I thought long and hard and decided to repost this thread that I deleted a few days ago. I really want to know the answer and it's bugging the heck out of me.
Please, let's not bash on each other or the knife. Please try to stick to the question at hand as I will delete this thread if it gets out of hand.
So, what I'm wondering is this: Why does the ball bearing on the CBL (caged ball lock) just barely engage on the blade tang? I know with a lot of things in engineering you don't need much contact or overlap for something to work. Is that the case here? I currently have 3 samples of the Manix 2 and all of them barely lock up. I have one from late 2010 and the others are from 2012 and they all lock up exactly the same. You can see the line on the blade tang where the ball bearing rides and where it stops when it's locked up. It stops only about 1mm onto the tang. It might be 1.5mm but I doubt it. If you don't know what a millimeter is look it up. It's not much. It's 1/10th of a centimeter. There is a LOT of space on the tang for that ball to ride on and I don't see why the ball isn't 2-3 mm further onto the tang. Now, while I don't plan to abuse it or spine whack it, it does look like, where the ball sits right now, if I whacked the spine that it could coin the tang of the blade and possibly unlock. If the ball was moved say 2mm further onto the tang it might simply leave a dimple in the blade tang when whacked. Right now, if the tang were to be coined so close to where it starts to round off it seems that the lock would defeat. I know it gives the lock room to wear but it's a ball bearing and I doubt that there will be much wear at all EVER on this knife.
I will take a picture later to show what I'm talking about for those that don't know.
Admittedly this probably doesn't matter as long as the knife locks up and you use it like a knife should be used. I am a fan of overbuilt stuff. To me, the more overbuilt the better (to the point of diminishing returns). I guess I just don't understand why they choose to just have the ball just barely sitting on the flat part of the tang. Seems odd to me, but I don't know everything in the world. :)
Edited to add this pic:
What say ye?
"I'm calling YOU ugly, I could push your face in some dough and make gorilla cookies." -Fred Sanford
David Lowry wrote:I know with a lot of things in engineering you don't need much contact or overlap for something to work.
I'm no engineer either, David, but I think you answered your own question. And, as far as wear goes, while ball bearings may wear slowly, if at all, their races tend to wear more so, perhaps, that's part of the reason. Beyond that, I don't consider it blind faith to have a high degree of confidence in Spyderco's engineering. Especially when, after several years on the market, the only case I'm aware of where a Manix 2 failed due to anything other than a broken spring was the result of a combination of intention abuse and neglect.
That said, given the breadth and depth of Spyderco's lineup, there's no good reason to use a tool you have less than 100% confidence in, regardless of how others feel about it.
kbuzbee wrote:I wondered what you'd deleted (mm? Really? I think we all know what a mm is 1 millimeter = 1.05702341 × 10-19 light years )
IMO, it's to facilitate ease of disengaging the lock. Set it deeper and it sticks too much, but that's only a guess.
As to your scenario, I know folks use their knives differently but that would constitute abuse if it were MY knife
Hope you get a better answer.
Ken
Hey Ken,
I agree. I think that is abuse as well and I don't ever abuse my knives. I really am just wondering about the engineering behind it and the reason why? It just seems that it wouldn't hurt anything to make it engage further but I don't know.
The Deacon wrote:I'm no engineer either, David, but I think you answered your own question. And, as far as wear goes, while ball bearings may wear slowly, if at all, their races tend to wear more so, perhaps, that's part of the reason. Beyond that, I don't consider it blind faith to have a high degree of confidence in Spyderco's engineering. Especially when, after several years on the market, the only case I'm aware of where a Manix 2 failed due to anything other than a broken spring was the result of a combination of intention abuse and neglect.
That said, given the breadth and depth of Spyderco's lineup, there's no good reason to use a tool you have less than 100% confidence in, regardless of how others feel about it.
Paul, I agree with you as well. I only know about 1 or 2 problem Manix 2's and 1 of those was what I consider abuse. I would say that I almost have blind faith in Spyderco. I however am always asking "why" and I have learned a ton like that. The folks at Spyderco know their stuff and sometimes I like to pick their brain a bit. :)
"I'm calling YOU ugly, I could push your face in some dough and make gorilla cookies." -Fred Sanford
my guess, and this is a total shot in the dark, is that even if the bearing wears slowly, the smallest amount of wear will cause it to engage further given the nature of the lock...so they start with an earlier lockup to give it some time to really seat well.
