Sigh…
- This topic has 25 replies, 11 voices, and was last updated 07/31/2017 at 10:02 am by
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Snecx- that video is pretty brilliant. Unfortunately, the guy still thinks that the plane represented by the sheet of glass is imaginary and that the stone travels on some other plane…
NO kidding! I think the challenge is more difficult than we’ve all expected. I hope you’ll be able to bust this myth once and for all. Good luck!
Hey guys,
Here’s this response from Jeremy that authored the video:
Hello Clay,
I now know that I am wrong in that video. I was looking for answers and I finally had someone explain it to me in a simple manner.
I am going to release a new video, probably Wednesday or Thursday, explaining this and I will also probably sharpen a straight piece of steel to show that the edge bevel remains the same. It’s crazy how something so simple could be so over-thought. I was applying a three dimensional example to a two dimensional reality. I get where I was off now.
The good thing is; that video got a lot of comments and interaction. I think when I release the follow up, there will be a lot of people that were convinced I was correct, seeing where we were wrong. I’m wondering if I should leave that video until Friday or Saturday even, as viewership is much higher on those days.
I sure appreciate you reaching out and helping me clear this up. I’ll also re-title the video the (non) Truth about knife sharpeners, after the other one comes out.
Cheers,
Jeremy
So, that’s a good win. I’m glad Curtis saw it and thanks Snecx for your awesome video. I think I’ll try to recreate it and add some animations in to show it off. For now, do you mind if I add your video to the Knowledge Base about the subject?
-Clay
Nice work Clay and others! The facts have won the battle!
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Wow! Excellent work, gentlemen. That is really great – and it sounds like not only did the YouTube Expert change his mind – no small feat – but that he will also do the right thing, and inform his viewership of all this.
As somebody with advanced terminal cancer, there will be dark days when I complain about things you say for no apparent reason. Please consider this my apology in advance for such times. There will be days that what I say is clearly wrong, making no sense: on these days I will often be argumentative. Please do not "let me slide" at such times, but rather call me out, point out what is factually wrong, and demand I explain my position. Please also consider this my apology in advance for such times.
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That’s awesome! Hard to find people who are humble and accept they are wrong these days hehe, kudos to him!
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So, that’s a good win. I’m glad Curtis saw it and thanks Snecx for your awesome video. I think I’ll try to recreate it and add some animations in to show it off. For now, do you mind if I add your video to the Knowledge Base about the subject?
Feel free to put it on the Knowledge Base. I’m glad the video can be of good use for now.
And it’s great to hear about the outcome. Definitely a win for everybody!
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It looks like he posted the correction… (Wonder where the “dental floss” idea came from)…..
And I am forever in your debt for setting me right to the world, cbwx34… Gotta hand it to this guy for accepting that he was proven wrong.
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The three best analogies I read in all the comments to his videos are:
- Windshield wiper – assuming the windshield is flat
- Pitched Roof – standing on the apex with a long board nailed to a pivot
- A pyramid – Attaching a pivot at the very top
Bob Nash at Oldawan also made these two comments which were excellent because they bring up some other very interesting points:
By your logic a carpenter building a pitched roof would have to change the angle of each truss where it meets the outside wall as they got farther from the center of the building. The rod holding the stone is simply moving along the plane of the roof as you move it left to right and the angle where it meets the O1 is not changing – just like on a roof where the roof plane meets the outside wall. Your drawing is leading you astray because it mixes up two different views of the triangles in question. First view is the narrower triangle formed by looking down the O1 stock from the end – the tip or the handle of the knife. The second view creating the second triangle with the longer sides is looking at that second triangle also from it side. But that side view is found by looking over the top of the O1 stock from in front of the sharpener somewhere, not down the length of the O1 stock. If you turn the sharpener and look down the O1 from one end or the other while moving the stone along the piece of steel you’ll see the stone is always moving in the same plane so making the same angle while contacting the piece of steel. Moving that to your drawing, if you stay in the same view of the triangles, the second larger triangle is actually completely hidden behind the first. You could also see this by laying a board or a piece of cardboard across the steel you are using to simulate a straight cutting edge and lifting it to the angle position you want to sharpen at on the upright. The board or cardboard always makes the same angle as it meets the steel along its full length.andJust to clarify a bit. I’m not saying that the 2 triangles in the drawing aren’t actual triangles relating to the cutting edge. Both do show something about the angle at the cutting edge. It is just that the sharpening angle is always measured at 90 degrees to the cutting edge, just like the angle of a truss. The second larger triangle is measuring the skew angle of some cut you might be making. The angle you are looking at in your second larger triangle is the effective cutting angle if you are pushing the knife forward and down in the direction the rod is pointing through whatever you are cutting. The effective cutting angle is measured directly in line with the cut direction. This effective cutting angle is lower than the actual sharpening angle in this case. That cutting angle is always lower to or equal to the sharpening angle depending on the direction of your cut. The more forward (or backward) motion you have relative to downward motion the lower your effective cutting angle. If you work with hand planes or chisels you are probably used to skew angles. You sharpen the blade at a set angle and if you cut with the plane oriented so that the cutting edge is 90 degrees to the cut then the cutting angle is a combination of that angle and the bed angle in the case of the plane – or just the sharpened angle in the case of the chisel. You might have trouble cutting pushing straight into the fibers of the wood. If that is the case then if you twist the plane or chisel slightly so that the cutting edge is not at 90 degrees to your cut, the cut will be much easier. That is because in relation to the wood you have effectively lowered the cutting angle. The wood fibers move over more of the bevel than they would have if you were cutting straight into the wood. You are also of course slicing instead of push cutting the fibers which helps too. This is the same of course for a knife on a tomato. Leonard Lee probably has the best explanation (and diagrams) of this I’ve ever read in the first chapter of his book on sharpening.-Clay
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