Evener to single tree adjustable attachment

[jwayne972]

Mike,
Carl can correct me if I’m wrong, but I will express the deductions I have made as to the construction. The half inch in post 13 is just the surface of the pipe that does not come in contact with the pole, optical illusion. The tab is 1/2 inch thick to match the rod, the main pipe is 1/8″ walled and when smashed flat a 1/8″ plate is welded on top and bottom to equal 1/2″. Well that’s how I’m going to do it 😀 Just what I needed, another project:rolleyes:

[Carl Russell]

Mike Rock;23571 wrote:

Carl,
A question on construction. In the photo in post #13, what is in the first 1/2″ of the tape? Is that a piece of 1/2″ round to the front of the rod? Also, is the round main member rod or pipe?

In photos 2 and 3 of post #12 we have a lot of parts coming together. It looks like the tab with the five holes , the end of the rod/pipe and the triangular reinforcement and the 1/2″ rod on the rear wraps around the end tab as far as the rear of the tab. How thick is the tab with the five holes? The devil is in the details. This looks great and sure balances the horses.

Thanks,
Mike Rock

That is just an optical illusion… it is just 1 1/2″ pipe.

The flat steel is probably 1/2″

Carl

[OldKat]

Carl,

I am logged in (obviously), but I can’t see the picture you posted in this thread. I don’t see anything other than the text of the thread. Any idea what I can do to be able to see what you guys are talking about?

Thanks …

[CharlyBonifaz]

@Biological Woodsman 23564 wrote:

I had always thought that the horse that was behind was in the hole and had more of the load just because they were closer to the resistance or load. It seems the horse that is behind has a hard time bringing their side back to even. I guess I was just reading the horses more than the physics or engineering, because it seems that horses that are hooked heavy seem to want to be out front, which made me think it was easier than being behind.

does this picture explain it a little? in the end it depends on where you have your holes in the evener: are they in a straight line or is the middle one set back or up front….assuming the off horse in draft direction steps up

[Carl Russell]

OldKat;23575 wrote:

Carl,

I am logged in (obviously), but I can’t see the picture you posted in this thread. I don’t see anything other than the text of the thread. Any idea what I can do to be able to see what you guys are talking about?

Thanks …

I have heard similar remarks from folks using phones, etc.

I am at a loss really…. I don’t understand a lot of these things.

From time to time I have problems with formatting and interfacing on-line…. the only thing I have found that works is to restart the computer, and sometimes turn off the web server for a short interval….

Other than that, I’m sorry for the inconvenience, Carl

BTW… Excellent drawings Elke, thanks….

[Tim Harrigan]

@Biological Woodsman 23564 wrote:

A question I always wanted to ask Tim is if he thought a buffer would add to the capacity of a pulling team? If so, I want one…
Jason

Based on the measurements we have made it is clear that a buffer can change the nature of the pulling force, but it is not clear to me yet that it can add to the capacity in a practical way. I suspect that it is possible to design a buffer to do that for a task that is predictable as far as the speed and pulling force needed but not so easy to do over a wide range of tasks and pulling forces. For instance, we compared wagon draft with horses using standard traces or a type of nylon rope trace (ZEP). When we pulled a wagon with pneumatic tires the average draft was 19% higher with the standard traces than with the nylon rope. When we used the same harness systems with a wagon with the same load with steel tires which of course pulled much harder there was no advantage for the nylon rope trace.

So I think it is possible, not sure how practical it is. Andy designed a nice singletree that we will be testing in the near future as soon as I can get some final details worked out. We will be discussing it on DAPnet for sure when we do.

[near horse]

@Carl Russell 23578 wrote:

…..I am at a loss really…. I don’t understand a lot of these things…..

Ha, Carl, you expressed my thoughts with regard to this evener discussion:eek:

So my question is 1) are we talking about changing the moment arm (lever arm) length by changing the point at which the singletree attaches to the evener (move it wider on the weaker horse)? OR, and this is where I’m mixed up 2) are we saying something about changing the moment arm during the pull by some means that I can’t seem to understand. I’ll leave it at that I guess.

Also, can moving the attachment point of the singletree out ward 1/2 to 1 inch really make that much diffference in shifting the load carried by each horse? I see that it changes things from 50:50 to 53:47 but is that enough to see a difference in performance? (I imagine the answer must be yes or else we wouldn’t see this type of unit).

I

[jac]

So if a horse gets “behind” on the evener.. how much extra effort does he need to put in to catch up ?? because if he is behind does that not have the effect of shortening his side and will this not have the effect of making the weaker horse have an even bigger disadvantage:confused:…think I’ll just join the confused line:D..
John

[CharlyBonifaz]

So if a horse gets “behind” on the evener.. how much extra effort does he need to put in to catch up ??

don’t know 😀
but
from my understanding the deal should be to prevent the getting behind of the weaker / untrained horse; so actually I have to look ahead and figure out my needs in advance
does that make sense?
if you talk about the difference of length of the lever arms, shouldn’t that equal the difference in weights of the animals first of all?
Carl’s evener is built with the hole to hook towards the load behind the ones on each end of the evener, that means it will actually be easier on the horse that lags behind to use its power

[Andy Carson]

Carl’s doubletree is 42 inches between the two singletree attachment points and the hitchpoint is set back about 4 inches. This means the distance between the hitchpoint and the singletree attachment points is 21.38 inches (from a*a+b*b=c*c or 21*21+4*4=c*c). As this distance will not change no matter how the horses are layed out, it can be used to calculate the load that each team member is pulling when one moves ahead of another.

With the horses even, each lever arm is 21 inches long. If the team is pulling 600 lbs, it’s distributed with each horse pulling 300 lbs.

