ZT 0452 lock up

Argumentative bulls..t was the first grenade lobbed, my friend, anyway we can just agree to disagree because this has lost anything that might be productive. Have a good evening :)
 
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PURPLEDC said:
Do any of those knives have curved lockfaces? A radius to the lockface is a huge factor in whether this will happen. And the radius can be so slight that its hard to spot with the naked eye.





Here is the thing, the guys who use their knives hard and they find this to be an issue that is fine. I can see it being a less than desirable trait. The problem though is not everyone uses their knives that hard. And this thread has all ready shown that people who never had a problem with their knives after months if not years of use are reading this thread and going to knives they never had a problem with and intentionally forcing the lockbar and stressing it to jam and going "oh, it is defective" yet their knife would never have exhibited this trait unless they read this thread and went screwing around with it. To me its kinda like a guy who gets disappointed after seeing the cold steel videos showing their favorite knifes lock failed at 300 pounds rather than cold steels lock failing at 500 when they may never even put 5 pounds of pressure on that lock in its lifetime to begin with. Also reminds me of guys who get miffed to find out that their car has speed limiter at 105 mph when they dont every go above 70.
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True but some locks start sticking bad after something like making a feather stick, a pretty tame "harder" use For a folder. Sure not everyone will experience it but that doesn't mean it's not important. I just had a recall on the passenger airbag in my car, never had the bags deploy but it was still good to know (and fix). If you don't use your knives "hard" then blade steel should surely be irrelevant as well. But it's not right? ;)
 
kniferbro said:
True but some locks start sticking bad after something like making a feather stick, a pretty tame "harder" use For a folder. Sure not everyone will experience it but that doesn't mean it's not important. I just had a recall on the passenger airbag in my car, never had the bags deploy but it was still good to know (and fix). If you don't use your knives "hard" then blade steel should surely be irrelevant as well. But it's not right? ;)
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That's a whole other... thing. You'll probably find a few people to argue that point too, without looking real hard. I think it does, but some... not so much, anyway.
 
Maybe some of the harder steels, i.e. M390 or ZDP-189 might accelerate the process but I would agree that it would not be that much unless you sit round and flip the knife 100's of times per day.
 
Sikael said:
It sounds like using a slightly radiused lockface could be a good way to go. Why wouldn't most makers do that?
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well any curved lockface can potentially develop lock rock. Because the prevention of the slippage is done by that curve. So as the lockbar wears and it can only go to that one point in the curvature of the face lock rock can take place. Not always but it can. And that is the dragon chasing of knifemaking. You are constantly trying to prevent potential problems. Its just my personal opinion but I dont think curved lockfaces are a problem when paired with a hardened lock bar insert as the steel wont wear nearly as fast as raw Ti and it can be replaced if need be. But lock rock is usually what is cited as a reason certain makers prefer a flat face.

jill jackson said:
There's a pretty good angle on the ZT's blade face. Do you think the CF handle and long Ti lock bar flex enough under pressure to allow the lock bar's face to just slide on over to the other side?
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my theory is that when pushing on the lockbar anything that has the potential to flex in that situation is flexing. Maybe a bit from the lockbar cutout as that all ready has a bend to it and maybe its increasing as you increase pressure. Not enough to yield it but enough to allow for the lock to slip. But I really cant say for sure. But I do think there is something to be said for having an extremely long lock bar. And my 0900 is much harder to get this issue to present itself. So I often wonder if a short lockbar is that much more rigid why so many makers choose to make is as long as they do. Honestly its all theory with me right now and very little ability to figure anything out as I dont have one of these anymore to try and figure it out. And I dont currently have a knife with similar set up to try and use that either.
 
