Suggested/Factory Angle not Jiving w/Sharpie?

[cbwx34]

JDS,

Are you checking both sides of the knife and seeing this (or in other words, is your knife vertical in the clamp)? I ask this because something looks really off in your setup. It’s hard to tell from your pictures, but, especially in the first picture you posted… it looks like there’s a huge gap between the two sides, and there shouldn’t be. The space between the clamps basically should be about the same width as the knife, and there shouldn’t be such a big gap and overhang that I’m seeing… unless I’m not looking at it right.

To answer your other question, what most makers say there knife is sharpened at and what they actually are is often different, although I don’t know if that’s true with a “Hinderer”. At this point though, I’m more interested in why the clamp setup looks like it does.

[Mikedoh]

Curtis
I’d noticed the clamp looking out of whack myself and thought it was just a mock up to show angle gauge use. If that is in actuality the way the knife is clamped, something is definitely off there.

[Todd Klimek]

Maybe I’m seeing it wrong, but the knife doesn’t even look like its in the clamp and the clamp doesn’t look square to the base, is that an optical illusion?
Ahhh..I see, its clamped (duh). Sorry….

Todd in Chicago

[Jonny]

Good eye on the clamp. As I repositioned the arms I did indeed notice the clamp was way too far out on the bottom and corrected it but still way off (I think) in my angles. I think it looks more out of whack from that photo-angle than it really is but i’ll do some checks.

So not to beat a dead horse but maybe I could just ask about your set-up procedure…

Say you want to sharpen a knife with a 22 degree factory angle and keep that factory angle. You position it in the WE, set angle of arms/stones to 22. Say you did a “sharpie test” as well but marker is removed from bottom of edge. You’re saying you just go ahead with sharpening anyway, “forcing/re-profiling” the edge to YOUR specifications (or 22 degree angle)? So essentially if you did another sharpie test at the end of your session the marker would now be removed from the edge and I guess the knife did not have a true 22 degree angle to start with?

And just FYI, i’m not really practicing on the Hinderer, just doing some light test swipes with a high grit because it’s the one knife where I know the correct factory angle. I have a box of practice knives i’m using.

I’ve done about ten knives and believe it or not they’ve come out pretty good just using the sharpie to match the angle. But the discrepancy between what i’m seeing most edges sharpened at and what MY readings are is bugging me.

Again, it seems like if I have a knife at “X” factory angle and I set my arms to match “X” angle I should be removing marker pretty close to the apex, not the bottom. Is that NOT common?

Thanks for all the help, I really appreciate it!

[tcmeyer]

Sorry guys, but I have a real problem picking up on what you’re seeing in the clamp set-up in the last photo. I thought I could see that the opening between the two sides was wider at the bottom than the top, so I blew the photo up in a “Photoshop” app, boosted the brightness and the two sides look pretty close to parallel, which would be correct.

Of course the user has to watch carefully to make sure the knife is clamped vertically and is not leaning to one side or the other. I looked at a bunch of photos of Hinderer XM-18 knives and it looks as if all have at least a small amount of flat where they’d be clamped. Ah, but I’m assuming here… My practice is to clamp ALL folding knives with the bolster pushed up against the clamp. I’ll explain that elsewhere.

As the thickness of the blade increases, (say, a machete as opposed to a filet knife) the centerline of the knife (the line that the apex should fall on) moves by one-half of the thickness change. The apex moves away from the fixed side and towards the free side. This means that the angle will increase on the fixed side and decrease on the opposite side. The Hinderer has a thickness of about 0.180″, so the theoretical center of the blade would move 0.090″. But compared to what? I measured a setup with my Buck 110 folding knife.

At the 22 degree detents, I measured 2.66″ horizontally between the center of the ball joints and the center of the blade ( 0.12″ thick”)

I measured 4.85″ vertically between the centerline of the ball joints and the apex of the blade over the center of the vise. This is the adjacent side of my triangle.

I measured a couple of diamond blocks and found them to be about 1.187″ thick, resulting in an offset of 0.594″. This means the base (opposite side) of my triangle is 2.067″.

My Navy training trig says the tangent of my triangle is 2.067 / 4.85 = .426. The included angle (arctangent=0.426) is actually 22.54 degrees. My angle cube says 22.6 degrees. As near as I can see, both sides are identical.

