Thread: wider bevel=more flex?

Originally Posted by Quick

Wow! I wasn't aware of that. You mean that the blade is actually thinner at the full hollow point than at the edge?

No, the drawing was made too hastily to be accurate in that respect.

I am starting to be confused. Are you still disputing my simple observation that a wedge is beefier, also at the cutting bevel?

Imagine that we would hone a wedge, and next regrind it to a full hollow, without damaging the very edge. It can't be that hard to see how the lower part of the original bevel would be ground away too leaving less wide bevel panes.

No?

No.

Just for example.
Lets say you start at the very edge and start heading for the spine. Lets say that the bevel width (flat side of the bevel measured from the very edge towards the spine) is 1 mm. In your first example you use the term "height". I'm assumed this was the same measurement you were refering to?
Let's say that the bevel angle is 20*

2. the thickness of the blade.
A full hollow has a very thin blade, hence a small bevel is to be expected. A wedge has a thick blade, hence it will carry wider bevel sides. In this case the wider bevel will be a bit sturdier, because it contains more steel for the same height. (it has a wider base).

If you measure at the same bevel "height"
and you compare equal bevel angles. Then the bevel itself has to contain the same amount of steel.

I think I understand what you were saying but I think you may have mixed two thoughts.

1) In general, wedges will have wider bevels due to less hollow in the blade. Wider bevels will contain more steel simply due to triangle geometry. (but at the same time they would have more height to the side of the bevel).

Or

2) Were you saying that, generally, wedges have a wider spine and therefore more bevel angle. So measured at the same height up the side of the bevel they would contain more steel. (different bevel angles)


Haha, it would take about 10 seconds to resolve this if we had a white board. It would take me hours if not days to produce illustrations like yours.

Originally Posted by Quick

Haha, it would take about 10 seconds to resolve this if we had a white board.

So true.

I have been thinking we kinda agree from the start, only use different words for different terms.

Let's rule out the spine thickness. In my first point (that states that bevel planes grow wider with diminishing bevel angle), the grind must be constant, but the spine must vary.
In my second point (the one we seemingly disagree upon) I start from a constant spine thickness.

So, with constant spine thickness, let's assume we are going to cut a strip of 5 mm of two razors, parallel to the very edge. Hence the strip will hold the edge and then some.
Now let's compare those strips:
The first strip comes from a wedge. The bevel sides will occupy a big part of our strip, if not all the strip.

The second strip comes from a full hollow. The bevel sides will occupy only a narrow part of out strip.

The bevel angle on both strips would be equal. But the bevel can't run as far down on the second strip, because their is no steal where it can run into. That steel was ground away by the person that made the razor.

Bart.

Yep. 100% with you there. It was the "height" thing that I don't think should have been there.

In this case the wider bevel will be a bit sturdier, because it contains more steel for the same height. (it has a wider base).

See, I read that as "height of the bevel". Now I'm thinking you meant height of the bevel for the wedge case and at that same height (which would extend above the bevel in the hollow case). I was pretty sure I understood what you were saying but like I said, I thought maybe you didn't type it quite right?

Originally Posted by Quick

Wow! I wasn't aware of that. You mean that the blade is actually thinner at the full hollow point than at the edge?

Yup if it's really hollow, you can see a "belly" down near the cutting edge where the balde gets fat again before narrowing down to the final cutting edge.

Originally Posted by Quick

Yep. 100% with you there. It was the "height" thing that I don't think should have been there.



See, I read that as "height of the bevel". Now I'm thinking you meant height of the bevel for the wedge case and at that same height (which would extend above the bevel in the hollow case). I was pretty sure I understood what you were saying but like I said, I thought maybe you didn't type it quite right?

Well yes, we speak a form of local Dutch back home in Belgium, but most Dutch members wouldn't understand half of it.
So excuse my poor English. I use many expensive words to make it sound intelligent, but the truth is that it is sometimes very hard to express my thought with any precision.
I clearly meant an imaginary strip of steel of equal width on both razors, when I wrote "same height". It's not the first time someone needs to step in and clarify my thoughts...
Thanks for that,

Bart.