Who else uses a scythe?

[Steve Tall]

...I'd guess that it's late 19th century at the [earliest], more likely later....

I agree. I should have said 19th century at the earliest.

 

[BG_Farmer]

[/URL][/IMG]

[/URL][/IMG]

[/URL][/IMG]

18th C scythe. Handholds may be later. The blade has crack. I think the writing on blade indicates this was part of an early collection, a museum acquisition number possibly. I don't know much about these. Any thoughts would be appreciated.

I agree with 42B and ST on the blade, late 19th to mid 20th century. The nibs are later, as 42 said, and I think they would work better on the other side of that snath, as straight as it is, or maybe the blade is turned around? One reservation I have is that the snath shaft and collar are basically un date able, as the variety of homemade and/or locally produced implementations is pretty much infinite. On the shaft, the only distinctive characteristic is the round to square, which is a little on the fancy side for homemade, but I have a hard time shaking the impression that it closely resembles one handle for a post hole digger that has been repurposed. That is one of the things I like about scythes: they can be as simple or as complex as possible and made to work pretty well if the user knows what to adjust and how he wants it to work...

 

[FortyTwoBlades]

I agree with 42B and ST on the blade, late 19th to mid 20th century. The nibs are later, as 42 said, and I think they would work better on the other side of that snath, as straight as it is, or maybe the blade is turned around? One reservation I have is that the snath shaft and collar are basically un date able, as the variety of homemade and/or locally produced implementations is pretty much infinite. On the shaft, the only distinctive characteristic is the round to square, which is a little on the fancy side for homemade, but I have a hard time shaking the impression that it closely resembles one handle for a post hole digger that has been repurposed. That is one of the things I like about scythes: they can be as simple or as complex as possible and made to work pretty well if the user knows what to adjust and how he wants it to work...

Nibs are best used facing forward, as the shaft of the snath is often used as a component of the grip.

 

[Bladite]

A Canadian boy named Ti-Jean saves the day (with a scythe) when the combine breaks down.

(starting at 13:45)

[video=youtube_share;28hS0y-yqdw]http://youtu.be/28hS0y-yqdw?t=13m40s[/video]

https://www.youtube.com/watch?feature=player_detailpage&v=28hS0y-yqdw#t=820

hysterical. esp given the scythe he uses

he leaves his hobo bag at the station

uses the wrong scythe

apparently has the luck to have a scythe in the truck, and a stone!

 

[BG_Farmer]

Nibs are best used facing forward, as the shaft of the snath is often used as a component of the grip.

Agreed with a curved snath, but this one is straight and it seems most of the European scythes have the nibs (often on risers or in case of some, drops) on the other side to compensate for lack of lateral bend.

 

[FortyTwoBlades]

Agreed with a curved snath, but this one is straight and it seems most of the European scythes have the nibs (often on risers or in case of some, drops) on the other side to compensate for lack of lateral bend.

Yes, a stemmed grip for either the right hand (raised) or the left hand (dropped) is typical with straight snaths unless they're a single-grip. However, in those cases a more contoured shape to the grips is preferable since they can't exploit the shaft of the snath as a grip component. Rear-facing nibs wouldn't work so hot. The nibs on this are a less than ideal arrangement.

 

[Steve Tall]

Nibs are best used facing forward, as the shaft of the snath is often used as a component of the grip.

Photo from ScytheConnection.com


In my opinion, a well-shaped grip that fills the hand, whether it faces forward or rearward, is preferable to simultaneously gripping a round "peg" and the round shaft to which it's attached at a 90 degree angle.

 

[FortyTwoBlades]

In my opinion, a well-shaped grip that fills the hand, whether it faces forward or rearward, is preferable to simultaneously gripping a round "peg" and the round shaft to which it's attached at a 90 degree angle.

