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

[Chignecto Woodsman]

Cook was trying to prove that IF your swing wasn't perfectly accurate, it would be even less accurate with a curved handle. There is nothing inherent in either handle that would cause or prevent any twisting given a similar cross section. And it would be the opposite, you have to make smaller wrist adjustments because the effect of the correction is greater in a curved handle - by his logic, not mine.

Amazingly he couldn't even draw an axe ..... but by his logic he shows that with a straight handle a 5 degree change results in .39" deviation and .78" with a curved - ie less movement with the curved handle equals more deviation. Which is nonsense.

More importantly, whether one is more accurate over another doesn't make much difference to someone who is accurate with both. And what is particularly amazing about his argument is that the edge of the bit must theoretically be exactly inline with the handle for maximum accuracy potential. In fact, in that way, the curved handle accomplishes exactly what he thinks is better about the straight handle, by setting the head further back. He even draws the line straight through the tool and it's closer to the bit! He contradicts himself in his own work.

What I meant by that was that one would have to make a greater number of wrist adjustments. It would be like very tight steering in a car, you can make very tight turns but you also have to be increasingly sensitive in your adjustments and make more of them. The frequent adjustments when swinging an axe could be more damaging to your wrists than a rare overextension, or at least more tiring and so negate the energy saved in the comfortable grip. However, if you are off in your swing this may require a larger adjustment due to the problem of curved handles missing on two planes - a more sensitive adjustment perhaps but one that takes greater effort and skill to achieve.

I don't get this one, he couldn't draw an axe so therefore he was wrong? That's not an argument, and not really fair. I see a lot of people saying his argument was wrong but not offering why and certainly not offering anything as a counter, only conjecture and hearsay (if it's more accurate it's more accurate, plain and simple, so if you prefer the curved handle for other reasons it should be for those reasons and not having to deny the accuracy of the straight handle). What he explained is a geometric fact, if you turn something off angle it will increase the deviation as it has created a second plane. Essentially the curved haft acts like something of a lever, and if you turn the axe over at the curved foot the axe will spin and twist whereas a straight haft will only spin. This, again, means that the slight deviation of the axe does not affect only the angle of penetration - say 47 degrees rather than 50 - but also the angle line of the cut, you don't cut cleanly and sever part of the notch you already created; two planes which can lead to less efficiency. If you take a couple of axes and try spinning them slightly from the wrist and try holding in different spots with your other hand you should feel that the straight haft only spins while the curved haft sometimes spins and sometimes deviates to the side. You can feel it pushing against your hand, should be downwards and in the same direction the axe is spinning on the downward side.

It would perhaps be useful as well to take a haft by itself and see how it spins without the head. You should find that the straight haft spins almost perfectly with the center of the haft while the curved half spins at an axis closer to the front or bit side. This would mean that the axis length is indeed doubled, approximately, and thus confirms what Cook is saying. Or in other words, deviation of the axe is equal to the offset pivot of the head plus the handle. The longer the single-bit axe is in its bit mass, as well as the greater curve of the handle, the greater the possible deviation. (He doesn't say all of this stuff, obviously, so I am trying to clarify what it means from my understanding of it.)

Further, it is not the handle that must be in line with the bit, rather the axis of pivot of the head should be in line with the axis of pivot of the handle. A well-balanced axe should have its axis somewhere near the center of the eye, this is rare in a single-bit, generally it is closer to the bit. Most are 1/4"-1/2" back from the beginning of the eye according to Cook. What I suspect then is that there would be a third aspect to deviation: total deviation equals the head's off-axis distance plus the handle's off-axis distance plus the offset distance between both handle and head pivot points. Essentially this is the same thing, only clarifying what is missing in Cook's outline. Basically if the two axes are in line, head with haft, then the angle of the curved haft will be much less and so deviate less. This would be why curved hafts tend to be farther back than the straight hafts, because the fawn's foot should meet up with the head's axis. But overall this would mean the handle is a farther distance away from the real central axis of the axe, and the mass and force offcenter contributes to total deviation.

