Skeletonized Liners - one mans 2 cents

[The Deacon]

Rant on:

That's something I'll never truly understand. People whine and complain about what they want Spyderco to start doing to their knives, to make them better (adding steel liners, using PB washers, using XXX steel) and then they whine and complain about it when Spyderco listens to them and actually does it.

Rant off:

Regards,
3G

Possibly because you're making the assumption that all "knife lovers" see a knife the same way and want the same things. Truth is, one person's idea of improvement is another person's idea of tampering with perfection, or moving further away from it rather than toward it. One person's candidate for the "next latest and greatest super steel" is another person's idea of just another monotonous, monocromatic, grey metal. What one views as improving the "tactical" ability of a knife, another views as one more potential nail in the coffin of their right to carry a knife.

Truth is, nothing is universally loved. Probably a good thing, discontent is what drives change. But not everyone will agree on whether a given change is a change for the better.

Me, I'm happy with the skeletonized liners on my Stretch II. It's plenty rigid, and gets washed often enough to make crud a non-issue for me. But, if given the choice, would add front bolsters and fill in the Boye dent, two changes that would more than balance out the weight savings of the liners. But the weight of those things would be balanced out, for me, by the improved looks of the knife, while full liners would add nothing of value to me.

Paul

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[huugh]

Skeletonized liners or not, no big deal. I understand using full liners as a support base for some materials (especially brittle). But what I do not understand, IF the modern day materials (and I mean here CF, G-10 and FRN) are already used for scales, why there aren't more knives built like Military? What is the point of G-10 or even CF if only purpose they serve is being slapped to the sides of steel liners?

 

[Th232]

I'd go with weight and texture. Some people prefer the heft, and it's probably easier and cheaper to get pre-textured G10/CF than it is to find SS with the same.

Oh, almost forgot, for CF, looks.

 

[Bushman5]

Any time I go on a ROTC paintball trip i will usually address the feild owners and staff members as sir and its pretty funny how i almost always hear that comment.

I wonder if you called a homeless man sir would he be like bingo you got me im unemployed..

the first time i heard that (dont cal me Sir.....) it was from a CDN Army Veteran from WW2. He spat on the street and cussed about how the '******* Officers did nothing but sit on their butts and eat real food /coffee while the real men went and fought the war for them, living on bacon grease and crusty bread and strong tea". It was pretty funny....

 

[Roger999]

X2 with the liners, it's like 3g off the weight, which is unnoticable.

 

[3Guardsmen]

hey i'm not a Sir, i work for a living!

no worries my fellow blade nut! :thumbup:

Roger that, my friend!:thumbup:

Regards,
3G

 

[3Guardsmen]

Possibly because you're making the assumption that all "knife lovers" see a knife the same way and want the same things.

You're right, Deacon, I was a bit broad with the brush. I should have stated that the general concensus on the forums was that nested liners should be added to the Delica/Endura line. Obviously not everyone was on board with the idea, or even on 'the boards' when the input for upgrades was being solicited.

Regards,
3G

 

[Bushman5]

^ yeah i dont think i was around then..........

 

[Carpdiem]

I feel like I should point this out, but skeletonized liners can actually be *stronger* than full liners.

Think about it like the difference between a pipe and a rod. If you hang two weights off the ends of a solid rod, and support it in the middle, it'll bend. If you do the same with a pipe, it'll bend much less. This is because the hollow pipe essentially has to 'kink' in order to deform, whereas the solid rod just deforms.

So your skeletonized liners actually save you some weight and likely leave you with a stronger knife. This is, of course, assuming that the holes are put in the right places and sizes, which I'm confident in given Sal's record.

 

[THG]

Think about it like the difference between a pipe and a rod. If you hang two weights off the ends of a solid rod, and support it in the middle, it'll bend. If you do the same with a pipe, it'll bend much less. This is because the hollow pipe essentially has to 'kink' in order to deform, whereas the solid rod just deforms.

But a pipe and a rod are 3D. With a liner, you're dealing with mainly 2 dimensions.

 

[Th232]

Concur with THG. The different dimensions and orientations of the holes make them two separate cases. The direction that the most common flexing force will be acting in (for example, pushing on the middle of the handle) will be in such a direction that skeletonising the liners will make it weaker. If it was in another direction, then that might possibly be true.

 

[Cotherion]

I feel like I should point this out, but skeletonized liners can actually be *stronger* than full liners.