If one horse moves ahead 4 inches, this causes the lever arm on the backward horse to lengthen to a straight line between the hitch point and the singletree attachment point. The distance of the lever arm here becomes equal to the hypotenuse or 21.38 inches. The lever arm on the forward horse reduces to 19.81 inches (a*a+8*8=21.38*21.38). If the team is pulling 600 lbs, it’s now distributed with the forward horse pulling 311 lbs, and the trailing horse pulling 289.

If one horse moves ahead 8 inches, this causes the lever arm on the backward horse to reduce. The distance of the lever arm on the trailing horse here can be calculated by (a*a+4*4=21.38*21.38) or 21 inches. The lever arm on the forward horse reduces to 17.69 inches (a^2+12*12=21.38*21.38). If the team is pulling 600 lbs, it’s now distributed with the forward horse pulling 326 lbs, and the backward horse pulling 274.

If one horse moves ahead 12 inches, this causes the lever arm on the backward horse to reduce even further. The distance of the lever arm on the trailing horse here can be calculated by (a*a+8*8=21.38*21.38) or 19.83 inches. The lever arm on the forward horse reduces to 14.18 inches (a*a+16*16=21.38*21.38). If the team is pulling 600 lbs, it’s now distributed with the forward horse pulling 350 lbs, and the backward horse pulling 250.

If one horse moves ahead 16 inches (if this is even possible), both lever arms reduce in length dramatically. The distance of the lever arm on the trailing horse here can be calculated by (a*a+12*12=21.38*21.38) or 17.69 inches. The lever arm on the forward horse reduces to 7.56 inches (a*a+20*20=21.38*21.38). If the team is pulling 600 lbs, it’s now distributed with the forward horse pulling 420 lbs, and the backward horse pulling only 180.

So, with the pulling geometry set up like this, a single horse could be asked to pull anywhere from 180 pounds to 420 pounds depending on their position relative to their teammate. It’s a pretty big effect, and the forward horse is pulling substantially harder.

[Carl Russell]

near horse;23625 wrote:

…. 1) are we talking about changing the moment arm (lever arm) length by changing the point at which the singletree attaches to the evener (move it wider on the weaker horse)? OR, and this is where I’m mixed up.

This is the gross adjustment. This allows the teamster to shift the load onto the more powerful animal, or more accurately to move the horse closer to the load…. think see-saw. It really takes very little change in the length of the lever to deliver advantage.

2) are we saying something about changing the moment arm during the pull by some means that I can’t seem to understand. I’ll leave it at that I guess.

Because the evener is triangle shaped, when one horse moves forward the center of pull between the two moves toward the slower horse, this in essence shortens the lever for the faster horse, moving them closer to the load, and lengthens the lever for the slower horse, moving them away from the load.

So if I have a fast, strong, or fast and strong horse, I move them in one hole to see how much advantage that gives to the other horse. The strong horse is at a disadvantage to start, then if they surge ahead they have even more of the load. If this setting is not enough to help the slower horse I move her in another hole. And so on…. (OMG I just got a Vonnegut flash-back)

I think the long evener has been a design for a long time. Even when set even, the slower horse, or the horse that got stubbed, can recover with less exertion. In other words it is not so much to shift the load to the fast horse as it is designed to reduce the load on the horse that needs to catch up.

Carl

[Carl Russell]

Countymouse;23639 wrote:

…..
With the horses even, each lever arm is 21 inches long. If the team is pulling 600 lbs, it’s distributed with each horse pulling 300 lbs.

If one horse moves ahead 4 inches, this causes the lever arm on the backward horse to lengthen to ….. 21.38 inches. The lever arm on the forward horse reduces to 19.81 inches …. it’s now distributed with the forward horse pulling 311 lbs, and the trailing horse pulling 289.

…. ahead 8 inches, this causes the lever arm on the backward horse to reduce….. 21 inches. The lever arm on the forward horse reduces to 17.69 inches ….. it’s now distributed with the forward horse pulling 326 lbs, and the backward horse pulling 274.
…

… 12 inches, this causes the lever arm on the backward horse to reduce even further…. 19.83 inches. The lever arm on the forward horse reduces to 14.18 inches ….forward horse pulling 350 lbs, and the backward horse pulling 250.

….

Thanks Andy…. with these numbers it can be seen that not only is the load less on the slower horse, but as that horse begins to recover it is moving into greater advantage relative to the load, although the weight is increasing, because the length of his side of the evener gets longer as he moves up on the other horse.

Carl

[Andy Carson]

It is very interesting the numbers came out like this, and I can think of a number of interesting implications. I had (like Geoff) expected the differences to be not as dramatic. i can see now why only small (relatively) adjustments are needed to distribute loads between stronger and weaker horses. The evener does a lot to distribute the load over which ever horse can carry it. It probably ought to be called a “distributor” rather than an “evener.” 🙂

[Tim Harrigan]

Thanks for working that out, Andy. It is quite interesting how subtle differences in pin placement allow quite a large range in fine-tuning in distributing the pulling forces to the team. The differences could be accentuated (not with this evener, but in designing another) by dropping the center pin back an inch or so, or perhaps by allowing a little lateral adjustment in the center pin placement. As I mentioned earlier, moving the center pin 1 inch side-to-side has the same effect as moving an end pin 2 inches. Good stuff, and these historical designs were no accident.

[Mark Cowdrey]

Andy,
Thanks, great and to me stunning information that of course makes me think of other questions.

What effect, if any, does the overall length of the evener have in terms of advantage to the horses? Assuming to start that both horses are “equal”, that the evener is perpendicular to the load, is the length of each side of the evener (lever arm) significant? Intuitively I’m thinking no, the load is still the load split in half, but…

There is a SFJ article in this thread that would be valuable to the greater community.

Mark

[Author]

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