non-perforated washers

all i can say is it may have been a shot at perfecting perfection, but Chris nailed it with the 25 (IMO).
 
SuzukiGS750EZ said:
Just cleaned mine tonight. Can't say it trapped grit and grime, but all of my grease was missing lol.
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That (both) has been my experience, which makes me wonder whether it really provides any noticeable benefit. If it does, I didn't notice. ;) :) I'm not criticizing the move to perf'd washers, just not seeing a whole lot of upside, either.
 
I've never held another sebenza so i have no media to compare to. It seems like the CRK grease just dries up and gets sticky. There was a very thick film of grease left when i pulled the knife apart. I don't think they're a bad set of washers, but since the tolerances are so tight, what are the odds of any particulate getting into the washers?
 
Well, thanks to MVG I have a set of solid washers to try with my large 21. He sent them with the pivot bushing and stop pin collar. Unfortunately, I'm not sure they'll be directly comparable, because of the various variables that all the components contribute to the pivot feel. Using the solid washers and accompanying bushing, the blade was very stiff, but that seems to be caused by the bushing having a very tight fit to the blade tang, so the drag is on the bushing surface. I switched to the bushing that came with the knife with the solid washers, and the knife is just as smooth as before. But the blade is noticeably looser (holding the lock-bar off the tang, it drops freely, whereas with the stock washers it needed a slight nudge). My calipers show no difference in thickness between these older style solid washers and the perforated washers that came with my knife, both measure 0.0160" (my calipers measure to 0.0005").

So, I'm pretty surprised. Unless I'm missing something, the stack-up between the washers+blade and pivot bushing shouldn't have changed. And yet the blade will fall with gravity when the lock-bar isn't pressing against it. I would not have expected that big a change. Given how much the slightest pivot tension change can affect the blade movement, I'm willing to accept that there could be something else causing this change.
 
I'm gonna take it apart tonight and take some more comprehensive measurements to see if there is a difference with the dimensional stack-up.
 
I've been collecting, using, and abusing the Sebenza for about 18 years. Within the last year and a half I've noticed a big difference in deployment smoothness. Not saying the perf washers are the reason, just saying. There use to be a "break in period" for smoothness. Now most if not all come this way out of the box.
 
blackend said:
I've been collecting, using, and abusing the Sebenza for about 18 years. Within the last year and a half I've noticed a big difference in deployment smoothness. Not saying the perf washers are the reason, just saying. There use to be a "break in period" for smoothness. Now most if not all come this way out of the box.
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I guess the question is whether the out-of-the-box smoothness is due to finer tuning at the factory or merely changing to perforated washers.
 
MRaymond said:
You may be right. I just don't see anything "gunky" getting in between the blade and washer when the pivot is tightened down to an adequate tightness. There is just no room for anything other than liquid. I thought the perforated washers were meant to hold grease, not give room for any particulate matter room to escape.
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I bought a used Sebenza once that had never been cleaned. There are tons of gunk that can get in there. I ended up ordering new washers for it.
 
Old hardware:
solid washer + blade tang + solid washer = 0.1530"
old pivot bushing width = 0.1535"
old pivot bushing diameter = 0.3165"

Stock hardware:
perforated washer + blade tang + perforated washer = 0.1535"
stock pivot bushing width = 0.1535"
stock pivot bushing diameter = 0.3160"

So. The solid washers stack-up with the blade half a mil under either pivot bushing, allowing the free swing that I described. The stock perforated washers stack-up exactly with the pivot bushings, allowing very smooth operation, but not free swinging. However, the old pivot bushing has a slightly larger diameter which binds the blade enough so that with either set of washers it feels tight.
 
Nice research. Interesting. Wonder why my large Tanto doesn't swing as free as my large cf inlayed with the same washers?
 
Yeah, I mean these are all 5 ten-thousandths of an inch variations... very small. I forgot to add my conclusion that given these dimensional differences and behavioral differences, that I think that the changes in the blade movement are due to these slight variations and not the perforation/solid feature of the washers. That's not to say that the perforations don't make a difference, just that this example probably doesn't prove anything one way or the other.
 
All the blades are milled to a specific thickness as well. Be it a thou of inch difference or not makes a difference. Just part of the equation.
 
Remember too that the pivot bushing is hand rubbed down to fit proper. Hand tuning will effect swing smoothness.
 
Just for clarity, the new hardware wasn't fitted at CRK to the specific knife?

Muaddib1116 said:
Old hardware:
solid washer + blade tang + solid washer = 0.1530"
old pivot bushing width = 0.1535"
old pivot bushing diameter = 0.3165"

Stock hardware:
perforated washer + blade tang + perforated washer = 0.1535"
stock pivot bushing width = 0.1535"
stock pivot bushing diameter = 0.3160"

So. The solid washers stack-up with the blade half a mil under either pivot bushing, allowing the free swing that I described. The stock perforated washers stack-up exactly with the pivot bushings, allowing very smooth operation, but not free swinging. However, the old pivot bushing has a slightly larger diameter which binds the blade enough so that with either set of washers it feels tight.
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The Stock hardware is the washer/bushing set that came with my large 21 from the factory. The Old hardware is the old solid-washer/bushing set that MVG sent me. The blade is obviously the blade that came with the knife from the factory.
 
I am glad the solid washers were helpful in your research. It appears CRK made the perforated washers slightly thicker, perhaps to maintain the same stiffness with the holes.

This means CRK must have removed some material (.0005) from my large S30v Regular Sebenza, either from the blade or handle before fitting the new perforated washers.

Nicely done Muaddib1116....
 
MVG said:
It appears CRK made the perforated washers slightly thicker, perhaps to maintain the same stiffness with the holes.
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I'm not so sure about this... 0.0005" is very small. My calipers' smallest increment is 0.0005" not 0.0001", so the variation might be slightly less or more and my device is rounding. Having such a small variation on a 3 component stack-up is very impressive, and I'm guessing the variation is well within whatever tolerance stack-up CRK uses.

Unfortunately, I don't think my findings were very conclusive, at least not in regards to the functionality of the washer perforations. I appreciate the kudos, but I'm not sure they are deserved.
 
But, again, for clarity, one set was not fitted by CRK, correct?

Muaddib1116 said:
The Stock hardware is the washer/bushing set that came with my large 21 from the factory. The Old hardware is the old solid-washer/bushing set that MVG sent me. The blade is obviously the blade that came with the knife from the factory.
Click to expand...
 
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