Why no bushing pivot on Umnuumzaan?

kgajewsky said:
I'm having the same issue with an Umnumzann that I got in the mail today. Used. But I noticed when I loosened one of the pivots the blade would not center. If I tighten it down, I can't open it. I'll pull it apart tonight and clean and lube to see if that will help. It's a Wilson Combat version from 2012. Very nice looking but need it to be more smooth. In addition to the difficulty opening it isn't super smooth opening. A bit "rough" if you know what I mean.
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Extra lube definitely helped the situation with smoothness. But in terms of centering, I am unable to tighten it down to the point the blade is centered and I am still be able to open it. I experimented with the pivot screw and got it to the right point where it wasn't too far off from centered but was acceptable in terms of opening ease. But I had forgot to put any loctite on it..arghhh. Had to do it all over with the loctite. If you don't use it, the screw will back out enough to really throw the centering off after a short amount of time, at least with my model. Then blade play starts to be an issue if it goes too far off center.

At first I thought I had an issue with the washers being pinched. But they are flat--at least as far as I can tell. Everything fits together fine and no perceptible gaps anywhere. Maybe the washer are too thick/thin. I have no idea. Based on my searches online, enough people have brought this up though that it just isn't me. It seems to be hit or miss.

Which brings me back to the question I posed in the beginning before I went off on a tangent and complained. Why not just use the proven bushing ? I really don't understand why they didn't. This really is a nice knife outside of these issues. The blade design is awesome. I would like it better than my 21 if not for the issues.
 
BubbaGump said:
Extra lube definitely helped the situation with smoothness. But in terms of centering, I am unable to tighten it down to the point the blade is centered and I am still be able to open it. I experimented with the pivot screw and got it to the right point where it wasn't too far off from centered but was acceptable in terms of opening ease. But I had forgot to put any loctite on it..arghhh. Had to do it all over with the loctite. If you don't use it, the screw will back out enough to really throw the centering off after a short amount of time, at least with my model. Then blade play starts to be an issue if it goes too far off center.

At first I thought I had an issue with the washers being pinched. But they are flat--at least as far as I can tell. Everything fits together fine and no perceptible gaps anywhere. Maybe the washer are too thick/thin. I have no idea. Based on my searches online, enough people have brought this up though that it just isn't me. It seems to be hit or miss.

Which brings me back to the question I posed in the beginning before I went off on a tangent and complained. Why not just use the proven bushing ? I really don't understand why they didn't. This really is a nice knife outside of these issues. The blade design is awesome. I would like it better than my 21 if not for the issues.
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Did you buy this new? If so, did you try to back the pivot off ever so slightly?

Generally, the Umnumzaan opens differently than a 21, so if you are trying the same technique, you are going to have some very sore thumbs and likely will until it breaks in. The washers wear to mating surfaces after use.
 
bhyde said:
Did you buy this new? If so, did you try to back the pivot off ever so slightly?

Generally, the Umnumzaan opens differently than a 21, so if you are trying the same technique, you are going to have some very sore thumbs and likely will until it breaks in. The washers wear to mating surfaces after use.
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Yes. It is new. I am using the right technique. With the blade centered the knife won't open. Wont even budge even trying two hands. Have to back out the pivot about 1/2 turn to get it to open without excessive force. But the blade is then off to the right and no longer centered. I am contacting gp knives to see if it's possible to return it for refund or credit. I have disassembled it to lube and won't lie to them about this so don't know if it will happen. But I woild rather return than send it to cr if possible. if they decline I will weigh option and perhaps send it in or try to sell it. The reason I was sold on the sebenza was the hassle free design. This is too much hassle and never had a knife behave like this.
 
