Tuning a new Benchmade Axis (or just about any similar production folder)...

[Professor]

PART 1:

This may be old hat for most of you, but I find that I have to perform this procedure every now and again to increase smoothness of opening/closing of some production folders, as well as to correct tolerance imperfections from the manufacturer. I've had to do this with folders from NIB Benchmades to Spyderco's to Bokers to CRK's (CRK's to a much lesser degree, as one might imagine). I thought folks new to tinkering might find it interesting; I do not by any means suggest it's the only way to skin the cat, just one that has worked well for me over the years.

In this instance, I purchased a new Benchmade Model#527 Small Pardue Presidio Axis folder for a good buddy's Birthday at the end of this month. The dealer where I purchased it from engraved my friend's name on the backside of the blade:



On this particular model, the action was tight and gritty, but what bothered me the most was the gap between the stop pin barrel and the right liner as seen in this picture:



In my experience, the stop pin or stop pin barrel in this case dictates the necessary space needed all the way around the inside of the folder, since in this case, with this barreled stop pin design, it's width cannot easily be adjusted. Far more easily adjusted are the width/thickness of the backspacer and that of the blade tang/washer combination. After complete disassembly of the folder, I took thickness measurements of all variables, measuring the backspacer in several places along it's length, always making sure to zero my caliper between measurements:



To be continued...

 

[Professor]

PART 2:



You'll see that the blade tang with the two bronze washers on each side was the thickest of the three measurements, which explains the gap that existed between the stop pin barrel and the right liner.

To remedy this, I gave the bronze washers the "CRK Treatment," as seen in their Exquisite Blade video. Essentially I stated with 1200 grit sandpaper, laid on a perfectly flat surface, and with my index finger swirled the washers on each side approx. 10 rotations, and then took another measurement, careful to not remove too much material too fast:



To be continued...

 

[Professor]

PART 3:



Your index finger will start to look like this if you're doing it correctly and removing enough material:



As you approach the thickness you're looking for, do a brief polish on the 1500 grit or higher (1500 grit was as fine a grit as I had available, but does the trick nicely), just to really shine the washers up, but of course being careful not to remove too much material. In this instance, I wanted to take the blade tang/washers thickness to exactly this measurement, which is everso-slightly less than that of the stop pin barrel thickness:



To be continued...

 

[Professor]

PART 4:

The next step(s) is to re-assemble, checking to see if tolerances and initial smoothness have improved. If not, disasseble again and repeat the process. You'll learn that not all pieces need to be re-assembled to check certain tolerances -- a real time and headache saver.

In this case, I knew I was in the ballpark when I saw this (the fit between the stop pin barrel and liner was now flush):



Now that everthing was flush (the backspacer in this instance of course being the thinnest of the three thicknesses, and the one I cannot adjust since I can't make it thicker, without replacing with a new, thicker part(s) -- I can live with it in this case), it was time to increase smoothness.

Using my favorite, longest-lasting pivot lube (good ole CRK flourinated grease), I applied it sparingly to the surfaces shown, on both sides of the blade tang, inside the pivot hole, and along the blade tang spine where the Axis module makes contact:



After final re-assembly with Loc-Tite on all screws, setting what I'd call my ideal pivot tension, this Axis folder is ready to grace my friends pocket as a trusted EDC. The tolerance are tight, and after cycling approx. 50 times, the action is super smooooooth:



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There are many complaints of out-of-the-box fit and finish issues with production knives, and most rightly so. Finish issues in my experience are far more difficult to fix on your own, and probably need to take a trip back to the manufactuer for correction or replacement. Many fit issues, as in the case of this BM Axis folder that I bought for my friend, are within many folks' capabilities to correct themselves with minimal tools and the time, patience, and desire to do so. I enjoy tinkering, so for me minor surgery such as this was therapeutic.

With many sub-$200 production knives, barring finish issues that I cannot correct, I view them as a starting point out of the box. I've seen similar issues with knives costing far more.

In Benchmade's case, they utilize wonderful materials and mechanisms, and while they typically do a great job of internal QC with fit and finish, sometimes their knives (like most production knives) need a loving, helping hand from the end user.

Thanks all.

Prof.

 

[Nullity]

So, originally, the liners weren't perfectly parallel and they were sitting at a slight angle against the washers/tang, causing non-uniform pressure against the washers/tang?

Now everything is parallel and mating perfectly without any hot-spots on the moving parts?

Tell me if I'm missing something.

 

[Professor]

So, originally, the liners weren't perfectly parallel and they were sitting at a slight angle against the washers/tang, causing non-uniform pressure against the washers/tang?

Now everything is parallel and mating perfectly without any hot-spots on the moving parts?

Tell me if I'm missing something.

That's pretty much it. The blade/washer combo was thicker than it was supposed to be, and sanding the washers down brought it within specs of the stop pin. Go significantly thinner than the stop pin, and you've got the same problem in reverse.

Prof.

 

[Nullity]

That's pretty much it. The blade/washer combo was thicker than it was supposed to be, and sanding the washers down brought it within specs of the stop pin. Go significantly thinner than the stop pin, and you've got the same problem in reverse.

Prof.

Can you do a post of how you make the washers thicker?

 

[Professor]

Can you do a post of how you make the washers thicker?

Just put some chewing gum on them.

In that instance, you've got to start with the thickest point, either the stop pin/stop pin sleeve, or the backspacer or standoffs and start slimming them down. I've had to do that with CRK's, where both the stop pin sleeve and the backspacer were significantly too thick. Luckily, the backspacer was silver, as were my dual thumblugs, so sanding it and the stop pin sleeve in the same manner as the washers above to a uniform thickness was not traumatic.

CRK's with their robust ti slabs can have an acceptible amount of micro-deviation between the blade bushing and washers, stop pin sleeve, and backspacer, but it was unacceptible and problematic when mixing a custom (and more flexible) G10 front slab into the equation.

Prof.

 

[Nullity]

Is there any easy way to lessen the width of the center section of a shouldered stop-pin?

 

[Professor]

Is there any easy way to lessen the width of the center section of a shouldered stop-pin?

Not that I know of. That's what I woulda been facing with the Benchmade had the shouldered (what I call a "barreled") stop pin been the thickest point, changing the type of problem, but nonetheless still having been a problem all the same.

Not sure how you'd solve that one, short of somehow turning and shaving away at the shoulder until you get what you need. Or perhaps othewise remanufacturing it altogether to the correct specs. That would be an ugly process, and I'm glad that to date, I've found most problems lie with the blade/washers being the thickest point and problem child.

 

[Professor]

PS Nullity, 193 posts since '02? Where the hell have you been all my life?

It's good to communicate with like (omni-directional yet twisted) minds. Best to you and your family, Sir.

Prof.

 

[Nullity]

I dunno. I found out how to search, and just never socialized on the forums.
Life got in the way a few times... I think I was 17 when I joined.

Your avatar also reminds me that only recently have I started to respect Loveless' designs, so maybe it was best I waited until now, haha.

Nice talking with you too.