Is "slight" blade play/wobble normal on slippies?

marcangel said:
I couldn't quote everyone here since I'm replying to multiple posts.

1) SAKs are built in layers, and the whole knife is held together with brass pins and rivets which can be removed (with great difficulty, unless you have a special tool). The rivets hold the WHOLE knife together, and when removed you get the aluminum layers and all the tools from the knife separated, including the blade. There is no "separate" pivot for the blade and if memory serves me correctly, there are three brass pins on 91 mm models that hold the whole thing together. The scales are pressed onto the rivet heads and pins and are held by friction. The pins are not "spun on" but pressed in VERY tightly, which is one reason why there is virtually no blade play.

2) Try to slide the bill between the blade and the liner, whatever it may be.

3) Handle material should have NOTHING to due with blade play. The mechanical unit we are looking at is the blade, pivot, and liners/bolster/frame. Handle material is pinned, epoxied, inlayed, glued or whatever to the frame or liner and is considered a separate mechanical unit.

4) Not all "tacticals" are screwed, almost all production pieces are, but some handmades are pinned. I have a Prinsloo that is pinned, and was actually hoping it WAS screwed, since it has...guess what...

BLADE PLAY!:grumpy:

5) Blade play can be found in any style of knife and is not the nature of the slippie beast or anything else. It simply has to do with the tolerances (or more appriately LACK of desired tolerance) of the blade/pivot unit.
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You have made my point, it is an apple to oranges comparison. On a bolstered knife the pins cannot be pressed in VERY tightly, they are peened into a countersunk space. So saying Victorinox can make knifes without blade play so ___________ other company should be able to also is not valid. You could argue that a bolstered knife should not have any blade play if it is constructed correctly, but comparing them to SAKs is not valid.
 
How the pivot of any folder is put together is really irrelevant, be it pinned, screwed, framelock, liner or slippie. Blade play is caused by suboptimal tolerances of the pivot mechanism. Period. It is not unique to slipjoints or any other type of folding knife. If you, personally are O.K. with blade play, so be it. The point is that if 1 manufacturer can produce millions of folders that don't have a defect, well everybody else probably should be able to that as well.

I can assure you that Tony and Reese Bose, Joel Chamblin, Ruple, Kious, Osborne and a TON of other makers don't let a knife with blade play out of the shop. That is not to say I don't appreciate the time and effort involved in getting it right. I do. Firsthand. I've built a number of slippies and lockbacks from kits. Let's just say that if I ever build another kit knife, it will be screw pivot linerlock or framelock. Interestingly though, if you talk to makers directly, almost all of them will tell you that pinning the pivot joint is easier than getting the precise tolerances of a linerlock.
 
marcangel said:
....
3) Handle material should have NOTHING to due with blade play. The mechanical unit we are looking at is the blade, pivot, and liners/bolster/frame. Handle material is pinned, epoxied, inlayed, glued or whatever to the frame or liner and is considered a separate mechanical unit.

....
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Thanks for the additional information..it was helpful.

On your point #3, I wouldn't expect anyone that has not made slip joints with natural handle materials to readily understand this annoying aspect of knife making. Even after somebody that knows a thing or two about knifemaking told me it would happen, I politely said, "no way!" "Yes way" has been my experience.

The point I was ineffectively trying to make before is this; a knife made with natural handle materials and with the close tolerances, FnF, and lack of blade play that many knife enthusiasts require is extremely susceptable to changes in the way the knife behaves when opened and closed. This can happend do to the handle material expanding lengthwise and putting pressure against the bolster where the handle material and bolster meet. The effect of expansion is even worse on knives with bolsters and caps or double bolsted knives such as a 3 blade stockman because the slab is captivated between those metal pieces.

Think of the bone as a press pushing against the end of the bolster. There is a "pivot point" where the bolster and liner meet which is an area of relative weakness in the handle assembly. As the bone expands, the bolster acts as a lever which pushes the other end of the bolster into the space where the blade travels and creates a pinch on the blade. Granted, the movement is very small but when the tolerance is .001" to .0015" of gap for the blade to be able to rotate smoothly, it doesn't take much movement to quickly take over that gap and begin pinching the blade.

Has anyone here ever had a bone handled pocketknife go through a wash n rinse? :D They don't work too good after that but if you let them dry out and give them a good lube job, they will usually get their snap back.