I took a look at my old M2 and it seats nearly all the way in...it has been used a lot...plus I used to flick it a lot on top of that.
I agree. I think that is abuse as well and I don't ever abuse my knives. I really am just wondering about the engineering behind it and the reason why? It just seems that it wouldn't hurt anything to make it engage further but I don't know.
Paul, I agree with you as well. I only know about 1 or 2 problem Manix 2's and 1 of those was what I consider abuse. I would say that I almost have blind faith in Spyderco. I however am always asking "why" and I have learned a ton like that. The folks at Spyderco know their stuff and sometimes I like to pick their brain a bit. :)
The first time I took my Manix2 apart I thought the exact same thing. I thought the bearing may shoot out of the locked position like a miscued cueball allowing the blade to close. However as long as the CENTER of the bearing is on a flat spot on the tang it will NOT MISCUE and the blade will not close. I believe it was Ankerson a year ago or more who had the Manix2 lock fail during overstrike tests. Spyderco investigated and whatever happened happened. I think all is well and thought I never hit the spine of my Manix2s on anything (why would anyone do that unless they were testing a knife?) but I confidently stabbed wood many times just for fun and to see how solid the knife felt. IMO you have nothing to worry about. I hope you have played enought pool to understand my "miscue" comment. If not, let me know. :) I am the miscue champ. :D
The bearing has lots of room for wearing the tang and I don't think much wear will occurr in real life situations. It releases the lock as easily as possible. I thing these are the reasons it stops where it does when brand new as stated before.
My opinions only. They are not backed by anyone with any sense. :)
I agree. I think that is abuse as well and I don't ever abuse my knives. I really am just wondering about the engineering behind it and the reason why? It just seems that it wouldn't hurt anything to make it engage further but I don't know.
Paul, I agree with you as well. I only know about 1 or 2 problem Manix 2's and 1 of those was what I consider abuse. I would say that I almost have blind faith in Spyderco. I however am always asking "why" and I have learned a ton like that. The folks at Spyderco know their stuff and sometimes I like to pick their brain a bit. :)
The first time I took my Manix2 apart I thought the exact same thing. I thought the bearing may shoot out of the locked position like a miscued cueball allowing the blade to close. However as long as the CENTER of the bearing is on a flat spot on the tang it will NOT MISCUE and the blade will not close. I believe it was Ankerson a year ago or more who had the Manix2 lock fail during overstrike tests. Spyderco investigated and whatever happened happened. I think all is well and though I never hit the spine of my Manix2s on anything (why would anyone do that unless they were testing a knife?) I confidently stabbed wood many times just for fun and to see how solid the knife felt. IMO you have nothing to worry about. I hope you have played enough pool to understand my "miscue" comment. If not, let me know. :) I am the miscue champ. :D
The bearing has lots of room for wearing the tang and I don't think much wear will occurr in real life situations. It releases the lock as easily as possible. I thing these are the reasons it stops where it does when brand new as stated before.
My opinions only. They are not backed by anyone with any sense. :)
Just pulled out one of mine and I see what you mean, but I am confident that the design is meant to allow for a LOT of use, and mine have not moved noticably or ever unlocked accidentally in many thousands of openings and lots of use.
It's very interesting to think about the engineering that goes into something that most folks would call "simple". If you think about it, the ball lock has to be perfect in some ways. Since it is a ball bearing, if the ramp (or flat area) that it rolls on to when the knife is locked, is not absolutely true (level from side to side) the ball may deflect to one side or another. This wouldn't mean much in most normal use. However, if put under a lot of pressure, the ball would want to "slide downward" to whatever side of the surface is lower, which would most likely break the cage that the ball is in on one side or another.
Not complaining here, it's just amazing the kind of thought and engineering that goes into something like this. Totally kick butt!
"I'm calling YOU ugly, I could push your face in some dough and make gorilla cookies." -Fred Sanford
David Lowry wrote:It's very interesting to think about the engineering that goes into something that most folks would call "simple". If you think about it, the ball lock has to be perfect in some ways. Since it is a ball bearing, if the ramp (or flat area) that it rolls on to when the knife is locked, is not absolutely true (level from side to side) the ball may deflect to one side or another. This wouldn't mean much in most normal use. However, if put under a lot of pressure, the ball would want to "slide downward" to whatever side of the surface is lower, which would most likely break the cage that the ball is in on one side or another.
