Welcome, Guest
Username: Password: Remember me

TOPIC: Suggested/Factory Angle not Jiving w/Sharpie?

Suggested/Factory Angle not Jiving w/Sharpie? 8 months 6 days ago #15203

  • JDS
  • JDS's Avatar
  • OFFLINE
  • Senior Boarder
  • Posts: 49
  • Karma: 1
Tried to get a "straight-on" pic


IMG_0098ReSize.png
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 8 months 6 days ago #15204

  • tcmeyer
  • tcmeyer's Avatar
  • OFFLINE
  • Gold Boarder
  • Posts: 251
  • Thank you received: 200
  • Karma: 22
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?
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 8 months 6 days ago #15205

  • JDS
  • JDS's Avatar
  • OFFLINE
  • Senior Boarder
  • Posts: 49
  • Karma: 1
tcmeyer wrote:
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.

brightnessboost.png



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?
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 8 months 6 days ago #15206

  • Wes74
  • Wes74's Avatar
  • OFFLINE
  • Junior Boarder
  • Posts: 21
  • Thank you received: 4
  • Karma: 5
So your cube is saying 22*, and you arms are setting on the 26* mark?
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 8 months 5 days ago #15208

  • Mikedoh
  • Mikedoh's Avatar
  • NOW ONLINE
  • Platinum Boarder
  • Posts: 466
  • Thank you received: 117
  • Karma: 14
TC
First photo is referenced. See post
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 7 months 3 weeks ago #15328

  • JDS
  • JDS's Avatar
  • OFFLINE
  • Senior Boarder
  • Posts: 49
  • Karma: 1
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.
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 7 months 3 weeks ago #15330

  • tcmeyer
  • tcmeyer's Avatar
  • OFFLINE
  • Gold Boarder
  • Posts: 251
  • Thank you received: 200
  • Karma: 22
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?
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 7 months 3 weeks ago #15331

  • JDS
  • JDS's Avatar
  • OFFLINE
  • Senior Boarder
  • Posts: 49
  • Karma: 1
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.
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 7 months 3 weeks ago #15333

  • JDS
  • JDS's Avatar
  • OFFLINE
  • Senior Boarder
  • Posts: 49
  • Karma: 1
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.

IMG_0131ReSize300.png
Last Edit: 7 months 3 weeks ago by JDS.
The administrator has disabled public write access.

Suggested/Factory Angle not Jiving w/Sharpie? 7 months 3 weeks ago #15335

  • JDS
  • JDS's Avatar
  • OFFLINE
  • Senior Boarder
  • Posts: 49
  • Karma: 1
Pic #2

IMG_0133ReSize300.png
The administrator has disabled public write access.
Time to create page: 0.151 seconds