Emerson Commander
Posted by Bugout Bill
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Re: Emerson Commander August 05, 2016 03:55AM |
Hi Bill. Yes, I did an extensive video, and the simple reality is that anything you percieve as better cutting from a chisel vs a non chisel is geometry related and nothing else. Feelings aside. Take the following example, which has a v-grind, and a chisel grind which are identically equal. one can't be better than the other implicitly.. Why? because its the same triangle that I rotated with an image editor. a 25Degree inclusive chisel is the same as a 25 degree v grind.
the confusion arises when you have a 15DPS v grind and people take a 15degree inclusive chisel as the "equivalent" and say its twice as lean.. this is just fundamentally flawed math as a 15degree inclusive chisel is a 7.5dps v turned on its side. I've also had a similar long debate with a friend knifemaker a long time ago, because when I was saying a full flat zero V-grind of 6dps to a spine thickness of 6mm, in his mind a chisel grind of the same knife was a 3dps knife with a 3mm spine (chop it in 1/2) so its leaner and better. its not apples with apples any more.
Now.. putting that aside.. of course there will be noticable differences in cutting performance in different media because most knives are not triangles, but facets at a minimum on most production a primary and secondary of significant difference in angle with a edge bevel.
the assymetric entry into the cutting material is going to create difference deflections of resistance etc as a chisel will want to push all things to one side and the v-grind wants to spread it evenly.. so if you are shaving slices off the end of a hard tuber a chisel is deflecting everything off the side with least mass, making it feel easier.. a v would resist more pushing 1/2 the energy into the primary mass of the cut material..
if the knives are ground keenly enough, the differences are negligible.
here are the videos. Like anything I do. its not pre-scripted, and I'm speaking in laymen terms.. hence.. verify.. peer review.. dont take anything I say as gospel without testing.
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[data.gearbastion.com]
KnivesAndStuff (YoutTube)
the confusion arises when you have a 15DPS v grind and people take a 15degree inclusive chisel as the "equivalent" and say its twice as lean.. this is just fundamentally flawed math as a 15degree inclusive chisel is a 7.5dps v turned on its side. I've also had a similar long debate with a friend knifemaker a long time ago, because when I was saying a full flat zero V-grind of 6dps to a spine thickness of 6mm, in his mind a chisel grind of the same knife was a 3dps knife with a 3mm spine (chop it in 1/2) so its leaner and better. its not apples with apples any more.
Now.. putting that aside.. of course there will be noticable differences in cutting performance in different media because most knives are not triangles, but facets at a minimum on most production a primary and secondary of significant difference in angle with a edge bevel.
the assymetric entry into the cutting material is going to create difference deflections of resistance etc as a chisel will want to push all things to one side and the v-grind wants to spread it evenly.. so if you are shaving slices off the end of a hard tuber a chisel is deflecting everything off the side with least mass, making it feel easier.. a v would resist more pushing 1/2 the energy into the primary mass of the cut material..
if the knives are ground keenly enough, the differences are negligible.
here are the videos. Like anything I do. its not pre-scripted, and I'm speaking in laymen terms.. hence.. verify.. peer review.. dont take anything I say as gospel without testing.
----------------------------------------------------------------------
[data.gearbastion.com]
KnivesAndStuff (YoutTube)
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