ZT 0562CF blade wiggle between open and closed positions

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neonsteve

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May 8, 2014
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I just bought a used ZT 0562CF on the Exchange. The blade can be wiggled/rattled a tiny bit along its path of travel when it is between the open and closed positions. The blade does not move side to side at all but rather rocks back and forth a tiny amount, about 0.5 mm, at the blade tip. It is easily felt when jiggling the blade or shaking the handle. The movement can also be heard when placing the handle spine/back against a wood table and jiggling the blade back and forth.

I suspect it is the movement of bearings within their cage, but my ZT 0801 doesn't do this and I think they use the same bearings. Otherwise the movement of the blade is perfect. I am kind of new to higher end knives. I could probably post a YouTube video but hopefully my description makes sense enough.

Is this normal for the 0562CF, what could the cause be, and how should this be fixed? It doesn't affect use but it doesn't seem right. Thanks.
 
neonsteve said:
I just bought a used ZT 0562CF on the Exchange. The blade can be wiggled/rattled a tiny bit along its path of travel when it is between the open and closed positions. The blade does not move side to side at all but rather rocks back and forth a tiny amount, about 0.5 mm, at the blade tip. It is easily felt when jiggling the blade or shaking the handle. The movement can also be heard when placing the handle spine/back against a wood table and jiggling the blade back and forth.

I suspect it is the movement of bearings within their cage, but my ZT 0801 doesn't do this and I think they use the same bearings. Otherwise the movement of the blade is perfect. I am kind of new to higher end knives. I could probably post a YouTube video but hopefully my description makes sense enough.

Is this normal for the 0562CF, what could the cause be, and how should this be fixed? It doesn't affect use but it doesn't seem right. Thanks.
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If I am understanding you correctly (I'm not sure that I am) you are describing vertical blade play, also known as lock rock. That is not normal, and is unlikely to be something you can resolve yourself. I'd say send it back to ZT (or return it to the seller if you don't want to deal with it). Luckily my customer service experience with ZT has been stellar, and I have had my knives back in my hands with all problems solved inside of two weeks.

edit: If what you're describing is just a bit of looseness when moving the blade up and down when the blade is partially deployed, that's not uncommon in ZT flippers. I don't know what causes it, but I wouldn't worry about it.
 
It doesn't have anything to do with the lock, but I should probably try to understand better what lock rock means. From your description it sounds like looseness but I think it's excessive due to the feel and noise. I'll try posting a video tomorrow.
 
I'm a bit confused by your description. You seem to be saying that if the blade is not in the locked position, but has some minor travel as you are moving it between closed and locked open positions I'm not sure that's out of spec. Is the blade rock solid in the locked open position?
 
Let's say I move the blade to the 90 degree position, perpendicular to the handle. I can then rock the blade tip about 0.5 mm back and forth along the arc of normal blade travel. It feels like the blade is extra loose during that 0.5 mm. I can feel it when I shake the knife gently back and forth by the handle in this position (gently enough that I am not opening or closing the blade) and I can hear it a little bit too. When I move past the 0.5 mm then the normal amount of bearing friction kicks in. But this rocking back and forth 0.5 mm occurs at any point between open and closed, not just at the 90 degree position.

When the blade is closed I don't feel any movement even when I shake the handle. When the blade is locked open it is solid. I cannot wiggle the blade side to side, back and forth (up/down), or extend the blade by pulling it in or out.

It could be that the pivot holes are oversized or pivots are undersized, but I cannot figure out how to test that because I only feel the play along the arc of blade travel. If I move the blade to the 90 degree position and try to pull the blade away from the handle I cannot prevent the blade from moving along its arc of travel at the same time, so I feel the same play. I cannot isolate the two motions.

The lockbar is at a touch under 50% when the blade is locked open and the lockbar doesn't move inward with gentle pressure, so all good there. Also, the blade travels smoothly; not as smooth as my ZT 0801 but relatively close.

I like the knife a lot, though the carbon fiber is a little smoother than I expected; even smoother than my 0770CFs and the satin blade seems hard to keep clean.
 
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I have the same blade, mine is rock solid. ZT customer service is darn good. I think you may have to fill out a warranty paper. ZT will take care of you. Or reach out to the seller.

The ZT 0562cf seems to be harder to come by. I personally would sent it in to ZT and follow their instructions.
 
This doesn't seem to warrant a return to the seller or to ZT.
The knife stays closed when you want it to and is rock solid when locked open? Then there is no problem.
The 0562 is meant to be a dedicated flipper. You should never notice this "issue" in real use because there is no controlled slow opening option. It's most likely kept loose so it opens perfectly with the flipper.

I suggest you stop looking for problems, use the knife as intended, and enjoy.
 
spketch said:
You should never notice this "issue" in real use because there is no controlled slow opening option. It's most likely kept loose so it opens perfectly with the flipper.

I suggest you stop looking for problems, use the knife as intended, and enjoy.
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You're right, I shouldn't have noticed it, and I do tend to look for problems.

Thanks all for presenting opinions and options.
 
spketch said:
This doesn't seem to warrant a return to the seller or to ZT.
The knife stays closed when you want it to and is rock solid when locked open? Then there is no problem.
The 0562 is meant to be a dedicated flipper. You should never notice this "issue" in real use because there is no controlled slow opening option. It's most likely kept loose so it opens perfectly with the flipper.

I suggest you stop looking for problems, use the knife as intended, and enjoy.
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I agree. If the blade is solid when locked open, and solid when fully closed, then you have no problem. How it gets from closed to open doesn t matter. It s a flipper. It s not meant to be opened slowly.
 
I think you're fine and just happened upon a little something. A half mm isn't much. It could be it's just a break-in thing too. Once everything seats it may be gone.

If the knife works and you're happy with it in all other ways it becomes a matter of whether it will bug you for the life of the knife. If so, send it back for repair. If you can forget about it then just enjoy the knife. My guess is that will disappear over time.....
 
I don't have an 0562, but I'm pretty sure I know what you're talking about- I have a couple of other caged bearing knives that exhibit the same "looseness." I believe it's caused by the caged bearings allowing the slightest hint of rattling; however, it's definitely a non-issue performance wise. I honestly don't even consider it a fault, just a quirk of how caged bearings work.
 
salehonasi said:
I don't have an 0562, but I'm pretty sure I know what you're talking about- I have a couple of other caged bearing knives that exhibit the same "looseness." I believe it's caused by the caged bearings allowing the slightest hint of rattling; however, it's definitely a non-issue performance wise. I honestly don't even consider it a fault, just a quirk of how caged bearings work.
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This. I have had several customs on bearings that had a similar feeling. What you have to remember is that .5mm at the tip is really like .05mm of movement at the pivot point.
 
spketch said:
This doesn't seem to warrant a return to the seller or to ZT.
The knife stays closed when you want it to and is rock solid when locked open? Then there is no problem.
The 0562 is meant to be a dedicated flipper. You should never notice this "issue" in real use because there is no controlled slow opening option. It's most likely kept loose so it opens perfectly with the flipper.

I suggest you stop looking for problems, use the knife as intended, and enjoy.
Click to expand...

I agree. What is being described is normal for a knife that has the KVT bearings.
 
I have a couple of knives with washer pivots that do this as well. It's never affected performance, it's just the nature of some blades, it is a non issue. Your knife is fine.:thumbup:
 
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