Terzuola C19 Liner Lock “adjustment”

[MrGibson]

So I recently came across my old C19PS—which I thought I had lost in a move almost 20 years ago. Turns out it was just tucked away and forgotten in the move!

I haven’t carried this knife since at the latest 2000, and it’s got a fair amount of vertical movement when locked open. Normal wear and tear, I used this knife for everything!

My question is: I’ve read possible fixes include a larger diameter stop pin or increasing the bend in the liner lock or lengthening the liner lock with a well placed punch.

Honestly, the stop pin seems the least likely to cause future issues, but I’m a user not an engineer.

My questions to the forum:

1) the lock fully engages, and has room to go still, maybe the lock rock isn’t a big deal? Thoughts?

2) of possible fixes, does any with experience with such “fixes” have a preference?

3) assuming the stop pin is the way to go, where does one even get stop pins?

Thanks for your help!

[rangefinder]

I can't answer any of your questions except:

... 3) assuming the stop pin is the way to go, where does one even get stop pins?

And it's not my answer, it's from Michael Janich:

There's a brand of knife (not Spyderco) that uses unhardened stop pins that have a tendency to develop flat spots over time. I have had good luck replacing the pins in that brand with drill rod. Get a drill bit of the appropriate size and use a Dremel cut-off wheel to cut the base off to the appropriate length.

viewtopic.php?p=1667435#p1667435

[4077th]

Not sure about the C19, but early C36 Military models, first run Bob Lum tantos, and the Terzoula Starmate had "eccentric" pivots that will bring the tang closer to the lockbar if it's turned. Lots of trial and error. Lots of disassembly and reassembly. It would take the patience of a watchmaker to get one dialed in. I've never attempted to adjust one.

[apollo]

I can't answer any of your questions except:

... 3) assuming the stop pin is the way to go, where does one even get stop pins?

And it's not my answer, it's from Michael Janich:

There's a brand of knife (not Spyderco) that uses unhardened stop pins that have a tendency to develop flat spots over time. I have had good luck replacing the pins in that brand with drill rod. Get a drill bit of the appropriate size and use a Dremel cut-off wheel to cut the base off to the appropriate length.

viewtopic.php?p=1667435#p1667435

I have seen people make one from the backside of a drill.

[Brock O Lee]

I can't answer any of your questions except:

... 3) assuming the stop pin is the way to go, where does one even get stop pins?

And it's not my answer, it's from Michael Janich:

There's a brand of knife (not Spyderco) that uses unhardened stop pins that have a tendency to develop flat spots over time. I have had good luck replacing the pins in that brand with drill rod. Get a drill bit of the appropriate size and use a Dremel cut-off wheel to cut the base off to the appropriate length.

viewtopic.php?p=1667435#p1667435

Smart!

[MrGibson]

@rangefinder
@4077th
@Brock O Lee
@apollo

Thank you for all the tips/suggestions/referrals.

I was motivated by a combination of the idea referenced from @Michael Janich of using a drill bit, but because of the flattened area on the stop pin in the quoted piece.

I opened up the knife, rotated the stop pin 90°, and reassembled. No more vertical movement! There was a very a clear visually but physically undetectable flat spot. Rotating the pin, in my case at least, was a perfect fix.

So thanks again everyone for the comments!

[Brock O Lee]

Hey MrGibson, that was a quick and easy win! We should have known that rotating the stop pin could be a potential fix. It is suggested often for fixing lock stick on compression locks. On a liner lock, it makes perfectly good sense that a large enough flat spot on the stop pin could max out the lock travel, and cause vertical play.

Here's to a few more years of service!