It's actually quite comfortable, and there are numerous ways of gripping it, of which this is just one. I don't ever find my hands complaining, personally, and I'm able to alter my grip to change the presentation of the blade a bit so I can work slightly different muscle groups at different levels of engagement over the course of the mowing session while taking swaths of equal dimension (particularly useful when cutting very dense neglected areas full of woody stuff.) It can certainly be held in manners that are unergonomic, but in the modern age we all-too-frequently think of a grip as a single isolated component when there were many tools historically where the concept of the grippable region of a tool was much looser. Many historical swords, for instance, incorporated the pommel, ricasso, and guard into the region that was intended to be gripped in use.

The hands, in the photo I posted, are only used to hold a consistent position and control rotation/presentation while the heel of the palm is actually bearing the greater amount of the force in use, with a pulling action. You can modulate how much you want to use the grasp of the hands vs. how much pressure from the palms, but I use more from the palms than from the fingers. It's a very relaxed hold. The nib can also be used as a stop of sorts for adjusting your rotation (and consequently the radius of your stoke.)

 

[FortyTwoBlades]

Also worthy of note is the difference in design parameters for a grip that is meant to be pushed vs. one meant to be pulled. A grip meant to be pushed will be transferring the force into the palm, while a grip that is pulled most commonly will want to transfer that energy into the fingers. A drawing action will be the more efficient motion in mowing because of the lever types we're dealing with (first class for pulling vs. third class for pushing) but having the force transferred to the fingers would grow tiring even with otherwise sound ergonomics. The use of the shaft of the snath as a brace allows the resistance during the drawing stroke to be born by the palm instead of the fingers.

 

[Steve Tall]

Also worthy of note is the difference in design parameters for a grip that is meant to be pushed vs. one meant to be pulled. A grip meant to be pushed will be transferring the force into the palm, while a grip that is pulled most commonly will want to transfer that energy into the fingers. A drawing action will be the more efficient motion in mowing because of the lever types we're dealing with (first class for pulling vs. third class for pushing) but having the force transferred to the fingers would grow tiring even with otherwise sound ergonomics. The use of the shaft of the snath as a brace allows the resistance during the drawing stroke to be born by the palm instead of the fingers.

Sounds like pushing is the desired outcome, and since those round nibs themselves cannot be effectively pushed with the palms, the hand is moved back to push the palm against the shaft of the snath.

 

[FortyTwoBlades]

Sounds like pushing is the desired outcome, and since those round nibs themselves cannot be effectively pushed with the palms, the hand is moved back to push the palm against the shaft of the snath.

No, not really. Pushing is more ideal when it comes to transmitting force into the skeletal system, but in the context of scything using a drawing action to commit the stroke is much more advantageous overall. For the same lengths, a third class lever is a good deal less efficient at moving a load. Say you have a snath with the lower grip set 30.5" from the end and the upper grip set another 20.5" up from that. Using a first class lever (drawing the left hand with the right acting as a pivot) you have a mechanical (dis)advantage of 0.67, but if using a third class lever (pushing the right hand with the left hand as the pivot) your mechanical advantage drops to a pitiful 0.40 -- that's a 40% decrease! As another way of looking at it, the drawing method is 1.675 times as effective at translating your force into moving the load on the end of the snath. Meanwhile, on a strict basis of comparing blade weights in that context, let's see what the difference would mean...

A Falci #106 (their most popular blade, or so I've heard) in 75cm (≈29.5") length weighs 473g (≈1.33lb) while a Seymour 30" grass blade weighs 1.69lb. The Falci blade is 0.36lb lighter, which is only about a 21.3% weight savings. If mounted on the same snath but the Seymour blade swung using a drawing stroke and the Falci swung using a pushing stroke, the fellow using the heavier Seymour would actually be exerting less force to make his stroke than the fellow with the lighter Falci blade!

Now, fortunately, it is possible to use that same Falci blade with a drawing stroke instead of a pushing one, and indeed, a snath with a right-handed stem is, as far as stemmed types go, the best arrangement to have for cutting on the pull. However, the grips should be so formed as to minimize direct transfer of energy into the fingers.

