initial blade/lockbar contact being in a place that's prone to deeper engagement vs flicking it open where perhaps the blade hits the lockbar in a slightly different spot resulting in less engagement.

Lastly, if slow = safe, I'm also in the camp that consistent lockup = safe and variable lockup = red flag.

 

[Sam Wilson]

In all fairness, I never called you goofy. There are tons of questions like this in the forums and frequently it roots from people just staring at the knife and opening and closing it and flicking it and playing with it.

Many, many times long threads are engaged in like this and finally we find out that there was never an actual problem. The person just was using it as a fidget toy, basically. So respectfully, that is the root of the question.

If you stated that it was some sort of actual performance problem in your post, I missed it. If it is just varying degrees of lockup, this is extremely common in many knives that I have had over the years. Certainly not all, but I have noticed different levels of engagement due to different methods of deployment more times than I can count, on customs and factory knives.

So to answer that particular question, at this point it is not something I would concern myself with.

Sam

 

[Bob Denman]

You should be hearing a difference between the slow-roll, and the fidgety lockups. There'll be an extra metallic "click"; as the stop pin is hit...

 

[Delgadonine]

The simple answer to all the "is there a problem" and "are you OCD" goofiness should be somewhat obvious by my initial question...

Lastly, if slow = safe, I'm also in the camp that consistent lockup = safe and variable lockup = red flag

I didn't mean to question your experience or knowledge.

I was hoping to learn more about context.

Use of the knife?

 

[Initialconditions]

As a further point of clarification, a knife is a tool I plan to use, so upon receipt, I inspect it. One of the things I check, and would suggest everyone check is lock engagement with different deployment methods or speed. The origin of this is I have had a couple knives that failed to lockup while slow-rolling (hence, not safe at all). Those knives, it seemed required the lowered friction, and perhaps extra clearance, afforded while being flicked open. Suffice it to say I will not own a knife in which the lock might fail simply because I took my time opening it.

In this instance, I would also not want to own a knife that would be prone to problems cropping up because the lockbar geometry was off slightly to begin with (as was my suspicion). But, it is somewhat helpful to know some of you feel it's a non-issue. I will reserve judgement until others chime in, or frankly if I continue to use the knife and see how it ages.

 

[Delgadonine]

Thank you

 

[Sam Wilson]

 

[Initialconditions]

Le mio

 

[BlindMouse2of3]

I would honestly say if it's brand new run it and see how it wears in. Cut some stuff open and close it a few hundred times. Then revisit the lockup. Being a frame lock your bound to push in on it under heavy use anyways. Once the mating surfaces have lapped themselves things should settle in nicely. Just my .02 but think of it like new valves in a car.

 

[Initialconditions]

I would honestly say if it's brand new run it and see how it wears in. Cut some stuff open and close it a few hundred times. Then revisit the lockup. Being a frame lock your bound to push in on it under heavy use anyways. Once the mating surfaces have lapped themselves things should settle in nicely. Just my .02 but think of it like new valves in a car.

Much appreciate the measured, thoughtful response. Also, appreciate the information about how the lockbar and blade lap themselves; cool to know. Thanks, I'll take your advice

 

[DavidABQ]

Try flicking it open and then cutting something. Downward preferably with some force. Then check the lockup.

It’s probably bouncing during the flick and the lock only makes it to 50%

Yeah, I am going with this.

 

[hhmoore]

I have one of his knives from 2002 I was looking for some history and value of it

I have had a couple knives that failed to lockup while slow-rolling

I had that on a custom, which was quickly remedied by the maker.
Worse, IMO, are the ones that barely engage the lock but disengage with minimal downward pressure. It's easy to assume that the blade is locked if you don't have reason to check.

To your original question, I've never noticed one with deeper engagement on a slow opening than with a flick (assuming it is a solid flick...if it's a barely getting there flick, I could see that happening)