To clarify look at these two axes.

The straight haft would have its pivot almost in the center of the handle, whereas the curved haft pivots almost at the edge of the swell-curve. What's worse is that the curved haft tends to be even further forward from the head axis so as not to leave the edge too open in the heel. Meaning that this axe would deviate up to three times as much as the straight handle double-bit and approximately twice the single-bit shown here. It seems the curved hafts are brought forward to try and compensate for the off angle and prevent off-balance towards the heel.

In short, the curved handle creates a second axis for the axe which is offline from the axis in the eye. You then have to counter the real axis of the head with the false/offset axis of the curved haft, and the greater the curve the greater possible deviation. Essentially, the farther your hand is away from the pivot point the greater the possible deviation. Curved handles and handles deviating from the pivot points compound inaccurate swings.

This is not to say you're wrong for preferring one type of handle, and I don't think that Cook was trying to suggest that either. All he was trying to do was carve out an ideal of the axe, or The Efficient Ax. As far as I can tell, no one else has written so extensively on axes and axe geometry, certainly not suggesting what the ideal axe would be as a whole.

I agree with BG_Farmer, this shouldn't be about one certainly being better as there are positives to both handle types, as many of us have been pointing out. I think people should try out the different handles and even different hangs. I will also admit that Cook, or my interpretation of him, could be wrong, I would just like to see some proof of this. I will even give away what I think is proof. Set up several axes with straight handles and good and bad hangs, and do the same with curved handles. Do the axis of pivot test and see just how far the axes are off from each other. This should give some scientific data for what is likely to be off in accuracy, and then do some testing to see if the numbers prove true. Technically the greater the curve, the worse the hang, and the worse the balance of the head the longer the distance the axis should be from the center of the eye.

Basically Cook's images give a general idea of the outcome of a real pivot test.

Phew, that's a lot of words. Sorry, gentlemen, I will try and compact that down if need be.

 

[rjdankert]

Check out some Basque endurance timbersports chopping events. . .

2012 Basque country's axemen final championship 1-4
https://www.youtube.com/watch?v=0HM94DCLu1w

In this event the choppers did two rows

 

[FortyTwoBlades]

What I meant by that was that one would have to make a greater number of wrist adjustments. It would be like very tight steering in a car, you can make very tight turns but you also have to be increasingly sensitive in your adjustments and make more of them. The frequent adjustments when swinging an axe could be more damaging to your wrists than a rare overextension, or at least more tiring and so negate the energy saved in the comfortable grip. However, if you are off in your swing this may require a larger adjustment due to the problem of curved handles missing on two planes - a more sensitive adjustment perhaps but one that takes greater effort and skill to achieve.

I don't get this one, he couldn't draw an axe so therefore he was wrong? That's not an argument, and not really fair. I see a lot of people saying his argument was wrong but not offering why and certainly not offering anything as a counter, only conjecture and hearsay (if it's more accurate it's more accurate, plain and simple, so if you prefer the curved handle for other reasons it should be for those reasons and not having to deny the accuracy of the straight handle). What he explained is a geometric fact, if you turn something off angle it will increase the deviation as it has created a second plane. Essentially the curved haft acts like something of a lever, and if you turn the axe over at the curved foot the axe will spin and twist whereas a straight haft will only spin. This, again, means that the slight deviation of the axe does not affect only the angle of penetration - say 47 degrees rather than 50 - but also the angle line of the cut, you don't cut cleanly and sever part of the notch you already created; two planes which can lead to less efficiency. If you take a couple of axes and try spinning them slightly from the wrist and try holding in different spots with your other hand you should feel that the straight haft only spins while the curved haft sometimes spins and sometimes deviates to the side. You can feel it pushing against your hand, should be downwards and in the same direction the axe is spinning on the downward side.

