Questions about axe handles (fawns-foot to start with)

[littleknife]

littleknife, You take lots for granted. I believe I said... " Quote Originally Posted by Double Ott

There must be a reason as to why I developed a favorite axe for tasks...."

Tom

Double Ott, sorry if you mistook my intent.
I understood well what you have written, I just wanted to use your quote to further point out that there is a social and historical aspect to this whole question which at times and in given areas seems to oppose common sense and ergonomics.

I did not try to create the impression, that you were not aware of this, I just tried to use your quote as a starting point to discuss an important aspect.
I should have been more explicit regarding my post and sorry if it created a wrong impression in others.

 

[Square_peg]

Take a look at the video again. Does the axe appear to pivot on a point 5" above the poll? That's what Cook says it does.

 

[FortyTwoBlades]

You are right.

However, some of those South American axe head patterns with their long bits and absence of poll do not seem to be the epitome of a well balanced axe:

http://world-of-axes.com/products.php?PID=11

Please look at:

HACHA CASCO CON OJO OVALE (TYPO 334) CON MANGO LARGO 90CM

and

HACHA TYPO “CORTADORA”


Or look at the axes posted by 300Six in this thread:

http://www.bladeforums.com/forums/showthread.php/1247717-Axe-use-by-primative-tribes-in-the-Amazon

http://i1289.photobucket.com/albums/b505/bertvaningen53/Walterstradeaxe007Medium_zps6b7b2dc0.jpg

http://i1289.photobucket.com/albums/b505/bertvaningen53/Walterstradeaxe004Medium_zps23418408.jpg

None of those looks to be well balanced, unlike the nice Byscaian/Basque axes posted on the forum by Ugaldie or the Italian axes carried by you.

The one outfitted with a straight haft could be imbalanced, but often with those styles of heads the bit is much lighter than it would appear just looking at a photo. The unhafted ones could be brought into balance with an appropriately curved/offset handle. But that "cortadora" one would require some selective haft-matching for sure. My guess is it probably balances about 1/2" to 1" in front of the eye. If hung on a straight handle you'd need to close the hang, which would actually produce a similar effect to a curved handle. The disadvantage of such a method being that when properly hung in that manner only the point of the lower hand is inline with the axis of rotational balance which means that the off hand is then required to provide some counter-torque when using the sliding-hand method to compensate for being so far off-axis.

 

[littleknife]

The one outfitted with a straight haft could be imbalanced, but often with those styles of heads the bit is much lighter than it would appear just looking at a photo. The unhafted ones could be brought into balance with an appropriately curved/offset handle. But that "cortadora" one would require some selective haft-matching for sure. My guess is it probably balances about 1/2" to 1" in front of the eye. If hung on a straight handle you'd need to close the hang, which would actually produce a similar effect to a curved handle. The disadvantage of such a method being that when properly hung in that manner only the point of the lower hand is inline with the axis of rotational balance which means that the off hand is then required to provide some counter-torque when using the sliding-hand method to compensate for being so far off-axis.

FortyTwoPlades, thank you for taking the time to explain all this.
It wass very helpful, I learned a lot of new information. :thumbup::thumbup:

My experience of working with straight handled axes was with similar axes. Unfortunately, they were not hung in any way that would make them overall more balanced.
On the other hand, the straight handles themselves did not bother me too much.

 

[FortyTwoBlades]

FortyTwoPlades, thank you for taking the time to explain all this.
It wass very helpful, I learned a lot of new information. :thumbup::thumbup:

My experience of working with straight handled axes was with similar axes. Unfortunately, they were not hung in any way that would make them overall more balanced.
On the other hand, the straight handles themselves did not bother me too much.

It's one of the reason why poll-less (or minimal-poll) axes with thin bits and straight or straight-ish handles tend to have the heel well behind the toe. It closes the effective hang to bring the edge in proper alignment with the radius of the stroke. Such axes do require a straight haft of a particular length in order to perform properly, or else have a haft with increasingly extreme bend to them the shorter you make the handle.