 

[Steve Tall]

No, not really. Pushing is more ideal when it comes to transmitting force into the skeletal system, but in the context of scything using a drawing action to commit the stroke is much more advantageous overall. For the same lengths, a third class lever is a good deal less efficient at moving a load. Say you have a snath with the lower grip set 30.5" from the end and the upper grip set another 20.5" up from that. Using a first class lever (drawing the left hand with the right acting as a pivot) you have a mechanical (dis)advantage of 0.67, but if using a third class lever (pushing the right hand with the left hand as the pivot) your mechanical advantage drops to a pitiful 0.40 -- that's a 40% decrease! As another way of looking at it, the drawing method is 1.675 times as effective at translating your force into moving the load on the end of the snath. Meanwhile, on a strict basis of comparing blade weights in that context, let's see what the difference would mean...

A Falci #106 (their most popular blade, or so I've heard) in 75cm (≈29.5") length weighs 473g (≈1.33lb) while a Seymour 30" grass blade weighs 1.69lb. The Falci blade is 0.36lb lighter, which is only about a 21.3% weight savings. If mounted on the same snath but the Seymour blade swung using a drawing stroke and the Falci swung using a pushing stroke, the fellow using the heavier Seymour would actually be using less energy than the fellow with the lighter Falci blade!

Now, fortunately, it is possible to use that same Falci blade with a drawing stroke instead of a pushing one, and indeed, a snath with a right-handed stem is, as far as stemmed types go, the best arrangement to have for cutting on the pull. However, the grips should be so formed as to minimize direct transfer of energy into the fingers.

What I said is actually true, regarding pressing with the palm (forget "pushing" or "pulling") instead of accomplishing the same force using the bent fingers.

With these leverage explanations and examples, I think that you are mistakenly disregarding the required force exerted by the other hand on what is being called the "pivot". It's not the same biomechanics as using a lever with the pivot (or fulcrum) attached to something immoveable.

 

[FortyTwoBlades]

What I said is actually true, regarding pressing with the palm (forget "pushing" or "pulling") instead of accomplishing the same force using the bent fingers.

With these leverage explanations and examples, I think that you are mistakenly disregarding the required force exerted by the other hand on what is being called the "pivot". It's not the same biomechanics as using a lever with the pivot (or fulcrum) attached to something immoveable.

When I said "no--not quite" I meant it in regards to pushing being the ideal arrangement. Pulling strokes afford greater mechanical advantage.

The strokes being used were the extremes of only the left hand or right hand engaged in the motion. You can use a combination of the two, lessening the force applied on the one system and expending it on the other, but the more you push from the right hand and the less you pull with the left, the greater the energy it's going to require for you to make the same stroke. It's quite handy to alter the amount of push vs. pull, however, in order to affect the radius of your stroke, and therefore the dimensions of your swath, without having to stop and adjust the hang to produce the effect. This is good for shorter term alterations when you encounter variations in the growth vs. adjusting the hang, as adjusting the hang to best match the dominant conditions will allow you to use the most efficient stroke through the bulk of your work.

If you are applying force from both hands then your left hand is responsible for a certain amount of the work, performed under the function of a first class lever, while the right hand is responsible for the rest of the work, being performed using a third class lever. But if both hands exert equal force, the left hand will have been responsible for moving the blade the larger portion of its total travel.

 

[Steve Tall]

...Say you have a snath with the lower grip set 30.5" from the end and the upper grip set another 20.5" up from that. Using a first class lever (drawing the left hand with the right acting as a pivot) you have a mechanical (dis)advantage of 0.67, but if using a third class lever (pushing the right hand with the left hand as the pivot) your mechanical advantage drops to a pitiful 0.40 -- that's a 40% decrease! As another way of looking at it, the drawing method is 1.675 times as effective at translating your force into moving the load on the end of the snath...