It would perhaps be useful as well to take a haft by itself and see how it spins without the head. You should find that the straight haft spins almost perfectly with the center of the haft while the curved half spins at an axis closer to the front or bit side. This would mean that the axis length is indeed doubled, approximately, and thus confirms what Cook is saying. Or in other words, deviation of the axe is equal to the offset pivot of the head plus the handle. The longer the single-bit axe is in its bit mass, as well as the greater curve of the handle, the greater the possible deviation. (He doesn't say all of this stuff, obviously, so I am trying to clarify what it means from my understanding of it.)

Further, it is not the handle that must be in line with the bit, rather the axis of pivot of the head should be in line with the axis of pivot of the handle. A well-balanced axe should have its axis somewhere near the center of the eye, this is rare in a single-bit, generally it is closer to the bit. Most are 1/4"-1/2" back from the beginning of the eye according to Cook. What I suspect then is that there would be a third aspect to deviation: total deviation equals the head's off-axis distance plus the handle's off-axis distance plus the offset distance between both handle and head pivot points. Essentially this is the same thing, only clarifying what is missing in Cook's outline. Basically if the two axes are in line, head with haft, then the angle of the curved haft will be much less and so deviate less. This would be why curved hafts tend to be farther back than the straight hafts, because the fawn's foot should meet up with the head's axis. But overall this would mean the handle is a farther distance away from the real central axis of the axe, and the mass and force offcenter contributes to total deviation.

To clarify look at these two axes.

The straight haft would have its pivot almost in the center of the handle, whereas the curved haft pivots almost at the edge of the swell-curve. What's worse is that the curved haft tends to be even further forward from the head axis so as not to leave the edge too open in the heel. Meaning that this axe would deviate up to three times as much as the straight handle double-bit and approximately twice the single-bit shown here. It seems the curved hafts are brought forward to try and compensate for the off angle and prevent off-balance towards the heel.

In short, the curved handle creates a second axis for the axe which is offline from the axis in the eye. You then have to counter the real axis of the head with the false/offset axis of the curved haft, and the greater the curve the greater possible deviation. Essentially, the farther your hand is away from the pivot point the greater the possible deviation. Curved handles and handles deviating from the pivot points compound inaccurate swings.

This is not to say you're wrong for preferring one type of handle, and I don't think that Cook was trying to suggest that either. All he was trying to do was carve out an ideal of the axe, or The Efficient Ax. As far as I can tell, no one else has written so extensively on axes and axe geometry, certainly not suggesting what the ideal axe would be as a whole.

I agree with BG_Farmer, this shouldn't be about one certainly being better as there are positives to both handle types, as many of us have been pointing out. I think people should try out the different handles and even different hangs. I will also admit that Cook, or my interpretation of him, could be wrong, I would just like to see some proof of this. I will even give away what I think is proof. Set up several axes with straight handles and good and bad hangs, and do the same with curved handles. Do the axis of pivot test and see just how far the axes are off from each other. This should give some scientific data for what is likely to be off in accuracy, and then do some testing to see if the numbers prove true. Technically the greater the curve, the worse the hang, and the worse the balance of the head the longer the distance the axis should be from the center of the eye.

Basically Cook's images give a general idea of the outcome of a real pivot test.

Phew, that's a lot of words. Sorry, gentlemen, I will try and compact that down if need be.

Good post. To further complicate things, let's not forget about the fact that a curved handle may either curve forward or rearward of the axis of rotational balance, or remain square on top of it. The same goes for axes with straight handles but offset necks. I maintain that it's just one minor element of a much larger picture. What matters most are:

1) The location of the real axis of rotational balance.

2) The position of the hands relative to that axis.

3) The position of the edge relative to that axis, including the hang (which will adjust the presentation of the cutting line.)

How you arrive at a harmonious balance of those factors is up to you, and there are countless ways to do it. A curve in the handle may or may not have any influence on performance because it depends on the specific nature and placement of the curve and how it is used in conjunction with your chopping style.