 

[littleknife]

Take a look at the video again. Does the axe appear to pivot on a point 5" above the poll? That's what Cook says it does.

No, the axe head definitely does not pivot on a point 5” above the poll.

But I don’t think that is what Cook is saying:

http://www.oldjimbo.com/survival/aas.html

http://www.oldjimbo.com/survival/axe1c.jpg

http://www.oldjimbo.com/survival/pivot1.jpg

Square_peg, If I understand it correctly, what Cook says is that there is a difference the way a straight handled axe bit and a curved handled axe bit would pivot, if both are held with the same wrist position.
Held with the same wrist position, most curved handles position the edge of the axe "further down” from the edge position the same axe would be if hung on a straight handle, increasing this way the “effective length of the fore-section" of the axe (again, the wrist position and the axe head are the same, only the handle shape differs).

I personally think, that Cook’s argument is that at constant wrist position/grip, at same handle lengths and speaking of the same axe head, there is a variable effect of change in the effective length of the fore-section, which depends on the shape of the handle.
I think this argument is correct.

Now, if I understand it correctly, in addition to this, from this argument Cook concludes further, that this effect inevitably leads to variable degrees of inaccuracy during real life axe swinging and striking.

However, the wrist and grip can correct these effects, so in the end, the achieved accuracy might not be an issue.
The real question for me is, which handle shape allows for a more effortless, less wrist-straining swing and strike?

 

[chuxwan]

Excellent discussion thread so far! I'd like to inject another factor into this frenzy which I do not believe has been given proper attention, which is a more thorough investigation of the type of force exerted on the curved axe handle with a fawn's foot. It seems to me that the bottom-most, angled portion of the handle as well as the distinctly curved part of the fawn's foot provide important surface area for enabling user's bottom hand to pull downwards, or directly away from the axe head. I believe this enhanced surface for pulling in a secure fashion is the entire basis for a user's ability to create the "snap" at the end of the stroke, or when using any curved-handled knife or hatchet. When you "snap" the tool, you are taking advantage of applying easy downward force to accelerate the head. In other words, to increase the head speed requires either a push or a pull force on the handle, the pull force being the only way to physically achieve enough force in the right way to accelerate the head noticeably - this pulling ability is greatly enhanced by the fawn's foot / curved haft. In the picture below, observe how force applied A will encourage rotation of the head in direction B around a pivot point in the general vicinity of point C.

 

[littleknife]

Chuxwan, you may be right, but I am trying to understand the effect of pulling on the snap.
What makes it difficult for me to imagine this is the fact, that most fawn foot handles I have seen, don’t have a pronounced flare like the one on khukuris or Saami knives.
The only axe I have seen so far that was suitable IMHO for this application of force was the 2400 year old one found in Ireland and posted above by FortyTwoBlades. It had a pronounced flare, which might provide enough purchase to pull it efficiently.

IMHO the end swells and knobs are used not so much for pulling during the snap, but to prevent the hand to slip off completely at the end of the swing.

Also, if the pull effect was so important, it would be very easy to incorporate such a flare at the end of straight handles too. Interestingly, most straight handles lack such a flare.

As far as I remember, I have never had to pull the end of an axe handle in order to make a “snap”, supposing that my conscious perception regarding what was happening was indeed correct.
Once again, you may be right, and I might have used axes the wrong way or perceived the wrong way what was actually happening.

 

[FortyTwoBlades]

Chuxwan, you may be right, but I am trying to understand the effect of pulling on the snap.
What makes it difficult for me to imagine this is the fact, that most fawn foot handles I have seen, don’t have a pronounced flare like the one on khukuris or Saami knives.
The only axe I have seen so far that was suitable IMHO for this application of force was the 2400 year old one found in Ireland and posted above by FortyTwoBlades. It had a pronounced flare, which might provide enough purchase to pull it efficiently.