So, took it to the work bench and took the Umnumzaan apart. First thing I noticed is there there was no lube on it. Dry as a bone. Not really dirty, but I took it all down and cleaned everything really well. Washers, blade, slabs, inside the slab holes and so forth. Then back together again with a decent amount of the CRK grease. On the slab, then on the washer. On the pivot then a touch inside the pivot hole on the blade. Other washer, slab and you get the idea. Snug up the back standoff screw first then snug up the pivot screw. Now the fine tuning. Just the tinniest amount of turn on the pivot screw would be just a bit too tight. Back it off a hair and it opens more easily. I just played with it a bit. Once I felt I had the hang of it I backed out the pivot screw and put just a small amount of the red thread lock on the threads up by the head of the screw. It sucked into the threads. Back on the knife and then got it just right by tightening it then backing off just a hair. Seems to center well and opens well. The blade won't fall freely when the lock bar is pushed open, but it is very smooth now with some lube on it. None of the "roughness" from before the cleaning. Smooth. I'm gonna carry a few days and just keep working it. Love the WC Starburst pattern.
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kgajewsky said:
So, took it to the work bench and took the Umnumzaan apart. First thing I noticed is there there was no lube on it. Dry as a bone. Not really dirty, but I took it all down and cleaned everything really well. Washers, blade, slabs, inside the slab holes and so forth. Then back together again with a decent amount of the CRK grease. On the slab, then on the washer. On the pivot then a touch inside the pivot hole on the blade. Other washer, slab and you get the idea. Snug up the back standoff screw first then snug up the pivot screw. Now the fine tuning. Just the tinniest amount of turn on the pivot screw would be just a bit too tight. Back it off a hair and it opens more easily. I just played with it a bit. Once I felt I had the hang of it I backed out the pivot screw and put just a small amount of the red thread lock on the threads up by the head of the screw. It sucked into the threads. Back on the knife and then got it just right by tightening it then backing off just a hair. Seems to center well and opens well. The blade won't fall freely when the lock bar is pushed open, but it is very smooth now with some lube on it. None of the "roughness" from before the cleaning. Smooth. I'm gonna carry a few days and just keep working it. Love the WC Starburst pattern.
View attachment 612062
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I just noticed that you mentioned you used red thread locker. I thought the red stuff is for maximum strength and for permanent locking. If you don't plan taking apart the knife again, that would be ok. But if you do, you should probably use either blue or purple thread locker instead.


Miso
 
BubbaGump said:
Thanks for the replies. I ask as I just purchased a Umnuumzaan. After receiving it last week, I had mixed feelings. It was so tight I could barely get the blade to open. After researching here and online, I disassembled, cleaned, lubed, checked for pinched washers, etc. It helped and it is breaking in now. But I am finding there are trade-offs between blade play and centering. I am finding that to keep the blade perfectly centered, it is just too tight. Off center a bit, the action is fine and smooth. But when tightened so the blade is perfectly centered, I just about need a prybar to get it open.

I really like the ergonomics, look, and blade profile. But IMO, the overall design seems thrown together rather than 'engineered' like the traditional 21.

It lacks the precision and engineering of the 21. My $25 Spyderco Byrd models have the same pivot design and can be tightened down to perfectly centered without having to use a prybar to open it. They also don't require loctite to keep the screws from backing out. IMO, this finicky setup is not worthy of a $440 knife. I don't think I could say they dropped the ball but they definitely cut corners. I know this might ruffle some feathers but I think it is definitely the name that is selling this knife at the $440 price point. For what I got and the tolerances and finicky nature of the pivot, it is overpriced, by about $200. I don't see how they can use tolerances and engineering to justify the cost on an adjustable pivot requiring loctite to keep everything from quickly going out of whack.
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You might just have gotten the 1 in 10,000 dud from CRK.
 
After reading through this thread, I feel compelled to post a couple excerpts from Chris in his "Some words from Chris" sticky thread. Chris' words speak for themselves:

"I*am not*super-human; I make mistakes, mis-quotes and mis-judgments right along with the next person. I*am*passionate about my knives and my company. I have been involved in manufacturing for 38 years. I apprenticed as a Tool and Die maker and worked in that trade for 13 years before becoming a full time knife maker. I made my first knife in 1975. I tell you all of this to endorse the fact that the majority of my life has been spent in studying and working with steels, knives and cutting edges. That I have the ability to design knives is a bonus, and is an area at which I have worked hard. I believe in simple mechanisms designed to function optimally, with the closest attention to engineering detail and with the best available materials. In the 26 years of Chris Reeve Knives, these characteristics have been the foundation of this small company that we humbly recognize as a leader in the knife industry."

"If you have a problem with our product, whether perceived or real, please contact us first. We always respond as soon as we can to email and telephone calls. The progression of a post on a perceived problem usually sets in motion all kinds of extrapolation, criticism and negative comment that benefits no one, least of all us. This is a public forum – what is posted here can be read by absolutely anyone, so think about what you say."
 
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miso2 said:
I just noticed that you mentioned you used red thread locker. I thought the red stuff is for maximum strength and for permanent locking. If you don't plan taking apart the knife again, that would be ok. But if you do, you should probably use either blue or purple thread locker instead.


Miso
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I used the thread locker that came in the box with the Umnumzaan. It is reddish in color. I'm figuring the stuff that came with it is supposed to be what I use... Anyone??
 
The CRK supplied thread lock is Purple. Purple is low strength, blue is medium, red is high strength. I could be that you thought it looked red. The purple is #222, the blue is #243, and the red is #263.
 
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