 

[Square_peg]

This is an interesting discussion! I doubt any mere facts will change my mind, as i simply prefer straight handles over the range of things I do with an axe and I like the look. For those who feel the other way, I'm just as happy to let them be that way.

Of my two current favorites one is straight and one is curved. I don't actually find much difference between them. An inch of difference in length is more important than straight vs curved to me. I like a large unclipped fawn's foot best. But if a straight haft has a good abrupt swell it'll do just fine for me.

 

[cityofthesouth]

First of all, congratulations, that was an epic tirade. I love it.

It would be like very tight steering in a car, you can make very tight turns but you also have to be increasingly sensitive in your adjustments

This is precisely my point, so well done again. I don't take issue with the idea lengthening the distance of the pivot from the bit, increases the deviation if a twist were to occur (I think I said that but that's ok). I take issue with the fact that it's not real world. The real issue is that the lack of accuracy has to exist. Why should it? A race car driver wants more response from his car, why, because he's a professional. Someone who swung an axe all day every day is a professional IMO, therefore what Cook calls a negative, I am calling a positive. You said it yourself. So Cook wanted to find something wrong and he looked at the problem from an amateur's perspective - ie someone who didn't have accuracy to begin with. But for someone who does, they want better response from their tool with more minute input. The argument against what he's saying is, it's not an inherent trait of the handle itself that influences accuracy. There may be a trait which affects poor accuracy, but does not create it or remove it. And all of this is based on the notion that the axe is being swung as if on a fixed pendulum (I'm trying to say, as if the pivot were rigidly fixed in place), but that's not the case. The user alters everything, the handle and head shape alter everything. So it's presented as the overreaching de facto issue he takes with curved handles, when in fact it's really just overstated when you consider all the other actual forces at work. Those forces are really much more important in the case for or against a curved handle. I'd also point out that the ability to purposefully twist the axe may have been desired not just because of sensitivity but also to generate a twist on impact.

I don't get this one, he couldn't draw an axe so therefore he was wrong?

Yes! ...... but seriously, it wasn't an argument so there's that. I didn't say what you just said, those are your own words and assumptions. It was a straight up insult to his drawing skills and I maintain that he couldn't draw an axe. And while we're talking about drawings, here's one for ya. It's all arbitrary, just like Cook's. So to be fair, this is also nonsense, just like his. The core concept is there, the real world application, not really.

pivot_axis_deviation by city_ofthe_south, on Flickr

 

[FortyTwoBlades]

First of all, congratulations, that was an epic tirade. I love it.



This is precisely my point, so well done again. I don't take issue with the idea lengthening the distance of the pivot from the bit, increases the deviation if a twist were to occur (I think I said that but that's ok). I take issue with the fact that it's not real world. The real issue is that the lack of accuracy has to exist. Why should it? A race car driver wants more response from his car, why, because he's a professional. Someone who swung an axe all day every day is a professional IMO, therefore what Cook calls a negative, I am calling a positive. You said it yourself. So Cook wanted to find something wrong and he looked at the problem from an amateur's perspective - ie someone who didn't have accuracy to begin with. But for someone who does, they want better response from their tool with more minute input. The argument against what he's saying is, it's not an inherent trait of the handle itself that influences accuracy. There may be a trait which affects poor accuracy, but does not create it or remove it. And all of this is based on the notion that the axe is being swung as if on a fixed pendulum (I'm trying to say, as if the pivot were rigidly fixed in place), but that's not the case. The user alters everything, the handle and head shape alter everything. So it's presented as the overreaching de facto issue he takes with curved handles, when in fact it's really just overstated when you consider all the other actual forces at work. Those forces are really much more important in the case for or against a curved handle. I'd also point out that the ability to purposefully twist the axe may have been desired not just because of sensitivity but also to generate a twist on impact.




