Thoughts on centering an Umnumzaan

R

rlarsen462

Joined
Dec 26, 2005
Messages
145
Hey guys,

Recently bought a slightly used Umnumzaan with the older pivot that I could carry without guilt. :D

Unfortunately it's pretty offcenter visually (doesn't touch the scales) and my OCD is driving me nuts about it...both my small Sebenza and Ti-Lock are dead center.

I've taken the knife apart a couple of times now following all the various advice I've read on the forums and elsewhere on the internet, but I just can't get this thing centered. Are there any unorthodox ideas out there I can try before I give up and send it to CRK?

Call me silly all you want, but it's one of those things that hurts my enjoyment of a knife, especially one as cool and otherwise perfect as this one.

Thanks in advance!
 
Try this?

RubiconSS said:
Centering the Blade:


Here we go:

1. Open blade to 90 degrees and tighten pivot so that it is really tight.

2. Close the blade and loosen frame screws so they aren’t tight, but still holding the frame together.

3. While the blade is still in the closed position, pull blade towards the side you want the blade to move.

4. While pulling blade, tighten the frame screws. (Note: Using a folded business card or the like wedged in between the liner and blade to Hold position works well).

5. Loosen the pivot and adjust it to the desired tension.
Click to expand...

[source]
 
My old-model Zaan is similarly off-center (unlike the two old-style Star-tacs I just got). Unfortunately, with the tight tolerances that CRK has on it's scales, pivots, and standoffs, as well as the Zaan only having one standoff, this method hasn't worked for me. When I find some time, I'm going to send it in to CRK to get the scales re-blasted (it came a little scotch-brited), and I'll ask them to do what they can about the centering.
 
Could it be that the blade or blade grind is off rather than the actual fit of the knife ? It's not common but has happened, it could be that it was bent slightly by the previous owner.

The centering on the Umnumzaan is pretty straight forward. The pivot has a long thread so the sweet spot is usually on either side of a tiny adjustment. If you tighten the pivot right down is the blade still off ?
 
With mine, I'm pretty sure (but not positive) that the pivot hole is not normal to the blade flats. It's not a calibrated tool, but I took a steel ruler to the flats of the blade, and they both seem flat. The grind is also very even. But when I inspect the space between the blade and the non-locking scale (when closed), it is wider near the pivot and thinner near the tip.

It is very minor, but the blade as a whole seems closer to the non-locking scale than the locking scale, so the slight un-parallelness is more apparent than it otherwise might be.
 
rlarsen462 said:
Hey guys,

Recently bought a slightly used Umnumzaan with the older pivot that I could carry without guilt. :D

Unfortunately it's pretty offcenter visually (doesn't touch the scales) and my OCD is driving me nuts about it...both my small Sebenza and Ti-Lock are dead center.

I've taken the knife apart a couple of times now following all the various advice I've read on the forums and elsewhere on the internet, but I just can't get this thing centered. Are there any unorthodox ideas out there I can try before I give up and send it to CRK?

Call me silly all you want, but it's one of those things that hurts my enjoyment of a knife, especially one as cool and otherwise perfect as this one.

Thanks in advance!
Click to expand...

If you drop it off to me at work I can straighten it out for you and drop it by your house when I'm done. I can also bead blast it if that interests you at all.
 
I've tried the technique above as well as several different orientations of the washers, etc. and nothing seems to correct it. When it's cranked so tight the blade cannot be deployed, it's nearly centered but that's as close as it gets.

1SHOT, I might take you up on that offer...what would you propose to do to get it centered?
 
rlarsen462 said:
I've tried the technique above as well as several different orientations of the washers, etc. and nothing seems to correct it. When it's cranked so tight the blade cannot be deployed, it's nearly centered but that's as close as it gets.

1SHOT, I might take you up on that offer...what would you propose to do to get it centered?
Click to expand...

I have a myriad of things to try...maybe you've tried them I don't know. I have never had an Umnumzaan that I can't center though...and I just might be more OCD about it than you... :D

(I have actually taken calipers and measured the frame ID and halfed that DIM and made sure the point of the blade was at the tip of my calipers...Brown and Sharpe Swiss calipers that I have had calibrated...)
 
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