IMHO the end swells and knobs are used not so much for pulling during the snap, but to prevent the hand to slip off completely at the end of the swing.

Also, if the pull effect was so important, it would be very easy to incorporate such a flare at the end of straight handles too. Interestingly, most straight handles lack such a flare.

As far as I remember, I have never had to pull the end of an axe handle in order to make a “snap”, supposing that my conscious perception regarding what was happening was indeed correct.
Once again, you may be right, and I might have used axes the wrong way or perceived the wrong way what was actually happening.

The snap comes from a pressure shift of the fingers (moving from forefingers to wring/pinky) and the wrists. It's not a matter of "pulling"--it's more like it's about squeezing, and the curve acts as a lever. Now, if you don't employ that shift then you're simply going to have the forward-offset effect compared to the same swing with a straight handle, in which case you're increasing your impulse.

 

[chuxwan]

The snap comes from a pressure shift of the fingers (moving from forefingers to wring/pinky) and the wrists. It's not a matter of "pulling"--it's more like it's about squeezing, and the curve acts as a lever. Now, if you don't employ that shift then you're simply going to have the forward-offset effect compared to the same swing with a straight handle, in which case you're increasing your impulse.

Yes, about pressure shift, but it is absolutely a pulling force. You generate pull towards your body to increase the speed of the axe head. Note, however, that the fore may not be expressed as a pulling motion, but as a way of simply holding the swell as you reach the end of your stroke (your arms are straight and opened, they're not going any further, but the axe head is still in motion).

I also wonder about the effect of such a snap on the cutting edge meeting material. Does it add any slicing effect? Not a noticeable one, anyway.

 

[halfaxe]

I think Cook spends 80% analysis on axe physics and 20% on body physics. Actual axe use involves 80% body physics and 20% axe physics.

 

[FortyTwoBlades]

Yes, about pressure shift, but it is absolutely a pulling force. You generate pull towards your body to increase the speed of the axe head. Note, however, that the fore may not be expressed as a pulling motion, but as a way of simply holding the swell as you reach the end of your stroke (your arms are straight and opened, they're not going any further, but the axe head is still in motion).

I also wonder about the effect of such a snap on the cutting edge meeting material. Does it add any slicing effect? Not a noticeable one, anyway.

Yes, it's technically a pulling force, but I meant it in terms of clarification since "pulling" the cut could be taken as doing so at a larger level--it makes it sound like a motion driven from the arms rather than a motion chiefly focused on the fingers and wrist.

And yeah I don't think that it'll add any slicing effect unless you add a larger drawing motion from the arms. I do find that when making very deep cuts that might otherwise bind a drawing action can be used to avoid static friction, but if too much drawing is used then you may end up decreasing your penetration at the same time so it's not always an appropriate technique. Generally delivering such a blow with the heel of a curved bit works best since you're then pulling the deepest part of the bit through the stroke.

 

[littleknife]

I still have difficulty imagining this “pulling” force during the snap.
If we describe the motion of the axe during the snap as that of a lever in rotation, the forces resulting the actual rotation cannot be pulling forces, since this would result in only a movement of the whole axe in the direction of the pull instead of a rotation.
As I understand (or misunderstand) it, the pulling force here is one which moves the whole axe, including the fulcrum of the rotation towards the user.
The fulcrum of rotation is so close to the end of the handle, that any complex force acting on the axe handle has to have a strong non-pulling component in order to result in a rotation. And the pulling component will just tug the whole axe (the fulcrum included), instead of contributing to the rotation.

On the other hand, maybe to achieve this rotation, some joints in the arm/hand of the user are executing a pulling motion. Is this what you are talking about? If yes, then the effective forces transmitted by the hand of the user, i.e. the forces acting on the axe handle during the snap still have to be ones resulting a rotation rather than a tug.

 

[rjdankert]

This guy has some ideas about accuracy.

"Go behind the scenes with multiple world-championship title-holder David Bolstad as he breaks down the standing block chop discipline, which mimics the felling of a tree."

