large convex chopper knife profile question

misanthropist

misanthropist

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Jan 28, 2007
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Okay, here is a little question maybe some of the "large knife guys" on here can answer for me.

I have always been an axe guy but would consider branching out, because, after all, why not?

One thing I have been wondering, though. Large convex choppers...what is the profile like?

I looked at my Wetterlings Large Hunter axe, for instance. That has a good, general purpose chopping profile IMO.

Setting my calipers to .250", I can slide them back just over an inch on the bit before they stop. Say maybe an inch and a quarter, or an inch and an eigth.

But big chopping knives are typically made out of 1/4" stock, aren't they? That is probably what I've seen, anyway.

So on the convexed ones - like say the Gossman knives, which I really like, how far back on the blade before the profile is pretty much the full thickness of the stock? I would guess the really big blades Scott makes are close to two inches wide, and I believe they are full-height convexed. But is the last inch the majority of the angle?

Or is my axe a steeper grind than it needs to be, or than a chopping knife would be?

Thanks guys!
 
To much depends on what you are going to chop. A good chopper does not have to be thick. The Humble 12 inch tram chops many materials very well and is nowhere near 1/4 inch thick. Koyotes knives for the most part are pretty thin for what many consider choppers but believe me, they will chop. Lighter and thinner give you more speed and the thick ones of course give you more weight. I prefer thin and wide but then I prefer a hatchet or ax for any heavy chopping.
 
I hear you there for sure, but what if for the moment we assume it's a thick knife? How steep is that convex?
 
Well I guess I can give you my take. To me a thick knife is 3/16 and thicker. I don't know quite how to answer the convex part of your question but to me It has to depend on the thickness of the blade. Knives with a pretty flat grind then convexed just enough that the edge is not as apt to roll over, makes sense to me. Thick blades fully convexed chop well but to me are not great slicers or as versatile. I will be interested in hearing what others who know more about the convex have to say. I can't always explain what I mean:confused:
 
from what i have seen (based on memory, i don't have one in front of me) Scott's curve starts at the spine and is fairly flat until it hits the edge bevel.

so it is alot like a full flat ground knife, but with a little more meat in the blade.

in my experience, many chopping knives tend to have thinner edges than most axes. one reason that i have been working on getting my axes to thinner edges...it is alot of metal to remove though.
 
Hmm, good info there, guys, thanks. Maybe I should ask Scott himself... I suspect he knows what grinds he lays on his knives!

Hey Horn Dog, I see you reading this thread and you own a lot of big choppers!

What's your take?
 
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When I’m grinding a full height convex chopper designed for hardwood I do most of the work on a slack belt and leave plenty of material behind the edge; more axe like.

When doing a full height convex designed as a slicer I do more work on the platted, before switching to the slack belt; leaving a thinner edge geometry.



"If you're not living on the edge, …you're taking up too much space."

Big Mike
 
I just checked my best chopper (Busse Battle Mistress; convex, 1/4" stock). The initial bevel comes up 1/8" from the edge, then the somewhat steep "secondary bevel" comes up another 1/2", then the main bevel comes up another inch.

So the whole thing goes from edge to full thickness in about 1-1/2". It's not that much more gradual than your Wetterling....

Hope that helps you,
desmobob
 
That's also very helpful...I had no idea Busse knives were convex, either. That's funny, because I am in the early stages of building a knife in part because I wanted something like a Battle Mistress, but convex. I have been working a little bit on what I considered to be a "Tusker Mistress."

But I guess I am behind the curve as I thought they were a sabre grind for some reason.

Anyway that's very helpful, desmobob, thanks very much.
 
misanthropist said:
That's also very helpful...I had no idea Busse knives were convex, either. That's funny, because I am in the early stages of building a knife in part because I wanted something like a Battle Mistress, but convex. I have been working a little bit on what I considered to be a "Tusker Mistress."

But I guess I am behind the curve as I thought they were a sabre grind for some reason.

Anyway that's very helpful, desmobob, thanks very much.
Click to expand...

My Battle Mistress was not convex but was added later. I'm not sure if many or any Busses come convexed.
 
misanthropist said:
That's also very helpful...I had no idea Busse knives were convex, either. That's funny, because I am in the early stages of building a knife in part because I wanted something like a Battle Mistress, but convex. I have been working a little bit on what I considered to be a "Tusker Mistress."

But I guess I am behind the curve as I thought they were a sabre grind for some reason.

Anyway that's very helpful, desmobob, thanks very much.
Click to expand...

You're welcome!

The CGFBM (Combat Grade Fusion Battle Mistress) is slightly, "semi" convex. :)

That short initial 1/2" bevel after the actual edge bevel is flat. The next inch has a shallow convex profile and the final full-thickness part of the blade next to the spine is flat. So, it's flat-convex-flat. I used a metal rule to check it... I'm not guessing. My Busse Skinny ASH is fully convex, while the standard ASH1 is fully flat ground. Busse uses a little of everything!

Stay sharp,
desmobob
 
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