Sebenza 31 open/close "blade play"

C

CO_EDC

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Oct 9, 2012
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I just got my first CRK. A used Sebenza 31 PJ. When I first got it it had a bent washer so I sent it back to CRK for the spa treatment. Just got it back and there's a little bit of "blade play" for lack of a better term when opening and closing the blade.

Basically, with the blade part of the way open if I hold the tip and move the blade back and fourth in the open/close directions there's a bit of play before you feel the "smooth" action.

Is this normal? None of my other knives have this feeling. I know it's nitpicky but for what these cost (and how they are touted for their hydraulic action) I wasn't expecting any play.

Thanks!
 
Call CRK and let them know. Some really minuscule play is possible. If it was not you would not be able to push the pivot screw through the bushing.
 
I'll give them a call. It's hard to describe but it's rotational play before you get into the smooth action CRKs are known for. I can open/close the blade a bit with no resistance before the blade starts to move like normal
 
SuzukiGS750EZ said:
You mean like the detention ball has too much play in the detention hole in the blade?
Click to expand...
No, once the blade is open part way. But it kind of feels like that. My para 3 lightweight had detent play when it was closed and it's a similar feeling. I'll try and take a video tomorrow to show it.
 
This is something I’ve felt on every sebenza. Assuming the feeling is from the blade and non tolerance fit bushing taking up the slack and moving slightly. Would explain why it only happens when you reverse the direction. This is not something i would consider blade play.
 
Have you tried holding the lock bar away from the blade when this happens to see if it goes away? Or give the knife a generous amount of grease?
 
Kallil said:
This is something I’ve felt on every sebenza. Assuming the feeling is from the blade and non tolerance fit bushing taking up the slack and moving slightly. Would explain why it only happens when you reverse the direction. This is not something i would consider blade play.
Click to expand...

This.

The play OP feels is just the from the pivot and is the necessary play needed for the blade to be able to open/close.

This is a "problem" that comes up on the forums every now and then. Maybe there should be a sticky post explaing it in this subforum?
 
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This up/down play in a half-open state is normal and is present on all CRKs. There must be some space between the pivot bushing or pivot screw and the blade steel, or the knife would seize solid as it heated up or cooled down, and there would be no room for lube. This small amount of intentional play is exaggerated by the geometry of blade to seem like more than it is.
 
Awesome, thanks for the replys! I hadn't felt it in any of my other knives so figured I'd ask. I did break it down before posting and cleaned it and added some grease which helped but it didn't completely go away. If it bugs me maybe I'll just try a little more grease to take up the play.
 
Decided to take it apart, clean it and add some more grease and that got rid of any movement I was feeling. Thanks!
 
Glad to see that you found your solution! 👍
Do you think that a "thicker" grease might also have worked?
(Wihout the second helping of it...)
 
Bob Denman said:
Glad to see that you found your solution! 👍
Do you think that a "thicker" grease might also have worked?
(Wihout the second helping of it...)
Click to expand...
I think a thicker grease would have worked too. I'm still not sure if the play is between:

Blade and washers
Washers and handle (unlikely)
Blade and pivot bushing
Or pivot bushing and pivot screw
 
Did the washers show an unusual amount of wear?
Can you get a measurement of their thickness? If you can: I'd call CRK with that measurement, and see what they have to say.
Good luck! 👍
 
Bob Denman said:
Did the washers show an unusual amount of wear?
Can you get a measurement of their thickness? If you can: I'd call CRK with that measurement, and see what they have to say.
Good luck! 👍
Click to expand...

The new washers didn't show unusual wear.

For sure. I can measure the washers and make sure the washers plus the blade thickness equals the pivot bushing thickness. But in my mind if the washers were too thin that would cause blade play in the "normal" direction:

https://imgur.com/a/8u54z0N

What I'm experiencing is a bit of play in the open/close direction when the knife is part of the way opened:

https://imgur.com/a/zohcV6H
 
Oh: you're getting some "blade rock"? (What I guess I call it...)
If it locks up tight, and there is no lateral blade movement: I think your grease solution is a winner.
 
Correct. I measured bushing and recorded number. Measured each washer and blade and recorded that number. Then took the bushing down to size. That doesn’t sound like the case here, but measured anyways for S&G.
 
Bob Denman said:
Oh: you're getting some "blade rock"? (What I guess I call it...)
If it locks up tight, and there is no lateral blade movement: I think your grease solution is a winner.
Click to expand...
That's a better term for it! I didn't know what to call it. Blade locks up solid. And once it's moving it's smooth.
 
353 said:
This.

The play OP feels is just the from the pivot and is the necessary play needed for the blade to be able to open/close.

This is a "problem" that comes up on the forums every now and then. Maybe there should be a sticky post explaing it in this subforum?
Click to expand...

kidcongo said:
This up/down play in a half-open state is normal and is present on all CRKs. There must be some space between the pivot bushing or pivot screw and the blade steel, or the knife would seize solid as it heated up or cooled down, and there would be no room for lube. This small amount of intentional play is exaggerated by the geometry of blade to seem like more than it is.
Click to expand...

^ This. I know you just dropped some good money on a Sebenza, but these two longtime members have it right. It is totally normal, no need to call CRK (of course I am sure they would be more than happy to explain to you); those that have actually owned Sebenzas for some time will tell you it is just fine. However as 353 said it is a commonly asked question, so I am not trying to hack on you at all. The CRK grease when applied (while still fresh) can seem to eliminate the “issue”, but that is likely only to be temporary until it wears in.
 
BTTLBRN said:
^ This. I know you just dropped some good money on a Sebenza, but these two longtime members have it right. It is totally normal, no need to call CRK (of course I am sure they would be more than happy to explain to you); those that have actually owned Sebenzas for some time will tell you it is just fine. However as 353 said it is a commonly asked question, so I am not trying to hack on you at all. The CRK grease when applied (while still fresh) can seem to eliminate the “issue”, but that is likely only to be temporary until it wears in.
Click to expand...
I appreciate all the replies! I figured it wasn't anything to worry about but none of my other knives had that so I figured I'd ask. I tried to Google it first (and search though this forum) but I didn't know what to call it and if you look for "blade play" you just get threads for typically side to side blade play or the lock rock issue (which luckily mine doesn't seem too have).

Loving the knife so far! I sold off a few knives to fund it and am thinking about starting that "1 knife for a year" challenge Glock Guy started.
 
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