[video=youtube;GQZacqMrA9w]https://www.youtube.com/watch?v=GQZacqMrA9w[/video]

 

[cityofthesouth]

Chuxwan, you may be right, but I am trying to understand the effect of pulling on the snap.
What makes it difficult for me to imagine this is the fact, that most fawn foot handles I have seen, don’t have a pronounced flare like the one on khukuris or Saami knives.
The only axe I have seen so far that was suitable IMHO for this application of force was the 2400 year old one found in Ireland and posted above by FortyTwoBlades. It had a pronounced flare, which might provide enough purchase to pull it efficiently.

IMHO the end swells and knobs are used not so much for pulling during the snap, but to prevent the hand to slip off completely at the end of the swing.

Also, if the pull effect was so important, it would be very easy to incorporate such a flare at the end of straight handles too. Interestingly, most straight handles lack such a flare.

As far as I remember, I have never had to pull the end of an axe handle in order to make a “snap”, supposing that my conscious perception regarding what was happening was indeed correct.
Once again, you may be right, and I might have used axes the wrong way or perceived the wrong way what was actually happening.

The Penn Rail Road specs, that we see all the time, call for 1-5/8" in the swell and I have an old handle that is 2 full inches across the swell and I'd bet 1-3/4 was common. The swells were also much more abrupt than most of what has been made in the last decades, with more hook. I think what we're talking about are at least two different forces at work. We have talked about conservation of angular momentum (can we start calling this CAM?) where by pulling the axe toward the body you increase the speed of the head. This is usually likened to an ice skater pulling her arms in as she spins and you see it in virtually every swing in Timber Sports. I think snap is a little different in that it is something you do with your hands and fingers to sort of leverage the axe once it has come around. If you feel yourself applying power at the last second in your hips and core, then you are probably experiencing CAM.

I think the entire design is subconscious - in the same way you just automatically know how to use it. I am sure that some brilliant people could have applied math or physics to design them, but I think humans, as tool users, just understood what was needed and made it. I would guess that it happened simultaneously in different places around the country and the originators had some idea, maybe from having seen something in the past and taking it to the next step, or just from having a need and an imagination. Blacksmiths start putting polls on the axes, some wood worker makes himself the best handle he could think of, the two get together, small communities, word spreads. When you figure that almost every person living at that time used a variety of hand crafting skills in everyday life, it's not a stretch to think the idea could have spread very quickly.

 

[300Six]

Since we've become pre-occupied with the topic of swells and curves here are a few shots of vintage Walters Axe hafts. The top one, although dainty and nicely sculpted, is not comfortable for me. The shape lends itself to forearm-action chopping (ie via the accompanying hatchet) rather than using arms. The next two hafts are typical of what we're discussing here and are perfectly functional but the bottom haft is the one that I personally most enjoy using.
Before folks get all armchair-worked up about what they hear or read they really owe it to themselves to try out as many different hafts as they can before committing.

 

[Chignecto Woodsman]

This guy has some ideas about accuracy.

"Go behind the scenes with multiple world-championship title-holder David Bolstad as he breaks down the standing block chop discipline, which mimics the felling of a tree."

[video=youtube;GQZacqMrA9w]https://www.youtube.com/watch?v=GQZacqMrA9w[/video]

Good video. I'm no competitor but I think his point that moving any part of your body will take away your accuracy is key. It seems to me that the accuracy happens before and at the very start of your chop, redirection in the swing seems to really only make sense to limit damage when you know something went wrong. If I know something is off or I think about the wrong thing or something catches my eye then I may not be hitting in the right spot. But when I envision hitting perfectly and start the swing correctly I will hit good and hard.