...If mounted on the same snath but the Seymour blade swung using a drawing stroke and the Falci swung using a pushing stroke, the fellow using the heavier Seymour would actually be exerting less force to make his stroke than the fellow with the lighter Falci blade!
...

These examples are incorrect because they are considering only the force exerted by one hand while the scythe is being used. There will actually be forces imparted by both hands, and they both need to be considered. Those calculations are incorrect for this case because the fulcrum or pivot will also require force from the body.

...The strokes being used were the extremes of only the left hand or right hand engaged in the motion. You can use a combination of the two, lessening the force applied on the one system and expending it on the other, but the more you push from the right hand and the less you pull with the left, the greater the energy it's going to require for you to make the same stroke...

It's impossible to use a scythe unless both hands are applying force. I'm thinking the forces on both hands would be significant, but the effect on the body depends on the muscles that are being loaded (e.g. biceps vs. triceps...)

...
If you are applying force from both hands then your left hand is responsible for a certain amount of the work, performed under the function of a first class lever, while the right hand is responsible for the rest of the work, being performed using a third class lever. But if both hands exert equal force, the left hand will have been responsible for moving the blade the larger portion of its total travel.

There will always be forces being applied by both hands when the scythe is swung. I think that the question of which hand moves more will largely affect which muscles are being used more, which hasn't been addressed.

 

[FortyTwoBlades]

These examples are incorrect because they are considering only the force exerted by one hand while the scythe is being used. There will actually be forces imparted by both hands, and they both need to be considered. Those calculations are incorrect for this case because the fulcrum or pivot will also require force from the body.




It's impossible to use a scythe unless both hands are applying force. I'm thinking the forces on both hands would be significant, but the effect on the body depends on the muscles that are being loaded (e.g. biceps vs. triceps...)



There will always be forces being applied by both hands when the scythe is swung. I think that the question of which hand moves more will largely affect which muscles are being used more, which hasn't been addressed.

True, both hands will nearly always be in motion, but you're confusing force applied to move the scythe laterally vs. force used to actually rotate the scythe. Those are different forces performed at the same time, and the forces applied to move the scythe laterally do not have an effect on the amount of force required to rotate the scythe relative to the hands. This is not the total motion of a typical stroke, as most strokes will employ both rotational and lateral motion from the arms and shoulders, rotation of the torso/hips, and a lateral shift of the hips/legs. None of these impact a direct comparison of the rotational forces imparted by the arms--we're talking about that in isolation.

Think of it this way--your goal is to move the scythe blade a mere 2ft along an arc--any arc at all, but 2ft of travel. You have numerous ways of engaging your muscle groups to do this, and any combination of motions of your body contribute a percentage of the motion. If you were to then take all of those motions and divide them up in isolation to see their actual input to the total work done, you might have moved the blade 6" with one motion, 8" with another, etc. but the total result of those efforts is a blade travel of 2ft. So in this case we are looking strictly at the effects of rotational contribution of the arms, which would be added to the rest of the motions of the body to describe the specific arc generated by the user's stroke.

 

[Steve Tall]

True, both hands will nearly always be in motion, but you're confusing force applied to move the scythe laterally vs. force used to actually rotate the scythe....So in this case we are looking strictly at the effects of rotational contribution of the arms...

I've only been talking about the forces to rotate the scythe, so no confusion there.

Maybe these drawings will help me be more clear. This type of drawing is the basis for your calculations and comments on leverage and advantage:

The trouble is, this type of drawing usually leaves out the forces acting on the pivots. But the forces are still there. Replace the "pivot" with "effort" from another hand on the lever, and you have a tool like a shovel or a scythe.

Check out the forces being applied to the shovel below:

Both the left and right hands are applying force to the shovel. Either hand can act as the pivot of the previous drawing, and this won't change the forces. The end hand will still be applying the same downward force that's shown, and the middle hand will still be applying the same upward force that's shown. The force applied by the hand in the middle will be equal to the sum of the weight in the shovel, plus the force applied by the end hand.

