Screw Tension vs. Blade Stiffness.

L

lunumbra

Joined
Jul 4, 2002
Messages
571
When I clean my Sebbie, I always end up playing the the tension on the screws for a while. If I make them to tight then the blade is very hard to open, If I leave them loose enough that the blade is easy to move, there is barely enough tension on the screw to call it "snug". I'm afraid I'm going to lose a screw.

Any Suggestions?
 
The blade bushing, stop pin, and purple ti backspacer act as standoffs to maintain uniform distance for the knife to operate when the screws are tightened all the way. You should not leave any screws loose, but rather lube it and work it open and shut to the desired tension.

Professor.
 
Sebenzas are not like other knives in which the pivot screw makes the blade smooth or hard to open based on how tight it is screwed in. These screws are designed to be tightened all the way down. The reason your sebenza becomes easier to open with the screws loose is the slabs of the frame are farther apart, thus making the locking bar exert less pressure on the blade. There is a simple fix that doesn't make the lock any less secure, but it makes it exert less pressure on the blade. This makes the blade easier to open. All you have to do is pull the locking bar the opposite direction. Do this a little at a time and test your knife. Keep doing it a little more each time until you get the results you are looking for. Your lock will still engage at the same place, and it won't be any less effective. Give it a try. It will help a lot.

Mike
 
First thing to test is tighten the screws down fully, open the blade, and use your thumb to press the lockbar out of the way. The blade should rotate very easily and smoothly, if it doesn't and you have it well lubed, sent it back to the factory for adjustment.

Otherwise, it is the lockbar friction, use a toothpick to reach in and apply a bit of lube to the detent ball. Tweaking the spring action is a last resort and I would be hesitant to do this.
 
If the knife is assembled correctly the blade should open easily. The method of reassembly that I use is as follows; assemble both side together and fully tighten the bottom two screws, next lube and assemble the blade with the washers and slide the blade assembly into the knife with the blade positioned halfway between open and closed, insert the blade piviot screw and fully tighten it, flick the blade open one time and your done. This is the only time Chris Reeve recommends flicking the blade.
 
Hey Guys...I don't think any of you have this one properly diagnosed. It sounds more like he is pinching/crimping a washer. Check this quote from Anne taken from the FAQ.

"If you have trouble putting it back together, start the procedure again. Check that the washers to do not get crimped – this is a common reason why the blade feels stiff."

By loosening the pivot, lunumbra is uncrimping the washer so the blade moves. You really have to make sure the whole thing is seated properly for that buttery smooth action.

JT
 
I say

1-DO NOT BEND ANYTHING!
2-Lube everything that moves.
3-Make sure the washers are in straight and centered on the pivot.
4-TIGHTEN screws!
5-Make SURE to lube detent ball path.
 
Originally posted by Medic1210
There is a simple fix...All you have to do is pull the locking bar the opposite direction
Click to expand...

Hmmm, you guys ought to ask Lenny if this works ;) :p :D

Matthew

P.S. Hey Lenny, sorry to bring that up again! :)
 
I agree with JTurner, he is pinching the washer. The tolerances are very tight and this is one area that requires extra care with assembly.

I have the frames assembled with slight clearance (loose frame screws) blade, bearing sleeve and two washers all assembled and held in place with CRK grease. With finger pressure squeeze the frames together and slide the blade/washers into the frame while holding the locking bar open with thumb. This is my method of keeping the washers from moving out of position. Now insert the back side threaded sleeve and lastly the pivot screw.

Regards,
FK
 
But......DON'T BEND THE LOCK BAR!!!!!!!!!!!!!!

Disassemble the knife and start over. Make sure everything is lined up. At first tighten the screws down with the blade open and lockbar engaged. You may find the blade hard to close. Loosen the screw a little, still with the blade open, then close the knife. Retighten the screws securely. This should work.:)
 
I had exactly the same problem. I discovered that a washer was not properly aligned. Sorted it out and my Sebenza is now silky-smooth in operation.
 