Yes! ...... but seriously, it wasn't an argument so there's that. I didn't say what you just said, those are your own words and assumptions. It was a straight up insult to his drawing skills and I maintain that he couldn't draw an axe. And while we're talking about drawings, here's one for ya. It's all arbitrary, just like Cook's. So to be fair, this is also nonsense, just like his. The core concept is there, the real world application, not really.

pivot_axis_deviation by city_ofthe_south, on Flickr

I'd argue that the core principle is a valid one but distance of the edge from the axis of rotational balance is really only half of the matter. It has to be taken into account with balance, because the worse the balance of the tool the more it naturally wants to rotate in the hand, and that degree of rotation will be magnified by the distance of the hands from the axis due to leverage in addition to the radius effect. Basically, if you have a well-balanced axe then the magnitude of influence of the effective bit length is lowered, though it still has some. A less-than-perfectly balanced axe will make matters of bit length known in short order. This will not be an issue if doing work where the edge is oriented towards the ground, but during felling cuts it's a good deal more noticeable.

 

[Chignecto Woodsman]

Excellent points, FortyTwo. You said more than I did with 10% of the words.

City, your argument is well said. There is a potential benefit for a skilled user to only have to make minor corrections, but I think this may be a matter of when the error occurs. Are these errors occurring at the beginning or in the middle of the swing? I'm guessing the benefit is in the start of the swing for a curved handle, especially considering what FortyTwo said in regards to wobble and deviation. You may be able to make sensitive readjustments with the curved handle, but the problem remains that you have to make more of them in compensating for what is essentially a more imbalanced axe.

I think you are correct that the curve and fawn's foot may have developed to twist on impact, or when withdrawing, especially when cutting very low as most did in felling. Check this video:
http://youtu.be/wHGHrzfq2_c

And it seems both old-timers and racing competitors customise their own handles for grip and movement. So it is preference to a certain degree, but there are a series of pros and cons to identify and ways to modify the handle for these results. I won't speculate any further today since I have to save my energy for snow-shoeing, but hopefully people can clarify some of these other aspects, where to curve the handle for specific traits or to leave it straight, and when to be behind or in front of the pivot.

 

[300Six]

A "picture is worth a thousand words"! And these two shots are exquisite! Thank you. Allows anyone with some experience to 'cut through the crap'. The quality-conscious Swedes lost out on mass-manufacture competitiveness already 40 years ago and yet managed to stay afloat through 'boutique' offerings of otherwise 'entirely uneconomical' implements.
Betcha neither of the two featured haft options (even though their curved version is straighter than any current n. American offering) are an impediment (in any way) to actually chopping wood.

 

[Square_peg]

Cook is dead wrong. His error is that he's confusing the grip angle with the axis of pivot. You pivot an axe with your forearm. (Having two bones in the forearm is what allows this twisting of the forearm.) You don't pivot an axe by relaxing your grip and letting the haft twist in your grip.

[video=youtube_share;DZ-IB35HCBo]http://youtu.be/DZ-IB35HCBo[/video]


Look at it this way. Suppose you join to pieces of wood together with a miter joint.

Twisting on the right end of the stick results in the left end twisting in line with the stick not in line with the miter joint. Half of the stick won't twist on line 'A'.

It will all twist along line 'B'.

It's the same with your forearm joined to the axe handle via a curved grip.

The axe doesn't pivot along line 'A'. It pivots along line 'B'. Watch the video again.

Some people will argue this forever and never be convinced. I can't change that. But I know that Cook is dead wrong and I can't make it any clearer. Either you get it or you don't.

 

[FortyTwoBlades]

Cook is dead wrong. His error is that he's confusing the grip angle with the axis of pivot. You pivot an axe with your forearm. (Having two bones in the forearm is what allows this twisting of the forearm.) You don't pivot an axe by relaxing your grip and letting the haft twist in your grip.

Good post. Total agreement.

