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I really liked this YouTube video which has a field engineer explaining many electron microscope pictures of new and used grinding wheels. I was surprised at how stringy swarf is from the abrasion process. Narrator said the high speed steel was approximately 60 HRC.

https://youtu.be/SD1BJG-XcuQ ...

I wonder how much of an angle change needs to be achieved from one end of the stone to the other to create a convex bevel that is meaningful.

I'm curious about this too! I'm wondering if owners of convex edges would be willing to make a "cast" of their knife edge. You could make a cast by first ...

may be off topic, but have you used guided rod system like edge pro to sharpen a convex bevel? It should be possible if I intentionally make the stone uneven with one side (length wise) a lot thinner than the other side so the angle at which it contacts the edge changes as I hone the edge.

haven ...

Hi Everyone,

I'm interested in how to precisely capture the silhouette shape of a knife. After the shape has been captured, then we could use software to determine the best way to clamp a knife to get the most even sharpening angles/bevels. (For example, we could use the graphs and visualizations I ...

Here is a new version. This will be the last version for quite awhile, I think.

Changes:
Expanded some of the discussion about gimbals, universal joints, and spherical joints in Chapter 3.
Re-compressed the animated contour plots with better (?) anti-aliasing settings.
Minor formatting improvements ...

Here is the latest version. The contour plot visualizations were added to the report in an appendix.

Geometry and Kinematics of Guided-Rod Sharpeners
Version 1.0beta17

Download Link:
https://drive.google.com/file/d/0B8rQYhU8N9ZGSENqc2Q2MlRFbTA/

Alternate Download Link:
http://www.mediafire.com ...

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Chefs Knife
Coordinates are in inches.
Target sharpening angle = 15 degrees per side at the calibration point.
Contour lines every 0.1 degrees per side.
Sharpener is a WEPS-Gen2

Download:
https://drive.google.com/file/d ...

I'm back from the holidays and had a chance to do some visualizations.

So, let me mention what kind of data we're trying to visualize:

Suppose we have a Chef's knife that we want to sharpen on a WEPS-Gen2. Where should we clamp the knife to minimize the variation in sharpening angle?

What we ...

New version of the technical report (1.0beta14) can be downloaded here:

Download Link:
https://docs.google.com/file/d/0B8rQYhU8N9ZGX0stZHg2X3dOaEk/

Alternate Download Link:
http://www.mediafire.com/download/gu9azudyl33amrl/Geometry%20and%20Sharpening%20(DRAFT%201.0beta14).zip

Latest Changes ...

If you are having problems downloading:

Alternate Download Link:
http://www.mediafire.com/download/gu9az ... eta14).zip

Download Link:
https://docs.google.com/file/d/0B8rQYhU ... g2X3dOaEk/

Following a suggestion, I have added three knives to the report: An 8" chef's knife, a 10" khukuri, and the Spyderco LionSpy pocket knife. In the report is a new section,"Case Studies of Curved Blades on the WEPS-Gen1, WEPS-Gen2, and EP-Apex."

You can download the new version of the report here ...

Hi Jack,

Thanks for having a look at the report. Sorry if it's a bit complicated, but I'm glad the videos helped and that you found some parts of it to be useful. :)

The report may be more interesting than it is useful. The slight variances in angle that are due to a perfect mechanism are ...

I will look at it tomorrow morning. I'm on my tablet now and can't look at it. Looking forward to it.

Jack

Edit
It's very possible I won't understand the report if it deals with geometry at a higher level than 10th grade. :) I think that's the last time I had geometry. If I took a class later it ...

In some more detail:

In the report, there is an entire chapter on dihedral angles. They are defined in Chapter 2, and some of the ways they can be changed are also described.

Many different effects are occuring simultaneously, including:
(1) Position of the contact point between the stone and ...

@jackknifeh,

The answer to your questions are in the report. :)

@jackknifeh,

Can I nudge you to read the report? It's written for you and the knife community.
You'll really enjoy it; most of you intuition is on the right track. But I think you are missing a few pieces of the puzzle.

A picture is worth a thousand words, and a video is worth a hundred pictures ...

@jackknifeh,
Thanks. Glad you liked the sharpening rig I made.
I like your idea of Edge Guide Blocks (EGB). I may have to make some. :)

@Evil D,
Oh, I mean that the shape of the knife, like how much belly the blade has, etc. will cause the sharpening angle to vary in the Edge Pro system (in much ...

@Evil D
I agree; if you don't move the blade in the EP, then the skill required is much less. Also, yeah, clamping properly on the WEPS takes a little time. Personally, I don't mind that. btw, if you do not move the blade in the Edge Pro, then it has many of the same effects where the sharpening ...

Hi Brock O Lee,

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The Edge Pro and the Wicked Edge systems are very good. Both are accurate and consistent. It is difficult for me to say which is more accurate/consistent during actual use, because, in practice, their ...

I was asked to do an analysis of sharpening a khukuri knife at 10 degrees per side. The analysis here is for a WEPS-Gen1

I started with photo of a khukuri that I found from http://www.KnifeCenter.com . I then did a polygonal trace of the knife edge which was then spline interpolated with sample ...