Choppers, Weight vs Design

V

VCB

Joined
Sep 13, 2005
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I have an Ed Martin WSK with a 6 1/2" blade that has an axe shape to it, that chops better than a bowie/camp knife with a 7 1/2 blade. The little axe curve and point on the WSK gives better penetration on the chop, but the WSK is also heavier, and weight forward. I see guys write about Kukris chopping better than bowies, but again the kukris look heavier than the bowies. So what figures into chopping more blade weight or blade design? Would a 1 1/2 lb bowie chop just as well as a 1 1/2 lb kukri? vcb
 
It's not just weight! That plays a role, but more important factors include where that weight is on the blade (the more forward it is the harder it'll hit for the weight) and also the thickness. A thin broad blade will out-chop a knife of equal mass/x-axis weight distribution because it has more mass behind the edge rather than to the sides.

Since a knife/chopper isn't like a saw (no kerf of material being removed) the edge must displace the material at the point of impact. A thin blade will not have to push as much material to the sides as it passes through a targer, while a thicker blade (again, of equal x-axis mass distribution) will lose more energy since it has to push the same material further in order to travel the same distance.
 
So what you're saying is the best possible chopper will have a broad, thin blade with a lot of weight at the end? I'm curious because I'm in the market for a chopper too, and I want to know what to look for.
 
I think 42 means something like this lol:
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A lot depends on e blade geometry and the grind.

Full flat convexed grind will have less places for it to bite into wood, or what ever it is you are chopping. As mentioned the weight distribution of a knife also effects its chopping abilities. Look at the competition blades to get better idea, what industry considers to be ideal chopping blades.
 
I have had extensive experience with my M-43 kukri as well as others.

If you were to go on the H.I. website they have a FAQ on the difference in the drop of the blade on different kukri patterns. The M-43 has one of the deepest drops of the tip plus the handle drops as well. It is also lighter than the Ang Kholas and has a thinner edge. It consistently out chops everything I've run across including many axes.

The reason for this is in the design of the M-43. The deeper drop to the blade tip places the weight forward, lengthening the sweet spot and applyin more power to the cut. The drop of the handle as well makes ti so that upon the last stage of the swing the tip speed is accelerated. This combined with a thinner edge results in greater penetration into the work. The M-43 is designed to take advantage of the laws of physics.

Weight alone will not result in a better chopper. It has to be combined with blade design, edge geometry and handle design to make a knife with above average chopping ability. Otherwise you just wind up with a boat anchor that wears one out when working with it.

The M-43 due to it's design has an exceptionaly lively feel to it unlike any other kukri I've owned. If you like chopping you owe it to yourself to try one out.
 
A lot depends on Blade Grind also.

Just making a 32 ounce knife doesn't mean it will work.

But yes my Busse NMFBM will out chop a Khurki and do it easy from my experience, but that is about the only one other than the FFBM that is about equal.
 
I think that, shy of an actual quality hatchet, the traditional parang candung/bandol/lading styles of blade give the most chop per ounce... not that they'll outchop other less streamlined designs with more mass, but that if the maker is limited to a given weight of steel, that these designs will likely outperform others with the material available.
 
Iboschi said:
I think 42 means something like this lol:
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Click to expand...

Haha! Sort of. In theory the blade that would chop deepest out of any design would be infinitely long, infinitely thin, and infinitely heavy, yet with all of the mass at the very tip of the blade. It would also be infinitely useless due to being infinitely unwieldy. :D

Chopping ability must compete against ease of handling, and the two are often polar opposites. It's all about finding the right balance between the two that will make for a piece that both chops and handles well. ;)

That's all a gross oversimplification, but I think it illustrates the principle well. :p
 
FortyTwoBlades said:
Haha! Sort of. In theory the blade that would chop deepest out of any design would be infinitely long, infinitely thin, and infinitely heavy, yet with all of the mass at the very tip of the blade. It would also be infinitely useless due to being infinitely unwieldy. :D
Click to expand...


I want one!!!
 
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