Think about it like the difference between a pipe and a rod. If you hang two weights off the ends of a solid rod, and support it in the middle, it'll bend. If you do the same with a pipe, it'll bend much less. This is because the hollow pipe essentially has to 'kink' in order to deform, whereas the solid rod just deforms.

So your skeletonized liners actually save you some weight and likely leave you with a stronger knife. This is, of course, assuming that the holes are put in the right places and sizes, which I'm confident in given Sal's record.

My company does testings on the bending ability of materials (for one of our functions) and for pipes it is the thicker the wall of the pipe = better/increased bending capacity. Meaning the less of a material = reducing strenght. Our tests conclude that a solid rod has the most bending capacity. (even with taking into account the effect of the increased weight)

Oftentimes the purpose of reducing material is to save weight (or cost if circumstances permit but not likely in most times). The general rule of thumb is to reduce the material at places which are 'neutral' places which experience the least forces or least critical. There will always be a reduction in strenght but the skill is to minimise the danger by balancing the material loss with required strenght.

It is even more so the case with skeleton liners. Flexing a piece of uncut SS plate and compared with one with holes in it will show that the lesser material one (the holey one ) will flex more for the same given loading. It is simply a case of the reduced cross sectional area hence reduced moment capacity. On the 'gripping till me knuckles turn white' plane of loading (meaning the force which will result in the skeleton liners collapsing inwards) there is a reduced amount of material hence reduced strenght.

PS : one (corrected by THG) exception to the case are for materials where the bending strenght is relatively low and their density is high like concrete. Then by reducing material will result in net gain in moment capacity but it is more obvious in beams and not really in columns...

PSPS : Pointed out by THG, the above holds true assuming the external shape/size being compared is the same.

 

[THG]

PS : only exception to the case are for materials where the bending strenght is relatively low and their density is high like concrete. Then by reducing material will result in net gain in moment capacity but it is more obvious in beams and not really in columns...

http://www.engr.sjsu.edu/bjfurman/courses/E10/E10pdf/Structures_Stiffness.pdf

Check out pages 12, 13, 14. I'm not arguing for either side; I just Googled and found this appropriate.

 

[Cotherion]

http://www.engr.sjsu.edu/bjfurman/courses/E10/E10pdf/Structures_Stiffness.pdf

Check out pages 12, 13, 14. I'm not arguing for either side; I just Googled and found this appropriate.

Interesting, thanks for the info. If I had the time I wondered if I inputed the same outside dimensions instead how would the results turn out But basically this is comparing volume/weight change together with increasing outside/external dimension. Not the same as our line of discussion where the dimensions (outside) is the limiter or 'the shape is the same'.

However I sorta assumed from the start that was an equal external dimension (words to that meaning) assumption. Meaning the outside shape/size is the same and any reduction is more on the 'taking off' kind not on the 'redesign until different' kind I think for the same shape/size my earlier assumption is correct.

But interesting enough for this case (in attached pdf file) a redesigned material can result in a greater strength. By playing with the 'lever arm' effect (moving more stuff further from neutral axis) the capacity will be increased. This is basically just a practice in improvement in efficiency. However in real life one has a little heaache in how to fully utilise the bending capacity since hollow sections are at risk of concentrated deformations and etc so care must be taken. I-beams for example if you designed your own instead of relying on the time tested standard data. Too thin a web will result in concentrated buckling and too thin a flange will result in low bend strength. However compared to a solid piece of steel of same external dimension you'll find it's stronger and heavier and runs very little risk of concentrated buckling.

In my tests the limits of dimension are the same. This would be the case in skeleton liners unless the thickness is increased. Strictly speaking it is most likely for a slight increase in thickness they'll be a net increase in handle flexural strenght?

 

[Cotherion]

I would like to know how did they determine the location/size of the holes on the liners? Is there any engineering computer analysis based on typical (and maybe not-typical) loadings. Finite element analysis of some sort.

Or was it trail and error? Either way I normally practice 'fix it when it breaks' and so far Spyderco's track record are good

(Back on track the main gripe is how the holes accumulate grime/dust/gunk and my problem is constantly screw/unscrewing will result in eventual damage. Air compressor does not work all the time and who actually has industrial grade air compressor handy nowadays )

 

[3Guardsmen]

(Back on track the main gripe is how the holes accumulate grime/dust/gunk and my problem is constantly screw/unscrewing will result in eventual damage. Air compressor does not work all the time and who actually has industrial grade air compressor handy nowadays )

Those cans of compressed air (which I use on my knives), meant for cleaning computer equipment and keyboards, haven't worked for you?

