Solution to the off-center blade?

fulloflead

fulloflead

Joined
May 3, 2002
Messages
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Ya know how SO MANY liner locks have their blades off-center in the handle when they're closed because the lock pushes the blade over to the other side?

Well, I was noticing that my Al Mar knives don't have that problem, EXCEPT the Nomad.

NOW, take a look at this picture:

[Left to right: SERE 2K, Shrike, Nomad]


Notice anything interesting about the locks?
Notice anything different about the Nomad?

The other two have a relieved area behind the locking bar so that there's some space behind it when the knife is closed instead of that bar being pushed right up against the inside of the scale. The Nomad doesn't have it.

Genius.

More makers should do this.

.
 
In some situations it is the detent ball that is doing the pushing from where it is mounted in the lock because the ball sticks out just far enough to make the blade physically move it when you close it down. If the lock is all the way to the side and the detent sticks out that far into the blade space something has to give so the blade is the logical choice.

Most of that can be eliminated by a proper sized washer on the detent side. Theoretically if the washer thickness is the same as the amount of the detent ball sticking out then there should be ample room for the blade to sit perfectly centered. If however the washer was say a .10 thickness and the detent ball stuck out .30 then it would push the blade to make up for the difference. Hope that makes sense.

I use a phosphorus bronze washer most of the time on my folders. Doesn't matter what thickness I choose so long as I use the washer to set the detent ball in place. If say I use a half mm thick washer, then I drop the detent ball in the predrilled hole I have drilled and I get my washer and place it so it surrounds the ball sitting there and I place my flat punch on the ball and tap it. The washer keeps the punch from going down any farther and what you end up with is a detent ball sticking out the same height as the thickness of the washer. This should allow the blade to close centered without the need for routing a recess area into the side of the handle although I guess doing that would meet the same end result. Six of one half dozen of another I guess.

STR
 
STR said:
I use a phosphorus bronze washer most of the time on my folders. Doesn't matter what thickness I choose so long as I use the washer to set the detent ball in place. If say I use a half mm thick washer, then I drop the detent ball in the predrilled 1/16" hole I have drilled and I get my washer and place it so it surrounds the ball sitting there and I place my flat punch on the ball and tap it. The washer keeps the punch from going down any farther and what you end up with is a detent ball sticking out the same height as the thickness of the washer. This should allow the blade to close centered without the need for routing a recess area into the side of the handle although I guess doing that would meet the same end result. Six of one half dozen of another I guess.

STR
Click to expand...

Clever.

I guess factories can't be that careful.
Now, if it IS done WRONG, having that space behind the locking bar gives enough fudge-factor to make up for it.
 
Correct.

Most of the folders I have seen with the routed out section in the scales do not have washers in them.

I can think of several folders that I have seen that have this recess and I've done a couple of my WhittleJack folders this way when I made them without washers because the blade is made to rotate on steel next to steel so the blade is actually flat on the liner and the lock. Before the days of titanium you didn't see many people fooling with washers because you could get a pretty smooth action from a polished steel blade against a polished stainless lock and liner. Over time it would break in usually and of course us old timers never hesitated to use some oil if it helped to smooth things over.

Titanium has a tendency to gall or stick against dissimilar metals and as a result it doesn't work very well as a liner or lock material unless you use a washer between it and the blade. Some have managed to anodize it to a harder surface to make it smooth though but even that can wear off so washers are usually par for the course on titanium lined knives. Ti is also favored for liner locks for this galling effect because the lock sticks to the blade better and is less likely to be forced off or 'defeated' under pressure than a same position and same angled stainless lock. Ti is also liked because when the lock gets loose and needs adjustment a punch and good tap can squish it out just enough to take out any play in the lock that develops over time. Doing this to hardened steel can be a pain if not impossible. Even still I like stainless better because it doesn't indent as easy as ti but that is another story.

So, back to topic, in the case of a non washered steel against steel situation the routed section for the lock to push back into the scale is necessary because you need to route a small section of the handle scale out to the same depth or slightly greater than the detent ball sticks out on the blade side.

Again I hope that makes sense. Sorry for the ramble. I edited out a large part of what I originally said here because after rereading it it even confused me> :eek:
 
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