If you're not interested in the debate don't open your mouth with inane nonsense. It's a discussion. I will buy one, but I won't concede that the angle doesn't change, because that's completely ridiculous.
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Angles on fixed-angle sharpening systems
- Thread starter ibrow
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If you're not interested in the debate don't open your mouth with inane nonsense. It's a discussion. I will buy one, but I won't concede that the angle doesn't change, because that's completely ridiculous.
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It's no different than the Wicked Edge setup... so, not sure why you think it is?
Again, you're looking at the wrong angle (or the wrong dimension?). The angle between the blade edge and the stone is the angle when you sight down the blade edge... in the KME picture it's the picture on the right. Just like the W.E. picture... you sight down the edge to see the angle. a,b, and c all stay the same distance as you move down the edge... they never change... so the angle of the stone to the edge also never changes.
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Here's one last picture... going back to the W.E. setup... the angle was set at 20°, and I then put a stone on the rod, and stretched it out as far as I could, and measured the angle, which showed 19.6°.
Now, if you looked down on the W.E. (the top photo from my earlier post), you would see a difference of several degrees... agree? .4° is just the error in the setup... certainly not the angle difference you would see in what's probably over a foot of difference.
That's all I got.
Now, if you looked down on the W.E. (the top photo from my earlier post), you would see a difference of several degrees... agree? .4° is just the error in the setup... certainly not the angle difference you would see in what's probably over a foot of difference.
That's all I got.
Are you trolling me? Measure the yellow lines. They change. Dude, if the yellow lines on the KME setup are of different lengths and it's painfully obvious they are, then the angle between the yellow line and the ruler must change. I honestly don't know what other angle you're talking about.
And I never said it's different than the Wicked Edge. It's easier to translate to the diagram tho.
And I never said it's different than the Wicked Edge. It's easier to translate to the diagram tho.
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No... I'm trying to explain to you, that length does not matter. You are looking at the wrong triangle.
Edit to add (since you did):
I think that's the situation here. Until you "see" (either from the earlier pictures or by setting it up yourself, like I did) the actual triangle created between the stone and the blade edge, again by sighting down the edge, you're not going to see why the angle stays the same. The "yellow lines" on the KME are no different than the lines created on the W.E. setup (which are even more obviously longer)... and like I said earlier, in over a foot of difference, you can see there would be a huge angle change if I was measureing the angle you're looking at.
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I think you don't want to admit you're wrong. What other triangle? Yellow line is hypotenuse, or rod with stone. If its length changes, and you admit it does, then the angle between the line and the ruler (or blade) MUST change. That's a mathematical truism. That's the triangle, the yellow line, the line to the base and the height from the base to the pivot. Are you obfuscating this on purpose at this point?
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The triangle created as you sight down the edge. Can you not see the difference in the photos? Sight along the edge...not looking down.
The roof analogy is wrong. This is why analogies are flawed. The roof analogy would be right if you drew a line perpendicular to the ridge from the top of the roof. That's the middle yellow line on the KME picture above.
Now you have to draw a line again from the top, from the point where this first line originated, and draw it to either side of the first line, until it reaches the ridge. It's obvious this line is longer than the first.
Because it's longer, the angle between it and the ceiling of the house (the flat plane under the roof that covers the the top of the walls) is smaller (and that plane corresponds to the plane of the clamp or the knife itself.
That 3D model I posted is as clear as it gets. How can you argue against it?! Introducing roof analogies when you have a 3D coordinate system in front of your eyes. You see where it says 30 something degrees? You see where it says 50 something degrees? The angles are clearly marked. Those are the angles you're using when sharpening on these systems.
The angle would remain the same only if the blade of the knife followed the radius of the cone in that diagram.
Now you have to draw a line again from the top, from the point where this first line originated, and draw it to either side of the first line, until it reaches the ridge. It's obvious this line is longer than the first.
Because it's longer, the angle between it and the ceiling of the house (the flat plane under the roof that covers the the top of the walls) is smaller (and that plane corresponds to the plane of the clamp or the knife itself.
That 3D model I posted is as clear as it gets. How can you argue against it?! Introducing roof analogies when you have a 3D coordinate system in front of your eyes. You see where it says 30 something degrees? You see where it says 50 something degrees? The angles are clearly marked. Those are the angles you're using when sharpening on these systems.
The angle would remain the same only if the blade of the knife followed the radius of the cone in that diagram.
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I think at this point, you'll have to do what I did... because I didn't believe it either. That's why I mounted such a long piece of metal in the W.E., 'cause I figured it would be obvious that the angle would change over such a distance (around 30"). Only when I did this, did I figure out the actual angle relationship between the stone and the edge.
That wouldn't be an analogy... that would be an actual setup.
Hope this has helped!
Imagine the blade extends to infinity. The rod and the stone would have to extend so far to get to the edge at a very long distance from the clamp, that they would be almost parallel to the edge. The angle would be tiny.
Your setup can suffer from many flaws (I don't even have faith you understand what triangle we're talking about), mathematics can't. When I get one of the systems and an angle cube, I'll make a video demonstrating this.
Your setup can suffer from many flaws (I don't even have faith you understand what triangle we're talking about), mathematics can't. When I get one of the systems and an angle cube, I'll make a video demonstrating this.
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This is like going to a staff meeting at the Dept. of Redundancy Dept.
(I've been to a few.)
We'll give this a little longer to see if it runs out of steam. Otherwise we'll just have to agree to disagree...sort of like with religion, politics, and Ginger or Mary Ann.
"You want us to choose?"
(I've been to a few.)
We'll give this a little longer to see if it runs out of steam. Otherwise we'll just have to agree to disagree...sort of like with religion, politics, and Ginger or Mary Ann.
"You want us to choose?"
