Gunting lock warning

Howard Wallace

Howard Wallace

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Feb 23, 1999
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I have one of the early Guntings. I am enamoured of this knife and use it as my daily carry and utility blade. As a utility blade it is often called into service to cut apples or other foodstuff. It is carried in my pocket in a custom Skunkworks pocket sheath so it is regularly exposed to pocket lint.

As I was idly playing with the knife this evening I found that I could unlock the blade with just light thumb pressure on the back of the ramp. I locked and disengaged the knife this way at least 10 times.

I got out my drone to compare the two and locate the problem. The liner on the back of the drone travels over halfway through the open space when I lock the drone. The liner on my carry knife was traveling only a small fraction of this distance and barely engaging the locking mechanism. I am sure that the knife was not doing this when I first purchased it and put it through it’s paces.

I got a thin screwdriver and pried on the liner. Now it travels about 1/3 of the way through the open space and engages the locking mechanism solidly. Perhaps the liner was glued in place by gunk, or perhaps the spring is fatiguing.

I don’t intend to return the knife unless this problem becomes worse. I like it too much. But I am going to be aware of this failure mode and check the lock before I go stabbing any tires. Other Gunting owners may wish to periodically check the travel of their liners also.
 
That's interesting. With my index finger I prevented the liner from fully engaging the lock on both Guntings I have and tried with my left hand to fold the lock. No good. I then just barely let the liner engage (not even its full width) and it still prevented the blade from folding.

Now I am pretty sure if the liner was only partly on the cutout and I went down hard at full force with a wrist torque I could fault the liner as it probably would fracture at the face, but the force it would require is significant.

-Cliff

[This message has been edited by Cliff Stamp (edited 04-19-2001).]
 
Tried the same thing as Cliff and had the same results. Even with the lock barely engaged it held up.

I would suggest a severe cleaning, oiling, and make sure that the pivot is at the right tension. If that doesn't fix the problem, send it in!
 
The knife is functioning properly since I pried up the liner. I agree that the lock holds with even a small engagement of the liner. When the lock was malfunctioning the engagement was minimal and this allowed the knife to unlock with only a small amount of pressure. I estimate the force that caused the knife to close at 2 to 3 lbs., exerted by my thumb on the ramp.

I think the most probable explanation is sticky stuff getting in the knife and gluing the liner down. Of course, this is no one's fault but my own.

Nonetheless, I thought others might be interested in my experience.
 
Hi Howard. Sorry you are having a problem.

Though you would prefer not to "give up" your knife for a while, It would probably be better for us and for future Gunting owners if we could get to look at it.

This is a new lock concept and the Gunting was the first knife to "test" it. We are still learning about the lock. If the lock is doing something that could perhaps be unsafe, it is important that we can investigate a "real world" example.

You could contact Mike at Spyderco Warrantee & Repair (800-525-7770), let him know this discussion and tell him that it would be great to get it back quickly. Please ask him to call the piece to my attention.

If you would be so kind, we can get a problem free knife back into your hands quickly...and learn something.

sal
 
Sal,

I sent it to the e-mail in your profile (sglesser@spyderco.com) before I posted the last note. Is that address still good?

I'll resend the note this evening when I get back to my home computer.
 
The first time I posted about this there was some healthy skeptisism. I had already cleaned up the knife so it was functioning properly and could not take data on actual values. I tried a couple of times to e-mail Sal re sending the knife for exam but I never managed to get through. Then life got busy and I dropped it.

The problem came up again after pulling the knife out of long-term storage. No problems, as I checked the knife for problems and caught it. But I did take some measurements.

This problem may have already been ID'd and solved, in which case this post is of little value. For what it's worth, here is the data for Gunting #504 in its failure mode. I did take some pictures but now my computer is telling me the disk the pictures are on is not formatted. I had this problem before and know I can solve it by having my friend's camera read the pictures and then e-mail them to me. That process takes a couple of days though.

Travel of liner at end where it engages blade is approximately 1 mm. This is considerably smaller than it should be for proper engagement.