Originally posted by K-guy
But......DON'T BEND THE LOCK BAR!!!!!!!!!!!!!!

Disassemble the knife and start over. Make sure everything is lined up. At first tighten the screws down with the blade open and lockbar engaged. You may find the blade hard to close. Loosen the screw a little, still with the blade open, then close the knife. Retighten the screws securely. This should work.:)
Click to expand...

So what is the big deal about bending the lock bar a bit? You still get great lockup, and if you would like the blade stiffer to open, you can bend it the opposite way. It isn't like a liner lock in that being looser might cause a faulty lockup. The inherent design of the frame lock is one that your grip makes the lock even more secure.

What if he does all your steps, and still has a stiff blade as I am about willing to bet will happen? From what I've seen with a very stiff Sebenza is if you hold the lock open with your thumb, the blade moves along the pivot very easily, which means that the washer isn't misaligned but instead, the lock bar is just exerting excess pressure on the blade. Sure, the general consensus is to "work it out with lube and frequent opening and closing", but I'm just giving another alternative. If you aren't comfortable with a slight adjustment of your lock bar, then don't do it. It's as simple as that. No big deal. But there are some people out there who aren't afraid to go against the grain to get the same result a little quicker. Like I said, it can always be adjusted back to it's original tension.

Mike
 
Originally posted by Starfish
Hmmm, you guys ought to ask Lenny if this works ;) :p :D

Matthew

P.S. Hey Lenny, sorry to bring that up again! :)
Click to expand...

Could you please fill those of us who are less informed in as to who Lenny is, and what situation you are referring to, just in case he doesn't respond.

Thanks,

Mike
 
Originally posted by Medic1210
Could you please fill those of us who are less informed in as to who Lenny is, and what situation you are referring to, just in case he doesn't respond.

Thanks,

Mike
Click to expand...

Sorry, it's a somewhat old thread, and a long one as well. This is the standard response we have whenever someone suggests messing with the lock bar.

The Lenny Thread

By the way, there are several reasons why people get vocal about modifications to the lock bar. Voiding of the warranty is the big one, and it would be kind of unfair to a FNG if he ended up with a less-than-optimal Sebbie because he followed someone's advice without realizing that the adjustment could possibly turn out to be a warranty-breaker.

Hope that helps,

Matthew
 
Matthew,

Thanks for pointing me to that thread, I just finished reading "every part" of it. I highlight "every part" because it seems that quite a bit of it is missing. I noticed when I first started that it kind of jumped in with both feet without giving any history of the situation. The posts are out of order for the most part (however the time/date sequence suggests otherwise). It wasn't until about 11 or so posts down that I saw Lenny's original case presented. If you read the link, you will see what I mean. Also, I'm sure there was more left out, but people mentioned that Lenny was happy with his new knife. I saw this nowhere. Also, the lockbar bendind issue was mentioned at the very end as a bit of reference to someone else. Nothing else was mentioned about it or what Lenny actually did. Through the entire thread (that which is still there) I took it that the lockbar wore out too much. I remember seeing a comment from Anne somewhere that the lockbar was initially hardened to a Rc less than the blade Rc. Thus this led to premature wear of the lockbar. This is why they specially heat treat, and I believe coat with Ti Oxide the tip of the lockbar to a higher Rc. For this, I was thinking the whole time that CR should have replaced the knife free of charge. Unfortunately, the important stuff that you wanted me to see regarding the lockbar bending issue has apparently been "lost." I guess this could be considered a "modification" of sort, but I just looked at it as decreasing tension. I really wish the entire thread was still available to read, because I feel some important info was missing. Also, as far as your FNG reference, "Voiding of the warranty is the big one, and it would be kind of unfair to a FNG if he ended up with a less-than-optimal Sebbie because he followed someone's advice..." What is an FNG. I did see only one post near the very end of your link made by somebody named FNG who has been banned. What was he banned for, and was he what you were referring to? Just wanting to learn. Thanks.