Change the shovel into a scythe, and the force applied by the hand in the middle will be opposite in direction, and equal in magnitude, to the sum of the force applied by the hand on the end, plus the load force from the blade.


I'm hoping that this will clarify my previous comments.

 

[FortyTwoBlades]

I've only been talking about the forces to rotate the scythe, so no confusion there.

Maybe these drawings will help me be more clear. This type of drawing is the basis for your calculations and comments on leverage and advantage:

The trouble is, this type of drawing usually leaves out the forces acting on the pivots. But the forces are still there. Replace the "pivot" with "effort" from another hand on the lever, and you have a tool like a shovel or a scythe.

Check out the forces being applied to the shovel below:

Both the left and right hands are applying force to the shovel. Either hand can act as the pivot of the previous drawing, and this won't change the forces. The end hand will still be applying the same downward force that's shown, and the middle hand will still be applying the same upward force that's shown. The force applied by the hand in the middle will be equal to the sum of the weight in the shovel, plus the force applied by the end hand.

Change the shovel into a scythe, and the force applied by the hand in the middle will be opposite in direction, and equal in magnitude, to the sum of the force applied by the hand on the end, plus the load force from the blade.


I'm hoping that this will clarify my previous comments.

The problem with comparing it to a wheel barrow or shovel is that the blade, which comprises the load, is resting on the ground and so gravitational forces aren't coming into play in terms of the leverage used to rotate the tool. The diagrams you show are for forces in vertical opposition while the scythe is in horizontal opposition and as such does not need to fight gravity save for its contribution to frictional forces or the minimal load of holding up the snath.

Likewise the force required to hold a free body in equilibrium are not the same as the forces required to move it. If I wanted to hold the shovel load easier I'd be moving my lower hand (the fulcrum) closer to the neck to minimize leverage forces on my body. Once lifted, not only will I have an easier time holding that load, but manipulating the angulation of the shovel blade will be easier on account of the extended lever arm for my upper hand, though my total range of manipulation will be less. You can feel this easily if you just go out and grab a shovel and try it. Scoop up a load of either dirt or snow (depending on how things are in your neck of the woods) and see the difference in experienced strain between holding the shovel handle at its midpoint vs. at the neck, and the difference in the motion you are able to create with the end of the handle in accordance to wear your lower hand is and the strain imparted on the body.

 

[Steve Tall]

The problem with comparing it to a wheel barrow or shovel is that the blade, which comprises the load, is resting on the ground and so gravitational forces aren't coming into play in terms of the leverage used to rotate the tool. The diagrams you show are for forces in vertical opposition while the scythe is in horizontal opposition and as such does not need to fight gravity save for its contribution to frictional forces or the minimal load of holding up the snath.

If you have a certain force being applied to the end of a shovel, it doesn't matter whether it's caused by gravity or caused by a guy pulling on a rope (for example), the forces and leverage calculations stay the same.

Likewise, it doesn't matter about "vertical opposition" or "horizontal opposition", the planes can be switched and the forces and leverage calculations stay the same. The effects of gravity, if considered, can be reduced to another force applied to the tool handle. The shovel diagram does apply to the scythe example, since in both cases the forces are just acting in one plane.

Likewise the force required to hold a free body in equilibrium are not the same as the forces required to move it.

That's right, the dynamic situation gets complicated, depending on the effects of accelerations, etc. However, it takes just a slight increase in forces, above the equilibrium forces, to move the shovel (or scythe). Your initial calculations of leverage and discussion of forces were simplified enough that the static loading diagrams are enough to show what you are leaving out of the picture.

