Forward angle and chopping

[killa_concept]

I slashed some water bottles last night. The M43 didn't hardly get me wet and the 20oz bottle was clean in half. The 20" AK did something weird. I probably didn't hit square or I hit with the tip and drug it. Think Spiral cut ham. That is 1 cut as fast as I can control it I couldn't do that with my pocket knife if I tried.

Was that prior to sharpening though? I put a shaving edge on that m43 before sending it back to Aunty so it still probably had it when it got to you. Products directly from HI tend to be just "functionally sharp" which is to say that they'd work fine for chopping

 

[oldschool45]

killa, I sharpened it before I went chopping because the edge on the 20" AK was rolled ever so slightly when I got it. I worked it out to about 1500 grit but there is still a dull area on the tip and in the center of the sweet spot. They'll go away in a few more sharpenings so I won't kill my self getting them out just yet. It absolutely amazes me that I can chop like hell on these things for over an hour and they will still shave

 

[oldschool45]

That's it I'm done with the premeditated attacks on defenseless water bottles with the 20"AK. I had just honed it to shaving sharp before the most recent assault
The M43 is now the designated hitter.

 

[warty]

I have never chopped with my Boomerang. I bought it in pristine condition and I already have so many choppers that I just decided to keep this one nice. This is made by Sher and has a relatively beefy spine like all of his work. I'm not sure how it would chop really, it is very tip heavy but at the same time feels a little awkward in the hand. Not certain how it would work out if I was giving it a decent swing...

(scale is inches)​

 

[Howard Wallace]

It takes a lot of insight to even ask this question.

Part of the answer will depend on the weight of the blade and the chopping methods employed. For a light blade that will be used with considerable wrist snap the angle need be less. The less flexion of the wrist durring the chop the greater the optimal angle of the blade. Heavier blades usually are used with less wrist flexion and may accomodate a greater blade angle. A heavy khukuri with a pronounced bend can be held with a neutral wrist position and still chop effectively. A modern ergonomist would understand perfectly the logic of the ancient design.

Another factor influencing the bend angle is whether the material being cut needs to be pulled towards the handle. This may not be a factor in cutting firewood, but in cutting vines or even for weaponry usages the ability to pull the object being cut towards more cutting edge rather than push it off the end of the knife can be important.

Namaste,

 

[killa_concept]

I have never chopped with my Boomerang. I bought it in pristine condition and I already have so many choppers that I just decided to keep this one nice. This is made by Sher and has a relatively beefy spine like all of his work. I'm not sure how it would chop really, it is very tip heavy but at the same time feels a little awkward in the hand. Not certain how it would work out if I was giving it a decent swing...

Yeah - I would want to keep that one pristine as well. Sher is no longer with HI and some of his more intricate designs (such as that one) were simply phenomenal. Your personal handling knowledge says a lot though... perhaps that level of forward curvature would be handy for slicing through springier, smaller vegetation but I can see how that would make chopping a bit more awkward.

It takes a lot of insight to even ask this question.

Part of the answer will depend on the weight of the blade and the chopping methods employed. For a light blade that will be used with considerable wrist snap the angle need be less. The less flexion of the wrist durring the chop the greater the optimal angle of the blade. Heavier blades usually are used with less wrist flexion and may accomodate a greater blade angle. A heavy khukuri with a pronounced bend can be held with a neutral wrist position and still chop effectively. A modern ergonomist would understand perfectly the logic of the ancient design.

Another factor influencing the bend angle is whether the material being cut needs to be pulled towards the handle. This may not be a factor in cutting firewood, but in cutting vines or even for weaponry usages the ability to pull the object being cut towards more cutting edge rather than push it off the end of the knife can be important.

Namaste,

And it takes significantly more insight to answer it so thoroughly and articulately. Many thanks Howard! I guess this is why we see most kukris with a roughly ~30-35 bend with 45 degrees being about max. Past that and it becomes too scythe like - trading chopping power for more of a sheering effect.