- Joined
- Mar 8, 2008
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Right here:
"highest" would make no sense here for a V edge, because with a V edge there is only ONE spine height over the stone: There is no "highest"... So you are talking here strictly about a convex edge, and you are saying everything beyond the initial apex edge angle ("highest spine height") is "relief"...
It isn't: The "relief" is most critical near the apex: It becomes increasingly less important after that... In splitting some materials the convex may have less drag, but some other materials will also offer less drag to V-edge shoulders... Drag is not an advantage a convex edge can claim consistently, because cutting is mostly not about fluids... So the only convex "advantage" left is a stronger more open apex angle for a given profile thickness...
What most convex edge fans say is that the convex edge has 1-more apex strength/durability and then 2-less subsequent drag...
What they get wrong is that you need to reverse that order: You need 1-less drag and then from that follows 2- More edge strength/durability.
The reason they get the order wrong is they mistakenly assume more "strength" in front will buy them less drag.
The actual reality, as tested, is that sharper (up to a point) apex angles have a sharpness that is more durable, as if the steel was better, because sharper apexes transfer side loads more readily to their stronger parts, which also reduces drag.
You have to start with the "relief": So there is no "relief" after that...
Gaston
You dramatically misconstrue my statement...
When forming a convex edge against a flat stone, you start the angle you want the edge to be, and drop the angle as you progress over the stroke, which lifts the apex off the stone and abrades the shoulders, blending the shoulders into whatever grind (if any) is behind the edge. The apex is only being abraded at the greatest angle out of that range during the stroke, and as such it is that which is the edge angle. Everything behind that angle is a relief in the geometry because of its lessened angle. You claimed:
[emphasis added]You think that for any given apex strength you gain easier penetration with convexing.
I did not say that. I've discussed only geometry, not strength.