Mike
 
lunumbra's orignal post said he got this problem after cleaning the knife. I can understand if maybe when he got the knife new and had a problem with blade stiffness, maybe monkeying with the lock bar would work. But as stated, he's having the problem putting it back together. The assembly I mentioned is the way I do it and it works. I've experienced the same problem in the past and aligning the washers again and setting the screws in fashion I mentioned previously works.

Didn't mean to step on your toes Medic. We all have our own soultions to quick fixes. I've for one have taken other liner locking knives and done your prescribed method with great results!;)
 
Thank you Folks!
Took it apart again and took a good look at the washers. turns out the I had pinched the large washer. (I was expecting trouble with the small one...just goes to show ya!) In fact I pinched it hard enough to imprint the curve of the pin in the washer. I got out my super fine ceramic stone and polished both sides of the washer, put it back together (carefully!) with oil between every layer and voila! It's Beautiful!

I feel sooo much better......aaaaahhhhh
 
Originally posted by K-guy
lunumbra's orignal post said he got this problem after cleaning the knife. I can understand if maybe when he got the knife new and had a problem with blade stiffness, maybe monkeying with the lock bar would work. But as stated, he's having the problem putting it back together. The assembly I mentioned is the way I do it and it works. I've experienced the same problem in the past and aligning the washers again and setting the screws in fashion I mentioned previously works.
Click to expand...

I took it that he always has to leave the screws loose in order to have a smoothe blade. The reason being is, I have handled a couple Sebenzas now, and both are very tight. In fact, I don't see how someone could flick it if they wanted to (I have stated that I can flick any one handed knife in the past, but now I can't say that). One of the Sebenzas is not new, but never disassembled, and it is still tight. If it is an assembly problem, then if he holds the lock bar open with his thumb (as if to close it), the blade should still be stiff right? If he tightens all screws down like CRK designed it to be done, the blade should be loose with the lock bar held open, right? Maybe Lunumbra could clarify for us which situation he is experiencing.

Didn't mean to step on your toes Medic. We all have our own soultions to quick fixes. I've for one have taken other liner locking knives and done your prescribed method with great results!;)
Click to expand...

My toes are just fine:D. No offense taken. I was just wondering what everyone's aversion to the lock bar tension fix was about. I think the above link might have explained it some, but unfortunately that link is apparently missing a lot of posts.

Still wondering about the FNG reference from Starfish.;)

Mike

Edited to add: I see Lunumbra cleared up my question as I was typing this long-winded response. Good to know.
 
Hi Mike,

Yeah, I noticed that too after I read it a bit. If you noticed, there were a couple of links inside that thread that referenced the problem in greater detail. Unfortunately, those links do not appear to work anymore.

Someone who was more involved than I should probably clarify the situation, but here is how I understood it: Lenny had a problem with the lockup, CRK refused to treat it as a warranty due to perceived "flicking", then it turned out that the problem originated with Lenny's modifications to the lock bar.

This was a big deal at the time, since it called into question CRK's warranty, with people on one side of the flicking debate and people on the other side. Once it was determined that the lock bar had been modified, it became a no-brainer.

I don't know if your modification is the same as Lenny's, but I tend to want to err on the side of safety when it comes to voiding the warranty of a high-end knife like the Sebenza. I also highly value CRK's customer service. If I felt like the opening action wasn't as good as it could be, I would send it in to the shop with a detailed note so that they could look at it themselves. The CRK shop bends over backward to ensure the end user's satisfaction - I know this from first-hand experience...several times!

FNG: F-ing New Guy :) Probably a poor attempt at humor; I don't think of anybody that way - we were all new once!

Sorry for the confusion,

Matthew
 
Let's see if I can summarize:

Lenny bent the lock bar himself trying to "fix" it. That caused problem in how the lock fit and hence prompted CRK to think there was an abuse problem.

FNG means F******* New Guy

This was what I was referring to in the passaround sebbie thread.
 
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