Regards,
3G

 

[Cotherion]

Those cans of compressed air (which I use on my knives), meant for cleaning computer equipment and keyboards, haven't worked for you?

Regards,
3G

I don't use the can versions (don't know where to get them ) but I use the air compressor in my factory used to maintain the cleanliness of my machinery. I like them but I have to be ninja-secret about them since folders are illegal in my country and I do my cleaning at lunchbreaks

Normal dust, lint, stuff-which-is-dislogable and etc is fine but the problem is with the greasy sticky stuff. I use my Cara Cara (for example) as my beater. I cut, scrape, poke and in the machinery environment the stuff that gets lodged in between the holes are kinda greasy and thick (mixed steel dust and normal dust gets thick and disgusting). My industrial blower isn't good enough for that grime. (I use my folder secretly like take-out-use-then-keep-quick-quick way)

I tried the old hot water thing. It's ok but there is always the edges or the particularly stubborn grime that stays. I have a fidgety or obsessive (slightly ) attitude where I can't stand the muck left over. I almost always take em apart to clean them thoroughly. That leaves me with spoilt screw heads and threads. I replaced my screws with an old CS recon folder's screws.

My combo edge Cara (I have 2) that I got recently is with full liners (go figure?) and no problems with grime, only the lock area but that is fixed with toothpick. My gripe is not without basis and I use my full liner Spydie more often these days.


PS: Interesting to note that the lock isn't so bad even with grime. You just have to be aware how 'deep' the lockbar is engaged using your thumb. Not bad folders these Spyderco spin-offs.

PSPS: Strictly speaking I also like how the full liner Cara feel in hard grip. The full liners are solid and rigid with much less flex. Less-flex=peace of mind. However I'm plenty sure that skeleton liners are strong enough. Case of Ultimate capacity being adequate but service capacity is less desirable in my picky and obsessed mind.

 

[jacktrades_nbk]

native 3, for example, with its pin construction, has no liners at all
i like it, and it seems strong enough even so
i would think that for breaking the lock, the lock pin would have to rip through the frn handle , in respect to the rotation of the blade, moving the rocker bar further to the back of the handle
so the lock strenght would be dependend on those 2 pins breaking the frn
my idea, anyway,
anybody would have an exact idea what would be its exact breaking point, with or without liners
anyway, i think that very high pressure must be applied to the back of the blade for causing a break or lock failure, liners or not liners

 

[Cotherion]

I think there is a point there where it's strong enough until failure (if occurs) may possibly be with the pin shearing instead of a linerless handle failing. Most likely the lockbar will either shear (the section where the 'tooth' enters the cavity in blade) or the little part of the blade near the cavity will shear. Quite possible. Unless someone does a Noss on it we won't know for sure...

However I own some CS Voyagers, Emerson Hardwear and also a Native all without liners (and also without screw pivots! I hate not having screw pivots...) and I honestly feel that they are Ultimately strong enough but lack rigidity for my peace of mind. Real solid rigidity that I can feel while crushing my full liner Cara in my paws and the handle has no give. My Manix has the most grip flex problems in this regard. Surprisingly the liners in my Manix is thinner and with holes compared to my band-for-buck Cara and that is mildly surprising.

My main gripe is the constant occurance of stubborn hard-to-clear-by-compressor gunk in the furthest nooks and crannies of my holey liners. I understand that Spyderco would have been easier off just leaving the liners whole but they were trying to fulfill the needs of a majority of users. That's how I see it fairly recently, and I think it ain't right to trash someone who is trying to do people a favor to get it thrown in the face somewhat

Therefore I decided to use my Native in gunky areas and the rest of my gang (most of mine are users... I really enjoy using good stuff) in non-gunk areas. Thinking back, I use to carry a CS AK47 in Aluminium before, it weighed my pockets down something frightful, a light, hard using knife like my Endura is a godsend to me back then. I carry an Endura and a Native now for less total weight in my pockets!

PS: I must apologise for being so long winded. There apparently isn't any short routes in the train of my thought and I'm constantly being de-railed in my thoughts...

 

[Sal Glesser]

When we break knives with no liners, more often than not, the failure is in the FRN.

When we break knives with liners, they're stronger, more ridgid and hold clip screws better, but then we get complaints about excessive weight and to leave out the liners.

When we make knives with liners, which are stronger at holding pins and screws, and we skeletonize the liners to deal with the excesive weight issue, we get complaints about gunk storage.

It's a good thing we make knives with all three methods.

At this time I'm still listening.

sal