Now if we switch to a Hinderer XM-18, which has a thickness of 0.185″ the vertical centerline of the knife will move 0.033″ to the right. This means that my triangles are no longer identical. Theoretically, the angle on the left becomes 22.9 degrees and the angle on the right becomes 22.2 degrees.

Not enough of a difference to worry about, but if you go to something thicker, the angle change does become a factor. I don’t know if it would be noticeable on the finished knife.

Attachments:

• brightnessboost.png

[Jonny]

Tried to get a “straight-on” pic

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• IMG_0098ReSize.png

[tcmeyer]

Sorry guys, but I have a real problem picking up on what you’re seeing in the clamp set-up in the last photo. I thought I could see that the opening between the two sides was wider at the bottom than the top, so I blew the photo up in a “Photoshop” app, boosted the brightness and the two sides look pretty close to parallel, which would be correct.

Of course the user has to watch carefully to make sure the knife is clamped vertically and is not leaning to one side or the other. I looked at a bunch of photos of Hinderer XM-18 knives and it looks as if all have at least a small amount of flat where they’d be clamped. Ah, but I’m assuming here… My practice is to clamp ALL folding knives with the bolster pushed up against the clamp. I’ll explain that elsewhere.

As the thickness of the blade increases, (say, a machete as opposed to a filet knife) the centerline of the knife (the line that the apex should fall on) moves by one-half of the thickness change. The apex moves away from the fixed side and towards the free side. This means that the angle will increase on the fixed side and decrease on the opposite side. The Hinderer has a thickness of about 0.185″, so the center of the blade would be 0.090″ from the fixed jaw. But compared to what? I measured a setup with my Buck 110 folding knife.

At the 22 degree detents, I measured 2.66″ horizontally between the center of the ball joints and the center of the blade ( 0.12″ thick”)

I measured 4.85″ vertically between the centerline of the ball joints and the apex of the blade over the center of the vise. This is the adjacent side of my triangle.

I measured a couple of diamond blocks and found them to be about 1.187″ thick, resulting in an offset of 0.594″. This means the base (opposite side) of my triangle is 2.067″.

My Navy training trig says the tangent of my triangle is 2.067 / 4.85 = .426. The included angle (arctangent=0.426) is actually 23.1 degrees. My angle cube says 22.6 degrees. As near as I can see, both sides are identical.

Now if we switch to a Hinderer XM-18, which has a thickness of 0.185″ the vertical centerline of the knife will move 0.033″ to the right. This means that my triangles are no longer identical. Theoretically, the angle on the left becomes 23.4 degrees and the angle on the right becomes 22.7 degrees.

Not enough of a difference to worry about, but if you go to something thicker, the angle change does become a factor. I don’t know if it would be noticeable on the finished knife. Could you offset the errors by moving the ball joint assemblies plus or minus one degree?

[Jonny]

Sorry guys, but I have a real problem picking up on what you’re seeing in the clamp set-up in the last photo. I thought I could see that the opening between the two sides was wider at the bottom than the top, so I blew the photo up in a “Photoshop” app, boosted the brightness and the two sides look pretty close to parallel, which would be correct.

Of course the user has to watch carefully to make sure the knife is clamped vertically and is not leaning to one side or the other. I looked at a bunch of photos of Hinderer XM-18 knives and it looks as if all have at least a small amount of flat where they’d be clamped. Ah, but I’m assuming here… My practice is to clamp ALL folding knives with the bolster pushed up against the clamp. I’ll explain that elsewhere.

As the thickness of the blade increases, (say, a machete as opposed to a filet knife) the centerline of the knife (the line that the apex should fall on) moves by one-half of the thickness change. The apex moves away from the fixed side and towards the free side. This means that the angle will increase on the fixed side and decrease on the opposite side. The Hinderer has a thickness of about 0.180″, so the theoretical center of the blade would move 0.090″. But compared to what? I measured a setup with my Buck 110 folding knife.

At the 22 degree detents, I measured 2.66″ horizontally between the center of the ball joints and the center of the blade ( 0.12″ thick”)

I measured 4.85″ vertically between the centerline of the ball joints and the apex of the blade over the center of the vise. This is the adjacent side of my triangle.

I measured a couple of diamond blocks and found them to be about 1.187″ thick, resulting in an offset of 0.594″. This means the base (opposite side) of my triangle is 2.067″.