Not complaining here, it's just amazing the kind of thought and engineering that goes into something like this. Totally kick butt!
The amazing part is in how simple it is. Always follow the K.I.S.S. method and you can't go wrong. Another reason for the lockup difference is obviously factory tolerances. I'm sure somewhere there's a Manix 2 that locks WAY down the tang, and then there's probably some that don't lock far enough and need sent back in. I'd say the margin of error for any lock design is quite thin. If you go too far one way or another, you end up with not enough lockup and an unsafe knife, or too much lockup and blade play. I'll take a knife that locks up too early over one that locks way late.
If a lock passes the strength test excessive lock-up only adds tension to disengaging as Ken says.
Things can be visually disconcerting but that doesn't always mean there is a tangible difference/danger. If that perception changes the way you use a product I guess there is a difference worth measuring.
Some would rather have heavy knives because they "feel tougher". These people are still gaining a tangible benefit even if merely psychological.
David Lowry wrote: Since it is a ball bearing, if the ramp (or flat area) that it rolls on to when the knife is locked, is not absolutely true (level from side to side) the ball may deflect to one side or another.
This is the only thing that concerns me regarding the caged ball lock. Seems to me that the only thing keeping the ball from escaping through the hole on the side of the scales/liners, is the cage. My Manix 2 has no blade play whatsoever but the cage has a bit of side to side play, I wonder if this may eventually lead to problems down the road?
Among other reasons to have some confidence in the design and manufacturing, consider the discipline of the market also...if there were even a few failures, given the attitudes prevalent in American society today, injured consumers would have shut Spyderco (or whatever other knife maker we'd be talking about) down with lawsuits.
a2d2 wrote:This is the only thing that concerns me regarding the caged ball lock. Seems to me that the only thing keeping the ball from escaping through the hole on the side of the scales/liners, is the cage. My Manix 2 has no blade play whatsoever but the cage has a bit of side to side play, I wonder if this may eventually lead to problems down the road?
Yes but the cage itself is only controlling lateral pressure. The lion share of the force is being pushed upwards rather than out.
As JNewell said the amount of Spyderco knives on the market and the lack of cut fingers due to lock failures is amazing. It says a ton for the quality of product being put out there given the variety of user care. Even dirty lockbacks don't snap often.
Blerv wrote:Yes but the cage itself is only controlling lateral pressure. The lion share of the force is being pushed upwards rather than out.
As JNewell said the amount of Spyderco knives on the market and the lack of cut fingers due to lock failures is amazing. It says a ton for the quality of product being put out there given the variety of user care. Even dirty lockbacks don't snap often.
I agree, though it will likely always be in the back of my mind.
a2d2 wrote:This is the only thing that concerns me regarding the caged ball lock. Seems to me that the only thing keeping the ball from escaping through the hole on the side of the scales/liners, is the cage. My Manix 2 has no blade play whatsoever but the cage has a bit of side to side play, I wonder if this may eventually lead to problems down the road?
I think something like this would be covered under warranty if no obvious abuse was found.
JNewell wrote:Among other reasons to have some confidence in the design and manufacturing, consider the discipline of the market also...if there were even a few failures, given the attitudes prevalent in American society today, injured consumers would have shut Spyderco (or whatever other knife maker we'd be talking about) down with lawsuits.
This the internet. The day one of these locks completely fails like that, we'll all hear about it because it'll be on You Tube minutes after it happened. Look at Ankerson's test..love it or hate it, it caught everyone's attention.
I made a thread about how far the ball engaged a couple years ago when i had my M2. I had asked for pics of how far other knives were engaging, because i felt that maybe that was the issue with the knife that Ankerson tested. We didn't really get anywhere with that thread, but i think as far as the pic in the first post goes, that's plenty of engagement. As long as the ball is on the plane of the tang at or past bottom dead center of the curve of the ball, it's not going to slip off unless it's "bounced" off, as with the case with a spine whacking test. If the ball wasn't engaging at least that far then you'd be able to force the blade shut just by pressing on the spine, so if you can't then you should be perfectly fine and it'll only get better with use.
(mm? Really? I think we all know what a mm is 
