Umnumzaan lockup and tool

Sharpski

Sharpski

Joined
Jun 10, 2012
Messages
784
Disclaimer, I love CRK !!

I have had umnumzaan for about 4 months or so and I love the knife. I own lots of CRK knives and this one finds a lot of pocket time. I have a few concerns that I was hoping to find a solution to.

First the lock up is late...real late, like 80%. No blade play what so ever, but this worries me a little as I bought it the month it was born (march). Should I be concerned? I only want to send it back to CRK if it is totally necessary as it takes time and money and I didn't really expect this from CRK. (Remember I love all my CRK's and I am obsessed with their quality!!)

Also, I have some issues with the tool. Normally CRK products consider every detail and have some of the highest quality and blah blah blah, I am preaching to the choir here, but I feel like the tool was designed by a 4th grader.. haha.

Jokes aside I have snapped off all of the pins on one of the tools. Now what? Pay another 15$ for the same thing to happen? I get why they are plastic (will not scratch) but I would like the tool to work for more than two weeks. I also have an issue with the allen wrench they give you for torque bars? The short end will scatches the finish on the Ti as you rotate unless you hold them just right and they are loose in the hole of the tool.

With the high tolerance and attention to detail that made CRK famous (and made me fall in LOVE with them) I would have expected straight rods that fit in the holes of the tool like a pivot busing fits in the blade of a sebenza. I thought about machining some, but like I said I busted the pins so its worthless at this point.

Has anyone else run into this problem? Any solutions?
 
I have a delrin tool set with my 2008 Umnumzaan that is still pristine. Did you perhaps not keep them flush to the tool when they spun?

No, there is nothing wrong with your lock up. A search on the topic will show without a doubt that late-looking lockup is the norm straight from the factory.
 
kreole said:
I have a delrin tool set with my 2008 Umnumzaan that is still pristine. Did you perhaps not keep them flush to the tool when they spun?

No, there is nothing wrong with your lock up. A search on the topic will show without a doubt that late-looking lockup is the norm straight from the factory.
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Yea I have owned enough CRKs to know the lock up is later out of the factory and that they carborize the lock face which helps. I guess I have never had any that was this far over. I guess the line is closer to 95%.

About the tool, no I kept them flush but that could do it.... There may have been a little more loctite than was needed but I am pretty sure I lost one of the pegs taking it down for the first time..Maybe I just had a dud.
 
The lock on the Umnumzaan has a ceramic ball that contacts the blade tang, not a carborized titanium lock face. The lockup is late because the knife if designed that way.
 
I was talking about the sebenza 21 not the about the umnumzaan. This is the first zaan and was referring to my 21s. I will be more specific next time, sorry about that confusion.
 
Sharpski said:
I have had umnumzaan...

First the lock up is late...real late, like 80%.
Click to expand...

I was referring to this, the ceramic ball makes for a later lockup than a titanium lock face.

Sorry if I misunderstood your post(s).
 
The ceramic ball set up on the Umnumzaan makes for what looks like later lock up. If you check where the marks on the blade tang are you will see that they tend to sit at ~60%. I have 4 Umnumzaans and they all lock up the same.

The tools that CRK provide are just fine as far as I can see, I have no idea how you were able to snap the pins off with out doing something out of the ordinary. Are both tools shot or just one ? You only actually need one tool if you take it easy on the loc-tite. That said I do carry a hand made Titanium tool that is pretty much unbreakable. :):thumbup:
 
To add to Haze's point about lockup, unlike the titanium/steel wear interface on the Sebenza, the ceramic/steel wear interface on the Umnu won't. Wear, that is - not going to change. ;)

I have not had any trouble with the takedown tool, fwiw. Maybe pure 1/1MM bad luck. :(

Haze said:
The ceramic ball set up on the Umnumzaan makes for what looks like later lock up. If you check where the marks on the blade tang are you will see that they tend to sit at ~60%. I have 4 Umnumzaans and they all lock up the same.

The tools that CRK provide are just fine as far as I can see, I have no idea how you were able to snap the pins off with out doing something out of the ordinary. Are both tools shot or just one ? You only actually need one tool if you take it easy on the loc-tite. That said I do carry a hand made Titanium tool that is pretty much unbreakable. :):thumbup:
Click to expand...
 
Oh i will have to check next time I take it apart. Thats good to know thanks!

Interestingly only one of the tools had pegs that snapped off (all four now). Its very weird as i really don't think i was man-handling it. It was seriously the first time I used it and I was still in the its so beautiful I don't want to touch it or I will mess it up phase ha! I may just call the place I got it (a major dealer) and see if they can throw me a bone and replace it..
 
Sharpski said:
Yea I have owned enough CRKs to know the lock up is later out of the factory and that they carborize the lock face which helps. I guess I have never had any that was this far over. I guess the line is closer to 95%.

About the tool, no I kept them flush but that could do it.... There may have been a little more loctite than was needed but I am pretty sure I lost one of the pegs taking it down for the first time..Maybe I just had a dud.
Click to expand...

CRK doesn't carborize, carbidize, or carburize any of their knives :)

Hmm I wonder if you did get a dud then. I was worried about it happening when I first got it because they are pretty small protrusions--not much meat there comprising each peg--but no problems fortunately. Anyway, there are posts about taking apart the Um without the tool. I seem to remember someone used thin screwdrivers (two per side), and someone else recommended toothpicks. I'd probably try the toothpicks.
 
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I can't recommend any thing specific to the taking down of the umnumzaan as I have never taken my down; but as an industrial mechanic I have seen many a friend smack a knuckle or hurt a piece of equipment when taking down anything with red loctite on it. The answer is always heat to loosen it. We usually hit it with a torch and replace the bolts, but I am betting a heat gun or dipping it in boiling water for a few minutes should sufficiently loosen it up to not snap the tools. Plus the boiling water should not be hot enough to change any of the metallurgical properties.

Best of luck!
 
CRK actually use purple low strength loc-tite. It's very easy to break the lock if you use it sparingly. You literally just need a spot on the thread of the male pivot screw. I can break the lock with only one tool by opening the knife to brace the pivot and only thumb pressure to help things along.

If you go to a good heard wear store you can pick up an adjustable pin wrench, (it may be called something different in the US ?) That will last for ever and work on watch cases, flashlight heads and Umnumzaan pivots a like. :):thumbup:
 
Haze said:
CRK actually use purple low strength loc-tite. It's very easy to break the lock if you use it sparingly. You literally just need a spot on the thread of the male pivot screw. I can break the lock with only one tool by opening the knife to brace the pivot and only thumb pressure to help things along.

If you go to a good heard wear store you can pick up an adjustable pin wrench, (it may be called something different in the US ?) That will last for ever and work on watch cases, flashlight heads and Umnumzaan pivots a like. :):thumbup:
Click to expand...

Yea I didn't use that much, so I don't really think that was the issue. Plus one pin snapped off the first time I took it down and it was brand new so it had the factory amount of loctite.

I actually have one of those I will have to see if I have pins small enough to fit into the zaan's pivot. I am in the process of trying to getting one of those Ti custom-made tools, so thats probably my best option for now. ...At least I confirmed my suspicion. Thanks guys!
 
on mine the ball made a round mark in the middle of the blade's tang, which IMO is the right spot
lockup is like in yours but has to be viewed differently from the rest of the knife world, different system
 
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