My Navy training trig says the tangent of my triangle is 2.067 / 4.85 = .426. The included angle (arctangent=0.426) is actually 22.54 degrees. My angle cube says 22.6 degrees. As near as I can see, both sides are identical.

Now if we switch to a Hinderer XM-18, which has a thickness of 0.185″ the vertical centerline of the knife will move 0.033″ to the right. This means that my triangles are no longer identical. Theoretically, the angle on the left becomes 22.9 degrees and the angle on the right becomes 22.2 degrees.

Not enough of a difference to worry about, but if you go to something thicker, the angle change does become a factor. I don’t know if it would be noticeable on the finished knife.

See, i’m getting about 26 degrees on my cube/arms to remove the sharpie from the edge of the Hinderer?

[Wesley]

So your cube is saying 22*, and you arms are setting on the 26* mark?

[Mikedoh]

TC
First photo is referenced. See post

[Jonny]

So sorry, work schedule got crazy, sharpening went on hold but still confused.

@”Wes74″: No, cube and arms match, I guess you’d say “factory angle” and arms/cube DON’T match.

Again, if I mount a knife w/a factory 22 degree angle, my arms are out at about 26 degrees to remove marker from the edge w/the Sharpie test. I was assuming if I mounted a 22 degree edge my arms would be at about 22 degrees accordingly, not at 26 degrees… is that not the case?

Is that common for arms/edge degree to be so far apart but still remove the marker correctly?

That is where i’m confused. Thx.

[tcmeyer]

So JDS:

You’re saying that the Angle-Cube is reading 22 deg when the arms are in the 22 degree detents. The problem is that to match the “as-is” factory angle (and remove the marker at the apex), you have to move the arms out to the 26 deg setting. Correct?

I’ve never held one of these very expensive knives in my dirty fingers, so I can’t say for sure that the factory actually sharpens to an accurate angle, as we can with our Wicked Edge fixtures. That said, for more run-of-the-mill knives, at the end of the knife manufacturing process, a fellow (usually the final polisher) touches the edge to a sanding belt to set the bevels, then goes to a polishing wheel to dress up the cutting edge. The final inspection will be for manufacturing flaws and for an “apparently sharp” edge before placing the knife in its presentation box. I don’t believe that anybody checks to see if the edge is beveled to 22 degrees. So as I and others here have said, it’s common for factory edges to be something other than some “specified” angle.

I think the consensus here is that the factory edge in your case is simply not as advertised. Is it possible that somebody along the line has incorrectly resharpened the blade to 26 degrees?

Why are you being asked to sharpen the blade? Is it just in need of routine sharpening? Tell your customer that the existing bevel angle is not correct and ask him if he wants you to re-set the bevels to the factory spec of 22 degrees.

If the knife is not a working knife, but rather is kept for display or collector purposes, the customer might prefer that you just dress up the 26-degree bevels. Or perhaps the incorrect bevel angle simply cries out for a correction?

[Jonny]

Yes, you hit it on the head, factory angle simply not matching arms/cube.

Obviously I’m experiencing either two problems, a set-up problem or all the knives im practicing on are all a bit “off”. I’m getting what I think are high degree readings on ALL knives i’ve practiced on. Most simple folders seem to be in the 18-22ish degree range but i’m always like 25+? I did a test on a kitchen knife which I (i’m obviously no Pro) think should be sub 18 degrees or so and i’m in the 20″s. So again, something seems wrong with set-up.

That’s why I did a light test on the Hinderer as I know the factory angle is 22 degrees and I was hoping a high-end knife would be of close tolerance thus eliminating the “incorrect factory angle problem” redirecting my problem again to set-up… or maybe there’s no problem at all and the difference in degrees is common?

Something just doesn’t seem to be jiving and my angles just seem too high on everything, I keep feeling like it’s a stupid-Noob set-up mistake.

[Jonny]

So I just tried to practice mounting a cheap “Kershaw Outcast” style imitation just to see if I could start getting my head around a knife of that length and curvy shape. Not sure if this is right but i split the knife in half and tried to tackle it in two phases (front/rear).

As you can see in pic, right off the bat in the front half i’m at 31 degrees to remove the Sharpie from the edge correctly. Doesn’t that seem very high?… maybe the pics will reveal something.

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• IMG_0131ReSize300.png

[Jonny]

Pic #2

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• IMG_0133ReSize300.png

[Author]

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