Sunday, August 16, 2015

Take-Down: 111 MRBS

27,21 Asymetrical bearings on the Model 111 MRBS.
More significantly is the curving direction and hence the correct orientation
when putting things back.

Being a bigger knife, it doesn't see as much carry time. Aka less chances of idly flipping and closing on the couch.

While it doesn't bother me too much that it does not drop as fast and smooth as my other Shiros, again it was curiosity that got the better of me like the last take down on the Banner F95.

Anyway after brunch today...

The 111 here has pretty tight tolerance on every movable part. The construction is also quite unlike most other Shiros I have taken apart so far.

Yup, little things like this "holder" to neatly line up the screws are important to me. Even while working on things, a clutter free environment is always a priority.

From the marks left behind on the blade side, it would seem one of the row is barely touching. Still with the remaining 14, it's pretty sufficient. Interestingly its the stepped-in profile on the lock face near the detent ball...

An internal stop-pin design but with a 1/2 and 1/2 channnel. the force of the stop pin located on the plate would still be mostly on metal to metal contact. Not smacking into carbon fiber. Strong as CF are but withstanding forces against their grain isn't their strong point.

... and the reason for the lock face shape. To interface with what's on the blade. Not really new for the 111s, just something I have not noticed till now.

Other than curiosity about the innards, I have always wanted to open this up and see if it can be tuned closer to the feel on my other 111.

The detent is a little stronger on this. Closer look reveal that size of detent ball and location are indeed different. When at lock up, it can be seen the detent is a little higher up as well. A little mental gymnastic of lever-load-pivot-fulcrum, it isn't hard to see why and how all these made a difference now.

Top: 111 MRBS, Bottom: 111 washer
Detent ball size not too apparent but the 111 mrbs one is larger with more exposed area. A smite higher which together with the position (higher up near the recessed area on blade) makes it a little stiffer but the multiple bearings no doubt aids in the centrifugal force when firing the blade open. The washer 111 on the other hand is a well tuned piece of finery that locks into position with an almost surreal sureness. It has to be felt in real, words are just insufficient. To this day, honestly i prefer this over the MRBS 111.

Couldn't help to hold up to check out the milling on the retainers. Compare to many caged retainer bearings on the market, well...

The tight tolerance on the non lock side bearing tells me a few things.. First there is a sandwich plate (I reckon its titanium) between the bearings and the carbon fiber face. The tightness made it not possible to remove the retainer and balls. At least not with the tools at hand now. Still trying to figure this one. So it was cleaning up as much before repacking between the crevices left between the ball and retainer grooves.

A big question in my mind has always been whether it is just the balls that rotate or its both that and the retainer revolving when a blade is fired. A question spurred during one of those blade gatherings by Koji-san. I've always maintained that it's the balls that moved, not the retainer. Any movement in the retainer would only be rather slight.

It is in this regard that I have always tried to re-pack lubes like I would in load bearing applications on other stuff. Trying to get the viscosity right with grease or mix that will "stay" and not be too easily forced out over time which happens to too viscous a lube.

Not a fan of oil lubing alone. That's only something reserved for race day preps on bikes where every microsec counts. Only to be repacked again afterwards. Oil makes everything fast but noisier and will wear things out faster

Anvil's F(x) 38 "Wasabi-Mayo" : 70/30 concoction of Shimano Durace Ace Bearing grease and Chris King Spline lube + a couple drops of ZX1 Micro Oil.

Alright my secret is out. There's a lot of other nice slick lubes out there. Ain't much of a rocket science. Just happen that this works for me on most ball load bearings for a fine balance of things normally associated with such applications.

Let's quit the ramblings and move on...

Getting the amount right and not making a mess is almost a Zen pursuit these days. Having to wipe down is so errm "un-perfect" :)
While putting things back together, it just struck me that if the next 111 outers come in a combination of titanium and carbon fiber with some hollowing out and or 3-D profiling (leaving part of the liner/ back spacer exposed etc?) that could make it pretty rad looking. Ok idea shelved for potential custom project.

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