I imagine that most of accuracy takes place within the start of a swing. Would this mean then that accuracy between straight or curved handles depends on the starting position of your swing? It seems the curved handle would start farther back than the straight handle, and it is this angled position which would essentially cause an increase in eye pivot in that your axe begins farther away with a curved handle and ends in a slightly altered position from that of a straight-handled swing. Or, the angle essentially adds distance to the head because your wrist snap at the end of the curved-handled swing creates that extra distance that is in the offset handle. Or still another possibility, as I suggested earlier the difference in pivot distance has to be increased by situating the fawn's foot forward from the real pivot in the eye so that the hang is not too open.

The first and last seem most likely to me, and would result in your axe starting the same distance further back in your swing (I think it is a collection of these elements together, is what I'm trying to say). Cook simply doesn't show all of the details in the problem. It is not the 4-1/2" bit that causes the imbalance, it is the 1/4" or so between the true center of the axe and its pivot axis which causes the first imbalance in a single-bit axe. The other 4-1/2" is that the angle of the curved handle effectively lines up with the second edge of a double-bitted axe. All things being equal, when you start a swing and your wrist is backed up as far as possible (it is essentially in the same position no matter which handle) the curved handle can cause the head to be as far away as where the back edge of a double-bit would be - when compared with the straight handle. This means that the pivot axis is in fact doubled, or perhaps even slightly more than doubled.

The straight-handled axe starts closer to the cut and ends at a natural point of movement. The curved-handled axe starts farther away from the cut and ends too soon. You get extra power at the expense of less control.

Given that the start of a swing is the most important part of accuracy this would make sense that a curved handle causes more wobble and is less accurate, there is simply more distance to cover in which wobbling may occur, and less time to make any corrections. The position of the axe in regards to the curved handle essentially doubles its length.

 

[FortyTwoBlades]

I still have difficulty imagining this “pulling” force during the snap.
If we describe the motion of the axe during the snap as that of a lever in rotation, the forces resulting the actual rotation cannot be pulling forces, since this would result in only a movement of the whole axe in the direction of the pull instead of a rotation.
As I understand (or misunderstand) it, the pulling force here is one which moves the whole axe, including the fulcrum of the rotation towards the user.
The fulcrum of rotation is so close to the end of the handle, that any complex force acting on the axe handle has to have a strong non-pulling component in order to result in a rotation. And the pulling component will just tug the whole axe (the fulcrum included), instead of contributing to the rotation.

On the other hand, maybe to achieve this rotation, some joints in the arm/hand of the user are executing a pulling motion. Is this what you are talking about? If yes, then the effective forces transmitted by the hand of the user, i.e. the forces acting on the axe handle during the snap still have to be ones resulting a rotation rather than a tug.

THIS article on baseball bats demonstrates how the actual pivot point of the bat during impact was a few inches beyond the bottom of the bat itself. The stroke of an axe is a little different, but the concept is similar. During the beginning of the stroke the pivot is a little past the end of the handle, and then tightens to the hands just before impact, and it's during that transition that the action becomes a pull, as the lower hand tightens to deliver its squeeze. The handle just before the squeeze is pivoting on the top edge of the lower hand as the top hand is sliding down to tighten the radius and the final squeeze raises the point of pivot up into the hand just before impact.

 

[chuxwan]

That may be a factor, except that a curved handle will not necessarily start further from the cut, being that the curve in this case is not a specific handle shape. Axes with an "s" curve to the handle will start further back. What I mean by the "s" curve is that the handle underneath the eye curves the direction of the bit before going back the other way. This particular part of the curve seems to me beneficial for accuracy, as your top hand gripping here will create more of a "leading" effect, where the weight of the axe head is trailing [more] behind your top hand at the beginning of the swing. Swinging with trailing weight will always be more accurate than with leading weight, except when it isn't. That whole concept assumes an unskilled user. Being accurate with anything will make those points negligible.

 

[FortyTwoBlades]

Doing some experimentation, the squeeze of the snap is something that occurs with both straight and curved handles. The curve just creates even more travel (this being with the off hand sliding down the haft rather than a moulinet or other techniques) so I think it's back to that increase in impulse.