Spyderco Watu CPM20V Compression Lock Knife

Both the Tangram and the Griffin I have do that -- but there's a problem doing that that you can spot straightaway when you see pics of their button assemblies, disassembled: [image] [image] Namely that the plunge locks 'neck down' halfway through in order to provide a channel for the knife tang to slip through when opening and closing. So rather than having a spring that extends some distance up the axis of the button, it's only in the bottom quarter or so of it, making it less of a smooth assembly and more of a 'man balancing on a ball' sort of thing that leads to wobble. In the Griffin it's an even coil you can't see because it's nestled in the base of the assembly, and the only reason it doesn't wobble is the tight tolerance -- in the Vector the spring is flared at the base which accentuates the teeter-totterness of the entire ensemble, but you don't really notice because it's a small knife.

yeah, maybe its because for liner and frame locks, all you need is a cutting disc, whereas a button lock you need a metal lathe, which cost more time and money to operate and make the buttons to tolerance, on top of assembly costs. i remember the process for making a liner lock by a custom maker and all he uses is a dremel, drill and a jig for the the lockface on a grinding wheel. just spitballing here too. but on that note, if they make the button hollow to begin with, and then put a cap on it for your finger, then couldnt they get away with putting the spring inside the button rather than on the outside, making assembly easier while maintaining rigidity of the lock?

I'd love to hear someone inside the industry chime in, too. Most automatics are plunge locks, right? Automatics are everywhere these days - what's so hard about building one without that additional spring? Like you say, it seems simple -- yet lots of evidence suggests that it's hard to get right. The Ferrum Forge guys talking about how they needed to get the plunge lock just right before they rereleased the Mordax -- which is regularly out of stock at Drop even though it's probably $40 too expensive. The fact that Protech is only able to release miniscule runs of their own manual plunge locker, the Malibu, compared to their autos, despite clear demand for them -- yours truly has been looking for one for months now and they always sell out before he finds them in stock anywhere. Real Steel has been talking about rereleasing the Griffin since at least 2018 but it keeps hitting the back burner. Plus, look at the market. Going to BHQ's folding knife selection as a quick and dirty breakdown: 6800 frame locks 4689 liner locks 1319 back locks 323 plunge locks (most of which are actually automatics, not manuals) That's a hell of a drop off. We are a push-button kinda race, humans, so this discrepancy is hard to explain just based on the face of things. As far as other fidget friendly lock styles like axis and compression locks? That is to say, in 2020, there are roughly equivalent numbers of button locks - a non-patent-protected, non trademark protected lock that has been glamorized as part of the traditional switchblade knife for over a century - on the open market than there are compression lock and axis lock knives combined even though those latter both have trademark protection and the compression lock still has patent protection. So what gives? If I had to guess based on my own limited experience fiddling around with plunge locks, I would say it's a combination of three things. The first is that it's probably hard to find that magic tolerance where the plunge lock works smoothly but it locks up without either wobble in the button or play in the blade -- maybe it's easier with the automatic spring bracing the pivot, maybe that helps eliminate what would otherwise manifest as wobbly construction, and with a manual it's just got to be perfect. Second is that while I'm sure they're just making the buttons out of round stock, they do have to machine the lockfaces into the tangs and it's gonna be easier to machine a flat lockface than a perfectly circular one. The third is that having had a few button locks all the way apart I can tell you that they are a cast iron bitch to reassemble correctly, you want to have like four hands to do it and you swear a blue streak the entire time. And it's mostly the button assembly that's the root cause. That spring is basically the same spring you see in ballpoint pens, and it just loves to go flying places when you're trying to assemble the knife. Keeping the button assembly straight is worse than having a stop pin that wants to keep falling out of joint when you're trying to fit the frame back together. The E series Griffin just about took a year off my life trying to fit it back together. Fiddly plus precision tolerances equal massive pain in the ass. Now, I know in a factory they're putting it together on a jig that makes it a lot easier -- at least I hope they are! I hope they're leveraging machinery and tooling to make it all scalable. But I wouldn't be surprised to learn that knife makers have to spend a lot more hands time making plunge locks than frame or liner locks, even with a jig and specialized tools and whatnot - that and I bet it takes a bit more senior of a laborer to get it right. All this is me just spitballing though and I don't know what I don't know. If anyone from the industry wants to shed some light on the reason plunge lockers are so comparatively rare compared to liner and frame locks, I'd be grateful and I think a bunch of people might find the reasons interesting.