Cutlers know that covers have the potential to either cause blade pinch or blade play, depending on which way the handle material moves. If at the factory, a cutler assembles a knife with "wet covers" and gets it adjusted to work perfectly and later it drys out, you got yourself some blade play. If the cutler leaves a little gap between the bolsters and "dry covers" and they later get wet, the expansion won't create as much of a problem but then you have an unsightly handle gap at the bolster that nobody likes. Cutlers know that covers have to be thoroughly dry and precisely cut and positioned for the knife to continue to operate properly but, as they say, stuff happens...or something to the effect.:D

Natural handle materials are an integral part of the mechanical functionality of slip joints. By all means, if you don't like the amount of play in a factory made knife, you should talk with them about getting it repaired or replaced to your satisfaction.
 
Just an aside on the Victorinox sak's. A few years ago I read in a buisness magazine where Carl Elsner and the board made a good descission. They took a record amount of money from the general proffits, went without thier bonus and pay hikles, and put the money into all new machines. They bought the lastest most high tech high speed CNC production machinery, so the Victorinox knives are made in what is probably the most automated factory in the world. Elsner stated in the article that they had to do this to remain competitive in todays market.

With the exeption of a hand made knife from Tony and Reese, or Joel, you won't find a knife made with production and QA like Victorinox.
 
marcangel said:
How the pivot of any folder is put together is really irrelevant, be it pinned, screwed, framelock, liner or slippie. Blade play is caused by suboptimal tolerances of the pivot mechanism. Period. It is not unique to slipjoints or any other type of folding knife. If you, personally are O.K. with blade play, so be it. The point is that if 1 manufacturer can produce millions of folders that don't have a defect, well everybody else probably should be able to that as well.

I can assure you that Tony and Reese Bose, Joel Chamblin, Ruple, Kious, Osborne and a TON of other makers don't let a knife with blade play out of the shop. That is not to say I don't appreciate the time and effort involved in getting it right. I do. Firsthand. I've built a number of slippies and lockbacks from kits. Let's just say that if I ever build another kit knife, it will be screw pivot linerlock or framelock. Interestingly though, if you talk to makers directly, almost all of them will tell you that pinning the pivot joint is easier than getting the precise tolerances of a linerlock.
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I am confused, what do custom slipjoint makers have to do with production slipjoint makers (again, apples and oranges). Also, I am saying one type of manufacture is harder to get right (if you consider no blade play getting it right) than another, so again, apples to oranges. If one manufacturer made millions of peened, bolstered folders without defects than your point stands, if not, then it doesn't. It can be argued a company like Case should produce knives without blade play without comparing them to Victorinox. You consider it a valid comparison, I do not. It looks like we will have to agree to disagree.

I, personally, think some of the American traditional production slipjoints I have owned or handled are not up to snuff. This they could fix by better quality control in their manufacturing process, not by adopting a different one.
 
I was going to say that. Comparing hand made customs to factory knives isn't a good comparison.
 
Knifehead, you are correct. Natural materials can certainly have an impact on the pivot. I thought we were taking about NEW knives. Obviously, if a knife is exposed to the elements or used all bets are off. I was using Victorinox as an example of a company that produces MILLIONS of knives and gets it right, everytime. And if they don't, just send it back. In my opinion it really is no different, because a pinned slippy is going to have at least 1 other pinned joint as well.

I can think of several other companies that have consistently produced folders with 0 play and used pinned joints. Moki (also the OEM for Al Mar, Fallkniven, Haller-Premier and sometimes Spyderco) has no blade play. Yes they make slippies too. Queen comes to mind as well. The point is, it's not supposed to be there. If it's OK with you, fine.
 
marcangel said:
How the pivot of any folder is put together is really irrelevant, be it pinned, screwed, framelock, liner or slippie. Blade play is caused by suboptimal tolerances of the pivot mechanism. Period. It is not unique to slipjoints or any other type of folding knife. If you, personally are O.K. with blade play, so be it. The point is that if 1 manufacturer can produce millions of folders that don't have a defect, well everybody else probably should be able to that as well.

I can assure you that Tony and Reese Bose, Joel Chamblin, Ruple, Kious, Osborne and a TON of other makers don't let a knife with blade play out of the shop. That is not to say I don't appreciate the time and effort involved in getting it right. I do. Firsthand. I've built a number of slippies and lockbacks from kits. Let's just say that if I ever build another kit knife, it will be screw pivot linerlock or framelock. Interestingly though, if you talk to makers directly, almost all of them will tell you that pinning the pivot joint is easier than getting the precise tolerances of a linerlock.
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+1. A loose blade is a defect. Blade play = loose blade = substandard.
 
I have had many production slipjoints that had zero side to side blade play & after some useage,a lot of them developed play.Some more than others

I have have & have had many custom slipjoint knives from a great array of makers that have had some degree of detectable bladeplay.

