What makes for a really good chopper?

chiral.grolim said:
:thumbup::thumbup::thumbup:I was just about to compose a message detailing the same thing! Penetration depth when chopping can be a severe hindrance to efficiency.
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I wonder if a well-proportioned fuller/ air gap allows expansion between the wedge of chop for easy release.
Having cut some really goey vines and seasoned wood it really made a difference. One of the examples would be a Bonecutter khukuri i got from Himalayan Imports; the hollow forged surface allows quick release of the deep bite.
 
JayGoliath said:
I wonder if a well-proportioned fuller/ air gap allows expansion between the wedge of chop for easy release.
Having cut some really goey vines and seasoned wood it really made a difference. One of the examples would be a Bonecutter khukuri i got from Himalayan Imports; the hollow forged surface allows quick release of the deep bite.
Click to expand...

On vines and seasoned hardwood, my HI Khukuri does not penetrate deep enough for the fuller to make any such difference, and the same goes for my hatchets of similar geometry. The vines are <2" diameter and are spread apart apart by the THICK edge-bevel, and the wood also resists penetration beyond that bevel and will chip out if the edge ever makes it that far. Never does the medium being cut reach the point where it would make contact with material left in where the fuller (or back/primary bevel) is ground. Cutting cardboard would present such a contact, but again the EDGE bevel is so thick, that nearly all resistance (and there is a LOT of resistance) to the cut is focused there.

On punky wood, the thick edge is able to penetrate beyond the edge, and THEN the back bevel allows the edge to penetrate deeper because it places less pressure against the surrounding material (i.e. reduced friction), but that pressure is still MUCH higher than is induced by a 0.1" thick stock machete. No, as far as I can tell, the fuller or thin primary grind on these tools is for better penetration and weight distribution while not compromising the integrity of the edge against impacts and its ability to chunk out bits of material.

On vines, the thin machete penetrates deep enough quickly enough that the vine is severed before much friction resistance can be mounted. But on seasoned wood, the thin machete bites VERY deep and STOPS. The machete is so thin, that the wood can press in on the sides and would fill any fuller presented, making extraction MORE difficult.

Perhaps FortyTwoBlades can share some of his withdrawl techniques. A couple tips that I would offer include:
a) make the chop at an angle
- this allows the wood to split somewhat along the grain and move out of the way, reducing the pressure it can exert on the blade
- it also presents more media to the edge, reducing depth of penetration but also presenting less of the primary bevel for the wood/medium to grab hold of
b) chop into a fixed target (one you don't have to hold down yourself) with part of the edge that is sufficient distance from the handle to allow significant leverage to be applied when working the blade out of the cut
c) After the cut is complete, apply sharp/quick pressure on the handle to break the static friction, FIRST downward to bring the tip of the blade up, THEN upward - this extends the pivot point from the handle, allowing increased leverage to break the friction-hold.

Other thoughts?
 
FortyTwoBlades said:
He said geometry, but yeah technique is important as well! I suppose that in terms of the question it comes down to the old debate of dishwasher vs. sanitizer if you know what I mean. YOU are the chopper, wielding a chopping tool--or the chopping tool is the chopper. Definitions definitions... :D
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Technique is important, but as you yourself have clearly demonstrated the environment can dictate what technique or lack thereof is employed.

An awkward angle can hamper progress

Example
[video=youtube;K862AoUca0c]http://www.youtube.com/watch?v=K862AoUca0c[/video]


Great job considering the constraints and the fact that you were having to swing from a squat position,personally I would have gotten onto my knees.Having said that I reckon if you had that same log vertically at waist height as in the O.P video pinute chopping demo, you would have gone through it in next to no time.
 
sumtinfancy said:
Hi,

As the title says, what is or are the main factors of or characteristics of a blade that make it good at chopping? ...So that's why I got to thinking about what is the most important ingredient which goes into making a blade a great chopper, It seems like in the case of the Filipino sword, the very sharp edge is what helped it get through the log, but surely a sharp edge is not enough on its own, surely weight,shape, grind of a blade all play a role?
Click to expand...

The most important ingredient is skill.

n2s
 
sumtinfancy said:
Yes, but I was basing my questions on the assumption that we have equally experienced/skilled wielders, so the one with the better tool will ultimately have better results.No?
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There are no "better tools". Once you get passed the basics the functionality is there, you can enhance the finish, the sheath and the furniture, but steel will basically cut like steel.

n2s
 
not2sharp said:
There are no "better tools". Once you get passed the basics the functionality is there, you can enhance the finish, the sheath and the furniture, but steel will basically cut like steel.

n2s
Click to expand...

Absurd.

"Functionality" dictates tool effectiveness and covers a WIDE range of integral attributes (including specific material property measurements, mass distribution, ergonomics if applicable, etc.), which are NOT equally implemented in tools designed for the same purpose, be they hand tools or power tools.

