Stop Pin Modification to Eliminate Vertical Blade Play

M

Mme09005

Joined
Apr 7, 2020
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So I have been struggling the past few weeks with a few of my knives that have a very tiny (and I mean ever so slight) vertical blade play, known commonly as Lock Rock. I originally thought I could get over it, but couldn't, it's eating my brain.

I set off first on finding the cause and I believe that it is excessive tolerance between the linerlock and the stop pin. I stuck a very small slice of post-it note paper onto the stop pin, opened up my knife as I normally would, and there it was, the perfect lock up. Rock Solid in all directions. The first thing that came to mind was, a bigger stop pin would be the solution here. However, I do not have capability to make one or know where to order one for this particular knife, Civivi Governor.

I started experimenting and came up with a fairly good solution that uses super glue and a rubber band. It is not pretty, but it got the job done. I dropped a dab of super glue onto the stop pin and stuck a rubber band ontop. Once it was fully dried, I peeled back the rubber band and was left with a nice rubber coated stop area on the pin. Opened the knife a couple of times, and that was it, perfect lock up. The rubber layer on the stop pin deflects when the knife is opened and it takes up all the excess tolerance between the lock and the stop pin. This whole thing is also reversable with a little bit of acetone, so it was worth a shot.
 
Do you have any way to disassemble the knife to get the measurements of the current pin, and what the extension required to remove the play would be?
Best guess for the second part, I'd presume.
 
Yeah I did this with the whole knife disassembled, I would not risk using super glue on any part of the knife while it is still assembled, that stuff gets everywhere. I unfortunately don't have calipers or a micrometer to measure the dimension of the pin. The additional material needed on the stop pin to eliminate the play is literally the thickness of a sheet of computer paper, like .004".
 
Ah. I was hoping you could get a decent approximation of the size. Any idea about material?

I'd be willing to try and fab a few for you, on me, just to see if I can hit the mark you need
 
Not too sure about material, but a decent stainless steel that can take the wack from a D2 blade. My father probably has a caliper laying around, I'll see if I can grab it this weekend and get you some numbers, would love a custom stop pin!
 
I have some small stainless round stock, and I can also fab it from other steels. 5160, 15n20, and several other alloys. Just let me know and I'll be happy to try and make a few for you.
 
I just ordered a pair of calipers from amazon I'll post back here with the pin dimensions! Not sure what kind of material to use, something tough enough to not cause a flat spot easily but have enough corossion resistance. What do you think?
 
Corrosion resistance and that toughness would be maybe 440C stainless. Could also try 15n20 or 9260. An acid dip would prevent corrosion on non wear surfaces, but really some light lithium grease would be the preferred protectant for a carbon pin.
 
That sounds good! Will get you measurements! Can't tell you how much I appreciate this offer :)
 
If you would, send me the folder specs along with the measurements so I can try to see if I can locate any more in depth information about the part.

But you are very welcome. It will be a good challenge for me, doing a precision replacement part fabrication. I look forward to it. I have replicated a couple of small, precise pistol components before with success, and I quite enjoyed it.

Oh, and if you can include images of any contours on the ends or anything else that would be pertinent, that would be great as well. If possible.
 
The knife is the Civivi Governor, not sure if I can post links here to the knife retailer specs, but it is easy to find on google. I am not sure how to post pictures on here, but I can disassemble the knife and take pictures of the pin and the entire knife set up, its fairly straight forward.
 
Yeah there are two stop pins, one for when the knife is closed and one for when it is open. They are the same size.
 
I did that in hopes that one might be on the bigger side of the tolerance band, but it did not make a difference, same amount of vertical play can be felt with either pin in the blade stop position.
 
The pin dimensions can be found at the link below. The idea is to do a shouldered pin because if we increase the whole diameter the pin won't fit in the hole. Let me know if you have questions.

https://imgur.com/LI8Bx5I
 
Have you started machining the pins yet? I have a small change to make, I want to change the 0.140" dimension to 0.143".
 
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