Quick question on my Umnum...

13aphomet

13aphomet

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Joined
Feb 7, 2012
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880
Hey guys, got a badass Startac Umnumzaan from back in 2010, or 2011, cant remember. No LBS, old pivot, s30v.. etc..

I have the takedown tool.. The problem I'm having is that when I take her down and put her back togeather; if I tighten the pivot until the blade is centered, it's FAR too tight to even open. For the action to be smooth, the blade has to be pretty off center.
Is this normal for the early ones? Any tips/tricks I could try?

Also, even when I do have the action looser, it's not very smooth. Now I know it's not going to be as smooth as say, my Regular Sebenza because of the bushing system.. but would also appreciate any input on this.

Such a great knife in every respect. Just wanna get this baby fine tuned!!


 
Very nice looking knife. With regard to the pivot, have you made sure the washers are in there correctly? That's all I can think of.
 
Yah, I mean, I'm not sure what side should be facing what, but I've had it apart and together a quite a few times..
Maybe I'm just nit-picking, but when you look down the blade, from the jimping; it def looks off center. From the front view, it just looks a little off center.
 
Definitely check the washers and make sure everything is fitted right. After that, you just need to tune the pivot to find the sweet spot where the ease of deployment and no side to side wiggle meet
 
Oh I def do that. Everything is tight, deploys easy, no side to side play.. blade just doesn't sit centered.
When I center it, it's so tight it's next to impossible to deploy.
 
A while back I picked up a startac umnum that had the blade replaced with a TNK Tanto blade... I thought it was the baddest thing ever (still do Lol) but the centering was way off.

What I did to get it to line up and still open easily was to polish the scales and pivot washers. Not the entire scale just the part that touches the pivot bushings.

On reassembly I slowly snugged up the pivot and the rear hex bolt very slowly until they had just a tiny bit of resistance. I then checked the blade play at the tip while closed... a fair bit of side to side play at this point but it would fly open! A little more tightening until i found a combination of acceptable front side to side movement and easy deployment.

It opens very smoothly and has just the teeniest bit of side to side at the tip while closed. There is zero side to side play at the tip while open, none at all. You'll have to try this to see what i'm talking about.
 
With an older knife, it makes a difference if the washers are not put back exactly like they were taken out. That's due to the washers forming to the blade/handle. If too much grease/lube is put on, the washers will not seat properly and make the blade off center. I've learned to use the CRK grease sparingly. It doesn't take much at all. If it feels gritty after assembly, I would think one or both of the washers are flipped. I've never been able to tell which side goes where by just looking at them.
I've honed the washers on one of my CRK because it still felt gritty after it was put back together, the blade wasn't off center. I figured I screwed up on putting the washers back and didn't get them right. I would not recommend that to anyone.
You can always send it in to get new washers put on if you can't resolve the issue.
 
make sure the gritty feeling isn't from the detent, mine has the gritty feeling from time to time due to pocket lint or some foreign particle lodging itself to the detent path, that makes the action gritty enough that you'll clench a certain orifice when you open the knife :p
 
I've got a star-tac Umnum that looks like its off center by the tiniest bit but in reality it's not. It drove me crazy trying to figure out why. I spent hours flipping washers and screws. It drove me so crazy I ended up busting out some feeler gauges. That's when I discovered that it actually was centered but didn't appear to be. The problem is that the lock-bar doesn't sit parallel to the blade and handles when closed. So when looking down the knife the lock-bar side appears closer and is closer up until after the lock-bar cutout. After that point the handles are parallel but the swedge on the end of the blade makes it hard to see if the blade is centered or not. I would suggest turning the knife over and looking at the back side of the handles where they are actually parallel. Hope all that made sense...:confused:;)
 
I'll give it a shot.. worst case scenario, I still have a blazingly awesome knife. Or I can send it to the spa.
I'll just keep tinkering till then..
Good info though guys, Thanks you!!
 
Hey Phomet,

I had the exact same problem, Either wayyy too tight or too loose and off centered. Although I do have the new pivot (tanto version).

Here is what to do:

1. PUT LOCTITE ON THE THREAD
2.Tighten it all the way until the blade is centred.
3. SLIGHTLY turn the pivot counter clockwise until it is loose enough to open BUT STILL HAVE RESISTANCE.
4. Put a little bit of the oil provided and open and close it for a few hours. You may want to hold the blade between your thumb and index finger, as my thumb was blistered from using the thumb stud. As you have probably noticed, this folder opens a little different than a conventional folder. Mine took a day or so, but now opens with a flick of my thumb at the speed of an auto.
Not sure if the "older" version comes with oil and loctite, if not, get some and put very little on the thread.
 
When I first got my Zaan, it was pretty tight. Took a few days of constant flipping to get it smooth like butter. Maybe if yours wasn't used much before, it just isn't broken in? I know you have taken it apart multiple times but have you washed all the parts? Not just wiped down but washed? I used mine to cut up an apple once and I guess some juice got in there. Totally messed up the action. I didn't clean it for a few days just to see if it would clear itself. Nope. I had to take it apart and wash everything with soap and water. Then lube and assemble again. Back to new.
 
Also, check the orientation of the pivot pieces. They normally come from the factory with the female ends coming through the scales from the lock side. That way you can lay them on the lock side and take them apart without flipping the knife from side to side. Makes it easier.

I've had to change the side the female pivot enters the knife scale on with a couple of Sebenzas to get them perfectly centered, which is a pet peeve of mine. No big deal, just takes some time and the end result is all of mine are perfectly centered. When I take them apart to clean I lay the pieces out in exactly the order and orientation I removed them to ease reassembly.

Lastly, be careful with the short side of the Allen wrench rotating around and rubbing against the scale of the Zaan when using it to rotate the take-down tool. I learned this the hard way.

I'll cover it with electrical tape or painter's tape next time as I slightly scratched an otherwise pristine Zaan I received the other day and I should not have allowed that to happen.
 
You could always try the old framelock centering trick that many of us Hinderer fans use to center up our XM-18s.

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

-Close the blade and loosen the rear standoff screw so that it isn't cinched tight, but still holds the frame together.

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

-While pulling blade, tighten the standoff screw.

-Loosen the pivot and adjust it to the desired tension/centering.

It works well with Hinderers, might work well with an Umnum too as I've used it other framelocks with success.

Good luck.
 
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