Also, "steel" does not "cut" at all, GEOMETRY cuts. The steel provides the structural support. And since you brought it up, steel provides greater structural support in thinner geometry than, for example, wood, which is why it makes a better material for construction of a cutting implement. *shrug*
 
You prevent the blade from becoming stuck by using alternating strokes to cut out a notch from the wood and knock out the chips with each cut.
If you still get the blade stuck then your notch is too wide and your chips are too thick.
Don't fault the blade for biting too deeply, that is up to the user.
 
chiral.grolim said:
Perhaps FortyTwoBlades can share some of his withdrawl techniques. A couple tips that I would offer include:
a) make the chop at an angle
- this allows the wood to split somewhat along the grain and move out of the way, reducing the pressure it can exert on the blade
- it also presents more media to the edge, reducing depth of penetration but also presenting less of the primary bevel for the wood/medium to grab hold of
b) chop into a fixed target (one you don't have to hold down yourself) with part of the edge that is sufficient distance from the handle to allow significant leverage to be applied when working the blade out of the cut
c) After the cut is complete, apply sharp/quick pressure on the handle to break the static friction, FIRST downward to bring the tip of the blade up, THEN upward - this extends the pivot point from the handle, allowing increased leverage to break the friction-hold.

Other thoughts?
Click to expand...

A lot depends on the specific conditions, but your observations are pretty on target. I usually use the third technique if the blade binds. It often doesn't take very much to pop the tool free. Of course, an ounce of prevention is worth a pound of cure from cutting your notch narrow enough to pop chips.
 
Fancier said:
You prevent the blade from becoming stuck by using alternating strokes to cut out a notch from the wood and knock out the chips with each cut.
If you still get the blade stuck then your notch is too wide and your chips are too thick.
Don't fault the blade for biting too deeply, that is up to the user.
Click to expand...

FortyTwoBlades said:
...cutting your notch narrow enough to pop chips.
Click to expand...

Width of the notch is determined by making TWO cuts, so it is imperative that the FIRST cut be easy to extract from as the second cut should release the chip and so suffer less binding friction. To avoid a high amount of binding friction on the first cuts, they must be made shallower. What I'd point out in this reply is the connection between "biting too deeply" and "your chips are too thick", as penetration depth determines chip thickness, and chip thickness measures the amount of wood removed from the notch which equates to the effectiveness of the chop - removing larger chunks per strike requires fewer strikes to complete the cut.

To avoid binding, the user must reduce the force (and penetration) of his/her machete strikes and reduce notch width. However, the notch width required for maximum effectiveness may be too narrow for the user to accurately strike (and the blade has an increasing tendency to glance off the side of the notch as depth increases). To accommodate this, the user must then widen the notch by cutting LOTS of narrow notches within a wider notch. This GREATLY increases the number of strikes (and time) required to complete the cut, resulting in something like this (starting at ~2:00):

[video=youtube;9iNWULVsue4]http://www.youtube.com/watch?v=9iNWULVsue4&feature=player_detailpage#t=115s[/video]

Now, the large knife in the above video is thick enough that it can be used to lever out thicker chunks (and force the wood apart to ease extraction), but this user either cannot or does not chop with the level of force required to penetrate very deep, and the length of the knife doesn't lend itself to this without use of a baton, which would be MUCH more effective (i.e. he could complete the task in a shorter period of time with significantly fewer strikes/cuts).
Here is a Condor Golok cutting softer wood, but the technique is excellent:

[video=youtube;H0e-Qi0yUQw]http://www.youtube.com/watch?v=H0e-Qi0yUQw[/video]

Sufficient structural support (i.e. thickness) to apply such leverage helps make a tool a better wood-chopper. For a thinner machete, leverage is reduced because the blade bends easily once bound. However, if the target is sufficiently fixed and the strike point is sufficient distance from the end of the handle, the extraction technique mentioned above and shown in the video allows the user to make those deep cuts and still get the blade out of the cut with relative ease, allowing for thicker chunks = fewer cuts = less time/effort = increased efficiency.

(the audio is jumbled in this video - is it just me? Machete binding at 4:00)
[video=youtube;9lmEoZ6xwbY]http://www.youtube.com/watch?feature=player_detailpage&v=9lmEoZ6xwbY#t=238s[/video]


Someone with a lot of machete and seasoned hardwood (e.g. oak) on hand may need to run an experiment measuring the notch width & penetration depth found to be most effective at removing wood with minimal binding, depending on the tool... Anyone?
 
In circumstances where the blade can easily bind like in the last video I find it best to strike with the region just forward of the sweet spot. While it increases felt shock you can still deliver a heavy blow, but you have a longer lever if you need to break the blade free. I hate cutting perpendicular to small logs. Easy to get your blade stuck in a way that's difficult to remove because the log is light enough it want to go where the blade goes. Using the more forward region and slightly more reserved blows helps eliminate that. Even better, I like to lift an end and make diagonal cuts since the log is somewhat braced that way.
 
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