I also have had a few from both categories that had none & developed none after a fair amount of useage

Bob Dozier once told me,"Stuff wears out"

-Vince
 
I'd like to add, I have had many really old knives with blade play so bad,they flopped in the breeze,worn down blade profiles,too.They still cut stuff pretty darn good though

I never saw any recent made knive,custom or production worn like those,either

Here's a thought,put your knives in a case to look at,they'll never get worn out or get bladeplay

I think you'll enjoy them more to carry & use them,no matter what the outcome. Surely a knife that stays tight after alot of cutting is well made
-Vince
 
Blade play has no effect on how a slipjoint performs. If I buy a knife online and it has no blade play I consider myself fortunate.My NYK whittler has zero blade play and it walks and talks like the best. My Case 6347 has a bit of play in the main blade. This used to bother me. Not so much these days.I do have a limit though too much is a defect. A little bit is just tolerancing specs and it's to be expected.It's not just the thickness of the spring and blade, but the hole size too. My guess is a blade that is .001 under the spring thickness will have minimal play .0005 each way. .0005 tenth under would be undetectable. Out of all the knives I've owned over the years, I would say 10% or les had zero blade play on them. I currently have 7 if you count my super tinker and soldier. the other ones ar my NYK, my two Mooremakers and my old Camco. go figure, three out of the seven are Camillus. Wait, one more, my Remington Bullet.(another Cammie), and my Case mini hunter. I sent it back to the factory for repair and it came back mint.
 
Most of the blade play that I have seen in new production slipjoints was due to the gaps between the springs and liners or between the liners and bolsters. Pivot wasn't peened right. If they wobble when they're new, a few months of use is going to make it real sloppy.
Greg
 
BJE said:
Alot of people on here must have a VERY difficult time finding a knife they are willing to keep if they accept no blade play. Some of my favorite knives have at least a little play. I can't even feel a little play when I actually use them, only when I wiggle the blade, so why is this such a big deal? Alot of blade wobble is a bad thing, but I don't see the harm in a little unless it is a very expensive peice or a custom.
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Nope, I DON'T find it difficult at all finding knives with no blade play. Quite easy actually. Buck, Case, Schrade (the former) & SAK, to name a few.
 
I agree, I have no trouble finding slipjoint knives w/o blade play. Of the slipjoint knives I listed w/o play, 4 custom, 4 case, 4 queen, 2 swiss army, one DoukDouk, one Martin, one Northwoods and two leatherman, eleven were bought sight unseen.

I have put blade play in knives through abuse and use (>5years), but that is readily fixed by the methods previously mentioned. Per stories on this forum, Buck, Case and Queen all consider blade play a repair covered by warranty.

Hey it's a "slipjoint" not a "slopjoint" :)
 
I like NirreBosse's description of what he deems acceptable; if he can feel it but not see it then that's acceptable blade play to him. Sounds very reasonable to me.

I have an idea for another thread; Blade rubs in production multiblade folders - Stop the madness!!! :D
 
From this point on, If I buy a new production or custom knife, I will return it if it has any blade play.
 
KnifeHead said:
I like NirreBosse's description of what he deems acceptable; if he can feel it but not see it then that's acceptable blade play to him. Sounds very reasonable to me.

I have an idea for another thread; Blade rubs in production multiblade folders - Stop the madness!!! :D
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CHAFING...OH GOD HOW I HATE CHAFING!!:mad:

But I'll take chafing anyday over bladeplay!

Look, I made a rhyme!:D

Chafing IS acceptable, trying to EXPLAIN that to somebody who doesn't know alot about knives, and slippies in particular is like trying to explain why the sky is blue to a 4 year old!:eek:
 
My Queen made slipjoints tend to be tighter than my Old Timer slipjoints.

Actually the overall quality is nicer on my Queens.


A small amount of play is ok, at least in my book.
 
Just throwing in a 2 cents to this thread on "pins". Here are photos of sectioned Buck slipjoints thru the ages. I like a perfect blade to handle attachment like the next guy. Not much wobble, but no scaring of the blade tang by opening action. Clickable photos to reduce space on thread for those not interested. I did the sectioning by epoxying everything in blade well and grinding and polishing till I was tired of it............. 300Bucks

First 300series Schrade contract Buck slipjoints. 66 to 72


Second model 300 series, Contract with Camillus 1971 - late 90s note swelled ends


Buck in-house method. 1990 to present, intergal liners


Heres how Schrade did the liner for assembly. This required complete dis-assembly for repair......and let me tell you, three hands would have been "handy".
 
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