Umnam assembly problem

ridnovir

ridnovir

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Mar 12, 2012
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1,473
So, I took apart my new Zaan (new pivot) (for the first time) and when I reassembled the blade is skewed to the right (face scale) if I tighten the pivot it goes somewhat to center but I cannot open the knife then. I am pretty sure I did everything right (female side of pivot liner lock scale washer blade washer face scale and male screw). I did put washers the right way (I noticed the washer on the liner scale was a bit bent though). I tried to take apart & reassemble a few times with the same result. Does anyone have a clue of how can I fix this problem?
 
Check youtube, I've seen a couple Zaan take down vids on there. I can't tell you if anything has changed with the new pivot because I haven't had mine apart yet.
 
Thanks I did watch a few YT vids before I took down mine, I assume I did everything right.
 
I tried to straighten it out the best I could (by putting it on flat surface and pressing with another flat surface object). I think it is mostly flat now but the problem remins. Also where can I get some spare washers for Zaan?
 
ridnovir said:
I tried to straighten it out the best I could (by putting it on flat surface and pressing with another flat surface object). I think it is mostly flat now but the problem remins. Also where can I get some spare washers for Zaan?
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Hate to be the bearer of bad news, but new washers will require sending it back to CRK. It's likely that the washer got bent by being in the incorrect position when you tightened the pivot on the first reassembly. :(
 
I disassembled and reassembled my Umnumzaan yesterday as well. I experienced more or less the same result. With the exception that I can open my knife, but with more difficulty. As the OP wrote, you have to tighten the hex screw down inorder to center the blade. If you back off a bit, the blade is not centered. I can open the knife, but my thumb is getting really sore. I'm considering selling this and buying a Sebenza.

Both my washers are perfectly flat.
 
I posted a new thread about the new pivot BEFORE I read this thread and should delete the entry since this thread tells me that the new pivot is new but known about here and at other places...

I had mine apart and experienced zero problems on reassembly (I'm not saying I'm anything special, just that I had no problems). In fact, I feel it's a much easier design to reassemble than the Sebenza since you don't need to try and guide both washers in while aligning the pivot bushing hole. Layed flat with the female end of both handlenaw cure points in place, just lay the blade in place, turn it to free the blade, put the other side of the handle in place, push slightly down, and then tighten to whatever resistance setting you like. I like mine with some slight resistance....cya

JW
 
ColtM1911A1 said:
I posted a new thread about the new pivot BEFORE I read this thread and should delete the entry since this thread tells me that the new pivot is new but known about here and at other places...

I had mine apart and experienced zero problems on reassembly (I'm not saying I'm anything special, just that I had no problems). In fact, I feel it's a much easier design to reassemble than the Sebenza since you don't need to try and guide both washers in while aligning the pivot bushing hole. Layed flat with the female end of both handlenaw cure points in place, just lay the blade in place, turn it to free the blade, put the other side of the handle in place, push slightly down, and then tighten to whatever resistance setting you like. I like mine with some slight resistance....cya

JW
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The reassembly is quite easy I agree. I have backed off a little to allow for easier opening, but my blade is not centered. Is your blade centered?
 
I just got in from the garage as after reading this thread I wanted to take mine apart again. I took it apart yesterday and again just now and haven't had the problem as mentioned above. I picked up some purple loctite today (222MS) low strength today, so I was going to clean it one more time anyway. I used militec 1 grease (very sparingly) and adjusted the pivot with the blade 90 degrees to the handles while keeping the lock bar off of the blade (hope that makes sense), and adjusted it so it had no side play and it is extremely smooth and easy to open. I will admit I had the pivot alittle too tight yesterday, Ridnovir are you sure the pivot is not too tight? And I had no issues with the blade not going back perfectly centered either.
 
A "bent" or warped washer shouldn't really cause much of a problem as it will be pushed flat by the scales and pivot tension. If it has a fold, ding or other physical defect that will not press out then you will get problems.
There is obviously no bushing on the Umnumzaan so you do need to find that "equilibrium" between too tight and a centred blade. It can take some fine adjustments of the pivot but that's how it's done. :):thumbup:
 
Oldbugr said:
Ridnovir are you sure the pivot is not too tight? And I had no issues with the blade not going back perfectly centered either.
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In my case if the pivot is tight the blade is centered but impossible to open; if the pivot is loosened by even a half turn the blade is not centered (skewed to the right face scale) knife opens but not smooth at all. I have noticed that if I loosen pivot a bit and then press scales with my fingers(around the pivot area) blade gets centered then skewed when I release the pressure. Also, if I loosen the pivot a bit more (so the knife is easily opened and closed) than the blade rubs the face scale.
 
Haze said:
A "bent" or warped washer shouldn't really cause much of a problem as it will be pushed flat by the scales and pivot tension. If it has a fold, ding or other physical defect that will not press out then you will get problems.
There is obviously no bushing on the Umnumzaan so you do need to find that "equilibrium" between too tight and a centred blade. It can take some fine adjustments of the pivot but that's how it's done. :):thumbup:
Click to expand...

It almost feels like the lock is too strong and causes the blade to be skewed to the right by pushing on it.
 
GPBob:

Yes, mine is dead center and never moves from that position after I've reassembled the knife. I would suggest you might want to reassemble again and make sure the female pivot is completely flush wit the handle, as well as the male bolt. If that's not the problem, then there has to be something forcing the blade off-center. Check the washers for any minor bending. Be sure that a burr is not present on the washers or anyplace in the areas that mate when the knife is put back together. Check the gaps between parts to see that they are the same on either side of the handles; something is amiss, but with a bit of sleuthing, you should be able to solve the problem....

JW


PS: FWIW, I use fingernail polish on the threads instead of LockTite. To remove, use fingernail polish remover, or cheaper yet, buy a small can of acetone -- it's the same product as the FN remover. It's also a great product for deep cleaning. Just be careful around the cheaper plastics as acetone might just melt the low-grade polymers. Doesn't affect G-10 scales or carbon fibers...
 
I took my Umnumzaan apart again. This time I put a little more of the CRK grease on all contact points. When I put everything back together again, I fiddled with the adjustment quite a bit more than the last time. I finally got the blade centered and it now opens smoothly. I do not have the purple Loctine yet, so it was put together devoid of that adhesive. I hope it hangs in there, because I don't want to take it apart again for a while.
 
A half turn is a LOT on a folding knife's pivot... especially on a knife that's built with 1,000ths of an inch tolerances. Even on BMs & Spydies 1/10th of a turn makes a significant difference.
 
I've had my umnumzaan for over 3 years and have never taken it apart. Was there a problem that required disassembly of the knife?
 
Glad to hear you got everything taken care of:thumbup: I haven't taken my Umnum apart yet but maybe today I'll take a stab at it
 
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