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I made my case in msg #54. Reading all this is making me dizzy. [emoji57]
 
Attention Fanboys and Haters alike... If we have to come in here and baby sit anyone, it's not going to be pleasant. You've already been warned. This is a knife forum, first and foremost. We discuss knives, and their related attributes, flaws, perceived flaws, likes, and dislikes. If you for whatever reason cannot contribute to the discussion in a mature and productive way without getting all butthurt, then the best thing to do is log out and go do something else. If you persist on discussing one another, taking jabs and being abrasive then be gone.

Sikael said:
It sounds like using a slightly radiused lockface could be a good way to go. Why wouldn't most makers do that?
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Everyone has the "best" way to make a liner lock and frame lock. Can't make everyone happy. Emerson has a good description of his formula. The "angle" is something that is not discussed in great detail by any manufacturer from what I've seen. That being said, I hope they don't disco this knife before I have the chance to buy one. You never know though.
 
Look like to me that it has been let go and we are now discussing the difference btw harder steels and how they react to the Ti lockface.
 
Anyone who knows me knows I am no fan of ZT, but I saw this knife and simply had to have it and have never been more pleased with a knife purchase.
I have carried and used it every day at work and play for the past three weeks and the lock has not moved since the day I unboxed it. Of course I don't sit there and intentionally try and force the lockbar with all my might like the guy in the video though...
 
I never had a lockbar move all the way over while I was using the knife on any of my knives from any manufacturer.I have never intentionally tried to push any of the lockbars on my knives over on purpose either.The only problem I have ever had with lockup of a frame lock was a little lock stick on a very low serial# 0560.I have not had lock stick on any models with a steel insert. I am not going to try to push my lockbars on any of my knives over on purpose because the all seem to be functioning properly and are 100% reliable.Those of you that seem to feel that you have a defective knife should send it in to warranty and please post the outcome after you have your knife back.All is well that ends well.....
best,
salmonkiller
 
Mine doesn't move. It ain't from the first batch tho. Detent firm but good. First batch specimen was lemon status.
 
Here's my contribution to this thread.

1) I had a 560 whose lock bar I can easily push in without much effort. But at that time, everything was wonky as it would snap open as I take it out of my pocket. I could even have it in the closed position, hold it in my hand and snap my wrist without effort and the blade would come flying out. At that time, I didn't know what to do so I sent it in and it came back solid and with the steel lock bar insert. I suspect now that screws may have gotten loose? I share that as maybe something you can check with your screws to see if they've loosen up.

2) I looked at my 452CF closer tonight with a loupe. After the initial issues I was having such as I didn't like the lock bar scraping, it operates pretty well now. I got rid of the feeling of the lock bar scraping with just a dab of chapstick. I haven't needed to reapply since.

On normal flipping, the edge of the lock bar is even with the edge of the blade. If I try to force it in, it will only go in about 1/32" past the edge. I certainly can't push it all the way to the fiber carbon side. If it happened to me, I would be dismayed.

Mine is SN # 2176
 
Here's the lockup on mine. Left is the "normal" lockup -- flipped open, and then given a hard grip in hand, just to move the lockbar to where it might end up under normal use. Right is me deliberately trying to force the lockbar to the other side by specifically pinching the lockbar and opposite scale and pressing hard.

Lockup is solid (no lock rock / blade play) in both cases. In the latter case, the lock does become more difficult to disengage, but is still possible. Early or late lockup is fine by me as long as it is a solid and secure lockup. Should the lockup ever wear such that there is lock rock or it no longer stays locked when open, then that's what warranty service is for. That's just my take on it...

Deliberately forcing the lockbar over isn't unique to my 0452CF. I can do the same with any of my framelock or linerlock knives if I make a specific effort to force the lockbar over.

I've got SN #0444.

ZT0452CF_lockup_normal-forced_800x500.jpg
 
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I can force any of my liner lockers and any of my frame locks, over some with finger pressure, but it's just that, some is all not all the way to the non-locking side. It just seems to me when a lock bar can be forced over that far, (with finger pressure) things just aren't as tight and well fitted as they could be. Maybe it's fine and ZT considers this to be normal, IDK I sent them a link to this thread and never heard anything, so far. I doubt they will issue a statement here being they left for good it seems.
 
flarp said:
Here's the lockup on mine. Left is the "normal" lockup -- flipped open, and then given a hard grip in hand, just to move the lockbar to where it might end up under normal use. Right is me deliberately trying to force the lockbar to the other side by specifically pinching the lockbar and opposite scale and pressing hard.