 

[Chignecto Woodsman]

Those are good and useful images, Square_peg, and something I considered as well. However, the curved handle does introduce a second axis (as does the straight handle) because the human body isn't a machine. The mass and force of the person swinging the axe can easily overcome the counterbalance of the haft and head - skill and relaxing your grip only lessens deviation, it doesn't prevent it entirely. The axe and handle are not on a lathe and when turning the curved handle with the wrist there is an increased likelihood of twisting the axe and causing it to wobble off to the side. There is much clearer feedback with a straight handle. And we are talking about millimetres here, not something easily seen by the eye, so such tests are quite subjective. I would suggest trying to feel the turn of the axe with your second hand. It should be noted as well that the curved handle also causes potential for errors from your second hand as neither hand is on the handle axis. This can mean further deviation from the true axis in the head.

One problem that seems to be ignored is that many experienced people have seen and felt the difference in accuracy with a straight haft. And again, the double-bit most always shows a superior feel to even experienced users (this is mostly due to the head balance it seems, but shows how much of an effect minor balance changes can have). This was immediate for even those loggers who feared the double-bit at first. If not the curved haft and fawn's foot, then what is it? It is probable that curved hafts have more inconsistencies in production. As you can easily see in the images of the Gransfors axes the straight haft is at least close to being in line with the head axis, but is the curved haft? I don't think it is, and this seems to be a potential cause of inaccuracy if not an inherent flaw in the curved haft itself: the curved handle must be offset from the axis to compensate for the angle producing a more open edge, brought forward from the axis to keep the edge balanced between the center and heel. It would only really be possible to tell by removing the handle and testing its pivot. If someone could test the pivots of various axe handles perhaps we could tell, the only one I have currently not hafted was off-center and skewing towards the belly.

In short, the axis of pivot of the axe head does not negate the axe pivot of your arm, which is not a perfect lathe and cannot turn the curved axe as if it were on a machine as easily as turning the straight haft. Analagous to this would be the curved and straight bars in powerlifting, or lifting with machines. You can lift much more with a machine or curved bar as the technology compensates for forces. However, there is more room for error and potential bone and tendon damage due to the machines directing your movement with the force. A straight bar provides much better feedback to balance the bar, while not allowing you to lift as much. There is a lot more scientific data for this, so perhaps some research there may turn up some clues.

As I said before, Cook is using classic geometry to try and describe something extremely complex. Likely it is some calculus between the angle of the fawn's foot and the degree to which the curved haft is offset from the head's axis. This may mean that Cook's formula resulting in double deviation is exaggerated, but the problem is there; it would just take a lot of difficult calculations that I can neither do nor explain. The results are confirmed by many people in practise though.

 

[FortyTwoBlades]

Those are good and useful images, Square_peg, and something I considered as well. However, the curved handle does introduce a second axis (as does the straight handle) because the human body isn't a machine. The mass and force of the person swinging the axe can easily overcome the counterbalance of the haft and head - skill and relaxing your grip only lessens deviation, it doesn't prevent it entirely. The axe and handle are not on a lathe and when turning the curved handle with the wrist there is an increased likelihood of twisting the axe and causing it to wobble off to the side. There is much clearer feedback with a straight handle. And we are talking about millimetres here, not something easily seen by the eye, so such tests are quite subjective. I would suggest trying to feel the turn of the axe with your second hand. It should be noted as well that the curved handle also causes potential for errors from your second hand as neither hand is on the handle axis. This can mean further deviation from the true axis in the head.

One problem that seems to be ignored is that many experienced people have seen and felt the difference in accuracy with a straight haft. And again, the double-bit most always shows a superior feel to even experienced users (this is mostly due to the head balance it seems, but shows how much of an effect minor balance changes can have). This was immediate for even those loggers who feared the double-bit at first. If not the curved haft and fawn's foot, then what is it? It is probable that curved hafts have more inconsistencies in production. As you can easily see in the images of the Gransfors axes the straight haft is at least close to being in line with the head axis, but is the curved haft? I don't think it is, and this seems to be a potential cause of inaccuracy if not an inherent flaw in the curved haft itself: the curved handle must be offset from the axis to compensate for the angle producing a more open edge, brought forward from the axis to keep the edge balanced between the center and heel. It would only really be possible to tell by removing the handle and testing its pivot. If someone could test the pivots of various axe handles perhaps we could tell, the only one I have currently not hafted was off-center and skewing towards the belly.