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Along a straight edge that is perpendicular to the stone rod at 90 degrees, the angle holds constant.
If you clamp the edge the same distance from the tip it will reliably reproduce the same angle around the belly.
The angle only changes as you remove steel, becoming slightly less acute as you work. You would have to minutely lower the stone rod as you work to hold the exact same angle. But that is really picking nits.
There are several ways to test this as proof of concept. Test, observe, conclude. Forming conclusions without this step is not wise.
If you clamp the edge the same distance from the tip it will reliably reproduce the same angle around the belly.
The angle only changes as you remove steel, becoming slightly less acute as you work. You would have to minutely lower the stone rod as you work to hold the exact same angle. But that is really picking nits.
There are several ways to test this as proof of concept. Test, observe, conclude. Forming conclusions without this step is not wise.
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Not to come off like a jerk, but I'm looking forward to that video. Is gonna have a surprise ending.
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Mary Ann..definitely Mary AnnThis is like going to a staff meeting at the Dept. of Redundancy Dept.
(I've been to a few.)
We'll give this a little longer to see if it runs out of steam. Otherwise we'll just have to agree to disagree...sort of like with religion, politics, and Ginger or Mary Ann.
"You want us to choose?"
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Ginger!
Yea. The difference between politics/religion and math is that the latter doesn't allow for differing opinions.
I have yet to see anyone explain why the angles in that diagram are different lol. You can use the exact same program online and graph it yourself.
You know why scientific findings are true? It's not because there's divine Truth, absolute truth. It's because they allow you to make correct predictions. When I get the rig, I'll measure the lengths and plug them in the formula and predict the angle. Then I'll measure. Depending on the accuracy and precision of the angle measuring instrument, it will correspond to the calculated angle.
No one has given a reason why angles would stay the same. No one has explained why the angles in that coordinate system are different. I didn't make them up. The computer did the number crunching.
I have yet to see anyone explain why the angles in that diagram are different lol. You can use the exact same program online and graph it yourself.
You know why scientific findings are true? It's not because there's divine Truth, absolute truth. It's because they allow you to make correct predictions. When I get the rig, I'll measure the lengths and plug them in the formula and predict the angle. Then I'll measure. Depending on the accuracy and precision of the angle measuring instrument, it will correspond to the calculated angle.
No one has given a reason why angles would stay the same. No one has explained why the angles in that coordinate system are different. I didn't make them up. The computer did the number crunching.
Here's one last picture... going back to the W.E. setup... the angle was set at 20°, and I then put a stone on the rod, and stretched it out as far as I could, and measured the angle, which showed 19.6°.
Now, if you looked down on the W.E. (the top photo from my earlier post), you would see a difference of several degrees... agree? .4° is just the error in the setup... certainly not the angle difference you would see in what's probably over a foot of difference.
That's all I got.
EDIT:
Measure the length of the line in red. You've given the angle (20 degrees) - the angle between the rod with the stone (hypotenuse) and the line that makes up the height from the base to the edge (adjacent). With those two you can calculate everything, and the new angle.
If the red line is, say 10 cm long, then the adjacent* is 27.5 cm and the length of the rod from the pivot to the edge on the portion of the blade in the middle of the clamp is 29.2 cm.
If the length between the edge in the middle of the clamp and the part where the stone touches the edge in the above image is 3 cm (you said a foot, you could measure how long it juts out), then the adjacent increases from 27.5 to 27.66, and the length of the rod from the pivot to the blade at that point increases from 29.2 to 29.41. This reduces the angle from 20 degrees to 19.86 degrees. A deal breaker? Not at all. Does the angle change? Yes.
Assuming a perfectly accurate and precise angle cube, and you giving me the exact measurements, the calculation would match the angle cube.
I got 3 cm as a realistic edge length from the center to the heel from one of my own folders. If you use a big knife where that goes up to 10 cm, the angle would go down to 18.85 degrees at the heel. You'd have a portion of the knife ground at 20 and a portion at less than 19. Is that significant now?
* to further clarify: the adjacent refers to the distance from the base to the edge. Its length changes when you move outwards along the edge, obviously. It is this line that creates the angle with the rod/stone, and it's the line the blade sits on.
I calculated everything using the Pythagorean theorem and then I plugged in the results here: https://keisan.casio.com/exec/system/1223014690
EDIT 2: I just watched the video where the guy retracts his previous video and statements. The slope of the roof is NOT the same if you go down the roof from the top down to the ridge on the shortest path vs on a diagonal. Diagonally you will have a less steep slope, a longer way to go, and ultimately a smaller angle. The roof didn't change though, doesn't mean the slope didn't either. The slope is the hypotenuse, and it has to compensate for the increased length of the adjacent by "tilting up", which makes it less steep.
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Simple experiment. Set up something heavy on a table or near a countertop and tie a string to it. Make the string taught and draw it over the edge of the countertop. View it from the long edge of the countertop with the string at 90° to the edge of the counter. Now while still sighting along the counter top begin to move the string back and forth, keeping it taught. The angle you observe the string forms with the counter does not change.
If you shift your line of sight to the plane of your triangle so it is perpendicular, the angles indeed change considerably, but sighted along the line of the countertop (edge) the angle is unchanged.
A similar principle, set a carpenters angle on a table and view it perpendicular, it is 45°. Now rotate it, the angle appears to become less acute, but in fact it isn't changing, only your viewing angle is changing.
If you shift your line of sight to the plane of your triangle so it is perpendicular, the angles indeed change considerably, but sighted along the line of the countertop (edge) the angle is unchanged.
A similar principle, set a carpenters angle on a table and view it perpendicular, it is 45°. Now rotate it, the angle appears to become less acute, but in fact it isn't changing, only your viewing angle is changing.
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