To measure the torque causing failure when the liner is minimally engaged like this I cut a large hole in the top of a plastic milk jug. I then suspended the jug by a string from the hole in the blade. I placed the opened knife sharp part of blade downward on the edge of a table with the blade hanging over the edge. I held the back end of the knife down with hand pressure at the solid spacer near the back. I held at this position so as not to interfere with the movement of the liner. Then I slowly poured water into the milk carton. At 6 1/2 cups of water the lock failed. Since "a pint's a pound the world around" this represents a force of 3 1/4 lbs. The horizontal distance from the pivot to the opening hole is approximately 1 inch, so the torque at which the lock failed was 3.25 in-lbs. This is enough to present the illusion of lock engagement when in fact there is no effective lockup.
 
That is so wierd. I'd send it in, or..
with the knife closed, take a toothpick and clean out the blade (where the liner makes contact with the blade) then, take rubbing alcohol on a swab, and clean the same area. then, try changing the tension of the pivot pin. It's happened to me once, and that's due to dirt/spooge. Good luck, Joe
 
Howard:
I've sorry anything like this happened to you....
Nor have I EVER had a lock failure..And I abuse the lock..I yank students around by it...I do "breaks" against the lock...I hammer with it open...
So I'd send yours in..
Gotta have one lemon in the group..Seems you found it way back in 01...you should have sent it in..
SEND IT BACK....
Tell them Bram said so...and so did Sal..
Get a new generation with your number put back on it...
They just came out from final re engineering....
The locking lever, the anvil pin and the center pivot pin have evolved over time...
Obviously from your description it wasn't correct to start with...
And Sal way back then said to send it in..
Do it..
It obviously isn;t right..
Don't fix it..don't play with it..get one that is correct..

be safe
Bram
 
Bram,

Thank you for your kind concern.

I fear some things were not clear from my previous communications. Permit me to explain.

1. I am not complaining. Nothing bad has happened to me so there is no reason for anyone to be sorry.
2. I have no intention of sending this knife back unless I can get assurance that proposed modifications or replacements will not be made without my consent. I believe any tool has limitations, and if I understand those limitations I work within them. This tool with its limitations functions for me. If it were to come back to me with, say, a serrated blade it would be much less useful to me, no matter how reliable the lock. I would also like to retain the same blade for sentimental reasons, although I might consider replacement of the blade if absolutely necessary to accommodate design changes in the new model. My previous attempts to communicate via e-mail were unsuccessful and I gave up on them. My e-mail does work though should anyone wish to contact me.
3. I know how to minimize this issue by the cleaning and prying up the liner as noted in my first post, and as suggested by ThinkOfTheChildren and Dijos (who by the way noted a similar occurrence). I purposefully didn’t fix the problem this time because I had previously made a mental note to take some hard data to convince Cliff that blade fracturing force was not necessary to produce the effect I described.

I suspect that the lockup problem may not an issue with the current production, as you say that there have been some design changes in the critical elements.

Take care.

Yours respectfully, (but not obediently, I’m funny that way)
 
Howard:
Hey..I know you're not complaining....though you have th right to...
you have an extremely early model..Many corrections in the building-assembly were made. It was a learning process and the Gunting is hand assembled in Golden..NO machines for us,,and yes its definately touched by human hands..
Over time since then early problems or non continuity of assembly have long since been corrected..
There were slight engineering and production enhancements..
WHY?? Because its a slam n jam, balls to the wall user knife..It's a hard use tool with no limitations..It rocks and rolls with the best of them...
Its not used to cut paper and rope..or open boxes..
it can..but its not..
it goes to real deal get the bad guy type users...
and its taken out the BG's, arrested BG's and saved lives...

Ok I understand sentimentality..keep the freaking old one and get a new one..yes its partially serrated..but its freaking cool..and its sharp!..
And the lock is a tank!...

be safe
Bram
 
Bram,

Your design has a touch of genius and I suspect I am going to end up with one of your new models before long.

To complete the documentation here are the pictures I could not post before.

1. knife
 

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