In short, the axis of pivot of the axe head does not negate the axe pivot of your arm, which is not a perfect lathe and cannot turn the curved axe as if it were on a machine as easily as turning the straight haft. Analagous to this would be the curved and straight bars in powerlifting, or lifting with machines. You can lift much more with a machine or curved bar as the technology compensates for forces. However, there is more room for error and potential bone and tendon damage due to the machines directing your movement with the force. A straight bar provides much better feedback to balance the bar, while not allowing you to lift as much. There is a lot more scientific data for this, so perhaps some research there may turn up some clues.

As I said before, Cook is using classic geometry to try and describe something extremely complex. Likely it is some calculus between the angle of the fawn's foot and the degree to which the curved haft is offset from the head's axis. This may mean that Cook's formula resulting in double deviation is exaggerated, but the problem is there; it would just take a lot of difficult calculations that I can neither do nor explain. The results are confirmed by many people in practise though.

Also mostly true. Part of the problem is that when directed from the forearm you will experience what Square_peg describes, but if you explore the motions in an actual swing it's quite common to use at least some degree of snap from the wrists in the final moments of the blow if maximizing power, and when doing so that is where the curve comes into play to shorten the radius of the stroke. It's during those moments where the pump from the fingers and the tensing of the wrist occur that any imbalance in the head can cause a torque on the handle, and then you get the magnification effect that Cook describes. As you say, his methods are crude and the degree of research into it falls short of the mark, but it's a good start at least. It just can't be taken as good and truly correct either.

If anyone has a way of accurately and practically finding the true axis of rotational balance--especially when using fixed suspension points--do let me know. I've been working on some similar balancing concepts with scythes, and those are a lot less straight-forward than axe handles!

 

[Double Ott]

You guys are giving me a headache. Just grab your favorite axe for splitting and go out and split some wood. Or, grab your favorite axe for feeling and go out and fell a tree or two.

There must be a reason as to why I developed a favorite axe for tasks, limbing, splitting and felling. It is most likely what feels good and works well.

Simple....

Tom

 

[littleknife]

It's the same with your forearm joined to the axe handle via a curved grip.

The axe doesn't pivot along line 'A'. It pivots along line 'B'. Watch the video again.

Square_peg, actually this picture argues for Cook, and against the way you interpret it.

Imagine, that you are holding a straight stick or axe handle in the picture.
Along which line will it pivot?
Along line A, not B.
The determining factor here is your grip, and that depends ultimately on your wrist+palm+fingers rather than your forearm.

Now imagine, that you are holding a downward curving stick.
Along which line will it pivot?
The answer depends on what part/section of the stick you are talking about.
The portion you are gripping will pivot along line A. The end farthest away from you will be pivoting along a different line (depending on the extent of curvature it could be above line B, line B, or even below line B.

Think Flex Screwdriver. What line the bit pivots along when the flexible shaft of the screwdriver is bent?
The line along which the gripped handle pivots along or a different one?

Having said that, I do realize, that in real life things are more complicated, depending on the position and the strength the axe is gripped, the way the axe is swung (more linear or arched path), twisting on impact, etc.
Finally I just want to repeat, that there can a significant difference between the “accuracy" not only the straight and the curved handles, but also between that of different curved handles, and I suspect that some curved handles might be almost identical regarding the accuracy to the straight ones, if the “up” and “down” curvatures cancel out the offsetting effects of each other.

 

[littleknife]

There must be a reason as to why I developed a favorite axe for tasks, limbing, splitting and felling. It is most likely what feels good and works well.

Simple....