...If I wanted to hold the shovel load easier I'd be moving my lower hand (the fulcrum) closer to the neck to minimize leverage forces on my body. Once lifted, not only will I have an easier time holding that load, but manipulating the angulation of the shovel blade will be easier on account of the extended lever arm for my upper hand, though my total range of manipulation will be less. You can feel this easily if you just go out and grab a shovel and try it. Scoop up a load of either dirt or snow (depending on how things are in your neck of the woods) and see the difference in experienced strain between holding the shovel handle at its midpoint vs. at the neck, and the difference in the motion you are able to create with the end of the handle in accordance to wear your lower hand is and the strain imparted on the body.

Yes, I already know how leverage works. Really.

When you lift the shovel (or swing a scythe), both hands need to be applying force to the handle, regardless of which (if any) hand you are pivoting around. You cannot have "only the left hand or right hand engaged in the motion", as claimed.

 

[FortyTwoBlades]

If you have a certain force being applied to the end of a shovel, it doesn't matter whether it's caused by gravity or caused by a guy pulling on a rope (for example), the forces and leverage calculations stay the same.

Likewise, it doesn't matter about "vertical opposition" or "horizontal opposition", the planes can be switched and the forces and leverage calculations stay the same. The effects of gravity, if considered, can be reduced to another force applied to the tool handle. The shovel diagram does apply to the scythe example, since in both cases the forces are just acting in one plane.


That's right, the dynamic situation gets complicated, depending on the effects of accelerations, etc. However, it takes just a slight increase in forces, above the equilibrium forces, to move the shovel (or scythe). Your initial calculations of leverage and discussion of forces were simplified enough that the static loading diagrams are enough to show what you are leaving out of the picture.


Yes, I already know how leverage works. Really.

When you lift the shovel (or swing a scythe), I hope it's now clear that both hands need to be applying force to the handle, regardless of which (if any) hand you are pivoting around. You cannot have "only the left hand or right hand engaged in the motion", as claimed.

No, it is possible to have just one hand or the other engaged in the action of actually moving the scythe. It just makes for a very short stroke, with the pushing stroke taking the longer of the two. It's true that there's some degree of oppositional pressure applied to the other hand, but it's very small compared to the force translated to the blade end of the snath.

The longer travel of the pulling stroke results in a greater force exerted on the scythe blade while reducing effort required, while the third class lever requires higher effort and shorter distance. The same energy is required to move the load in either case, but the first class lever uses less force over a longer distance. In terms of torque (force x radial distance) the first class lever is increasing the radial distance and so reduces the force necessary to move the blade while the third class is reducing the radial length and increasing the force required.

The shovel is not a good analog because it's demonstrating leverage imparted on the body by lifting the load, whereas in this case we are trying to rotate the load over a distance. We're looking to complete a fixed amount of rotation with a fixed amount of load, but with the least force requirement possible. Given the constraints of biometrics, there is a limit to how much we can extend our lever arm relative to the pivot, since the point of pivot must exist somewhere between the hands. Therefore, the greatest mechanical advantage is afforded by moving the left hand and the right hand acting as a floating pivot, which also has the effect of shortening the radius of the load from the fulcrum. Under the third class example you will have very rapid acceleration because of the longer radius of the stroke, but it will require more effort in order to complete that stroke.

This all also has an effect on how much vegetation we can conceivably cut, because of the limits of human strength. As the stroke gathers the cut grass for deposition into the windrow, the load is increasing. The larger the radius you take, the lower the weight of vegetable mass per unit of travel needs to be taken so you don't reach your threshold before the end of the stroke. As such a larger radius and/or deeper swath are best taken when vegetation is short or light, and a larger radius in specific is best taken with very light vegetation that is more easily cut with a more accelerated stroke. It's effectively like shifting gears...how much velocity are you getting vs. how much torque you're getting. More resistant materials will more easily be cut with greater torque while more flexible or slippery targets will be more easily cut with velocity.

 

[Steve Tall]

Oh, well. I tried.

Is there a mechanical engineer in the house
(who could weigh in on this) ?