Lockup is solid (no lock rock / blade play) in both cases. In the latter case, the lock does become more difficult to disengage, but is still possible. Early or late lockup is fine by me as long as it is a solid and secure lockup. Should the lockup ever wear such that there is lock rock or it no longer stays locked when open, then that's what warranty service is for. That's just my take on it...

Deliberately forcing the lockbar over isn't unique to my 0452CF. I can do the same with any of my framelock or linerlock knives if I make a specific effort to force the lockbar over.

I've got SN #0444.

ZT0452CF_lockup_normal-forced_800x500.jpg
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It's great yours is that tight, mine and some other people's 0452's go all the way over to the CF scale when pressed like that (and stick badly). Would you still be happy if yours did?
 
RevDevil said:
(...) Everyone has the "best" way to make a liner lock and frame lock. Can't make everyone happy. Emerson has a good description of his formula. The "angle" is something that is not discussed in great detail by any manufacturer from what I've seen. That being said, I hope they don't disco this knife before I have the chance to buy one. You never know though.
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Given its popularity, I doubt ZT will discontinue the 0452CF, and I really hope they don't. The Sinkevich designs, particularly the original 0454 and Russian G-10 variant, are some of the most original and attractive production knives available... or unavailable.

My experience with the 0452CF is almost entirely positive, beyond the slight scraping of the tang between the lock-up and the point where the detent makes contact; not a major concern, and easily addressed. If this were a I knife I didn't like, I wouldn't care that much about a few anomalies. ZT is a great brand, and Dmitry Sinkevich is a designer/maker whose work I really admire -- the 045X models are the only Sinkevich knives you'll find for less than 1800$, with the exception of the Fantoni C.U.T. and the Kershaw version of the Nura (which would have been better as a ZT model, IMO).

I'm hoping this is something they can address with a slight 2nd generation adjustment of the lock-face angle (there's not a lot of room for play -- I think 5 - 8 degrees is the consensus on the range of safe, reliable angles, IIRC), or maybe even the interior travel-stop that Sinkevich and Shirogorov models use... but it's never simple, I know. The 'radiused' (radial?) lock-face might be another possibility. I don't think ZT use any kind of rounding on the tang lock-face, at least not that I've seen, and I'm not sure what kind of negatives are associated with improper execution, like slippage -- a much more serious lock failure.

Even without any best case scenario 'next-gen fix', your chances of getting a defective knife are still pretty slim, and most should hold up to hard-use.
 
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jill jackson said:
I can force any of my liner lockers and any of my frame locks, over some with finger pressure, but it's just that, some is all not all the way to the non-locking side. It just seems to me when a lock bar can be forced over that far, (with finger pressure) things just aren't as tight and well fitted as they could be. Maybe it's fine and ZT considers this to be normal, IDK I sent them a link to this thread and never heard anything, so far. I doubt they will issue a statement here being they left for good it seems.
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I think everyone who is aware of the history here knows you likely will not get an answer to your question and it will be a cold day in hell if ZT posts such an answer here.

Honestly, just stating the problem over and over with pictures and what not will not answer anything. Have you filled out a warranty form and will you send the knife in today?
 
craytab said:
I think everyone who is aware of the history here knows you likely will not get an answer to your question and it will be a cold day in hell if ZT posts such an answer here.

Honestly, just stating the problem over and over with pictures and what not will not answer anything. Have you filled out a warranty form and will you send the knife in today?
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I will if ZT tells me it's faulty and they will make it right. Otherwise why bother if they consider the lock within spec.
 
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