Tom

When people stopped making or at least customizing their own axe handles, it started to do not only with “what felt good and worked well”, but also what was available at the company store or at the local general store. Also, people tend to put up with a lot of less efficient tool designs or sometimes outright uncomfortable ones, if there is a strong social pressure for conformism. As an example, bearded axes are still sold and used in Southeastern Europe for felling, limbing, bucking and even firewood splitting, even though they are not very efficient or comfortable for those tasks.
Similarly, felling axes without polls are still sold and used in South America, even though the well balanced American axe with its substantial poll is clearly superior ergonomically.

 

[FortyTwoBlades]

Polls are not required for balancing an axe. They're just one method.

 

[littleknife]

Polls are not required for balancing an axe. They're just one method.

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.

 

[Square_peg]

Square_peg, actually this picture argues for Cook, and against the way you interpret it.

Imagine, that you are holding a straight stick or axe handle in the picture.
Along which line will it pivot?
Along line A, not B.
The determining factor here is your grip, and that depends ultimately on your wrist+palm+fingers rather than your forearm.

No. It can only pivot along line 'A' if you relax your grip and let it pivot on that axis. The pivot is in your forearm not your grip. The grip angle is simply the angle in which the two pieces (forearm and haft) are joined. It's not complicated.

If you hold a straight stick or straight axe haft then you will naturally change the tilt of your wrist. But the pivot will still be in your forearm and not in your grip. If anything a straight haft requires more tilt of the wrist.

 

[Double Ott]

When people stopped making or at least customizing their own axe handles, it started to do not only with “what felt good and worked well”, but also what was available at the company store or at the local general store. Also, people tend to put up with a lot of less efficient tool designs or sometimes outright uncomfortable ones, if there is a strong social pressure for conformism. As an example, bearded axes are still sold and used in Southeastern Europe for felling, limbing, bucking and even firewood splitting, even though they are not very efficient or comfortable for those tasks.
Similarly, felling axes without polls are still sold and used in South America, even though the well balanced American axe with its substantial poll is clearly superior ergonomically.

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

 

[littleknife]

No. It can only pivot along line 'A' if you relax your grip and let it pivot on that axis. The pivot is in your forearm not your grip. The grip angle is simply the angle in which the two pieces (forearm and haft) are joined. It's not complicated.

If you hold a straight stick or straight axe haft then you will naturally change the tilt of your wrist. But the pivot will still be in your forearm and not in your grip. If anything a straight haft requires more tilt of the wrist.

Well, I respectfully disagree with the conclusions you draw from this picture regarding the whole process of the axe strike.

There is more to swinging an axe than just holding it in a static position.
This is what I think Chignecto Woodsman is trying to say too, if I understand him correctly.

Look at the picture you have posted:

The direction of a straight stick/handle in the same wrist position and grip would be in the line A, not B.

The actual pivot you are transmitting to the handle is actually that determined by your grip at the contact.

The effective final pivot experienced by the axe head is affected in addition by the form of the handle too.

Once again, think Flex Screwdriver.

So regarding the actual pivot axis of the axe head the pivot axis of your forearm is not so important (it is the rotational axis of the handle of the flex screwdriver in my analogy).

Now, on what we agree:

The downward curve of a curved axe handle allows the wrist to be tilted less to achieve a hold in which the rotational axis of the axe head to be more in line with the rotational axis of the forearm.

From this point on we disagree again:

Due to the natural movements of the wrist (carpus), palm (metacarpus) and the fingers during an actual swing and at the impact of strike the highly flexible wrist coupled with relatively weak stabilizing muscles results in an unavoidable and difficult to control deviation from the angles maintained during the static hold you show on your picture. This means, that the wrist position advantages seen during of a static grip of a curved axe handle are not necessarily translated to an actual advantage during the dynamics of striking.

The downward curve of most curved axe handles results in actually more wrist effort to control the axe head’s position toward the end of the strike, when your other hand has slipped back close to the one you are gripping the end of the handle, and both wrists are trying to stabilize and direct the movement of the axe bit.

So I think that the advantages regarding wrist position and effort provided at a static hold of a curved handle at the beginning of an axe strike can be quickly negated by the wrist strain necessary for control at the end of the strike.