[Andy Carson]

I am doing a summer fallow trying destroy weeds without burying thier seeds too deep. When the weeds are under control, I plan to plant a cover crops (probably oats and peas) for next year. I am using a converted single gang disc (designed for a lawn tractor) it has a single gang of 8 12 inch diameter smooth discs, and is about 40 inches wide. I would estimate it weighs 75 pounds, but I sit on it, making the whole thing weigh almost 300 pounds. It is adjusted to maximum angle, but I would be guessing at what that angle is… It does a good job knocking down and uprooting weeds and grass when I make a pass in one direction and return with a pass in the opposite direction. The penetration is variable because the disc tends to roll over the corn stalks bringing them back to the surface. As far as draft, this seems a little light for my horse on some days, just right on others. I definately couldn’t double the draft and pull it for very long, but she could probably pull 25-50% more without trouble. I have about 4 of 5 acres disced, but broke a disc and thought it was a good time to reevaluate the technique…

[Andy Carson]

Maybe you could split her off with the second chubbiest horse (if you have another chubby one). Alternatively (or additionally) if you split her off with a dominant horse and supplement hay (in not too many places), the dominant horse would likely take more hay even things out. Just ideas…

[Andy Carson]

I have a combination halter/bridle that I have used for riding before. It is similar to the photo below. My horse doesn’t think she is working unless she has blinders on, and I haven’t felt like curing her of this as yet so this combo simply collects dust now. It is indeed very very handy for tying. Taking the bit in and out (at least with this design) is not as easy as it might first appear. It looks like you can attach one clip, swing the bit through the mouth and then attach the other clip. My horse (at least) detests this and insists the bit must be put in strait. It takes a little practice to be able to aim the bit into the mouth while holding onto both clips to attach the bit holders to the headpiece. I hook the ring ends over my pinkies while holding onto the clips with my thumbs and pionter fingers. That allows me to gently and precisely place the bit without having to regrab the clip ends. After I get the bit in, I let the bit holder straps (name?) slide between my pinkies and ring fingers while moving my hands up to clip in the straps. It sounds more complicated than it is… Once I got bit placement down, the setup was pretty slick.

[Andy Carson]

Although I never met him, I always admired Rudy from afar and enjoyed looking at his photos and hearing about the work you did with him. I am sorry for your loss.

[Andy Carson]

Mitch, I would guess that is a harmonic oscillation. I wouldn’t have thought you could hit a combination of pull speed, drag force, and spring constants that could produce a sound though. Very interesting. When I see harmonic oscilaltions, I get kinda nervous about what might happen next. Harmonics can amplify peak forces and cause behaviors that are strange and unexpected. I always think to the video I saw of a bridge that would swing wildly in response to a very specific wind speed (I can’t remember the name of this bridge)… At any rate, as a matter of practice I would try to avoid any combination of drag, speed, and spring constant that gets you into a harmonic. This was one of the reasons I liked the friction on draft buffer II. I have to say though, the friction seems to dampen the responsiveness enough that I think it’s better off with a shackle.

Carl, I am glad you had a chance to see the buffer in action. It probably would work best with a more predictable load such as a log on smooth grass. That’s not to say it wouldn’t do anything on less predictable surfaces, but it might be really hard to see the action. One of the things that I found fascinating was watching the action of the spring while also watching the action of the horse. This way, you could really see which magnitude and duration of the forces generated during different parts of the stride. I am very curious what types of things were said about the buffer when you showed it. This may help me design a presentation that answers common questions and (especially) to design a better “buffer III.”

[Andy Carson]

Is jealousy welcome? I wish my horse was as easy of a keeper… My wifes riding horse is a really easy keeper too and he stays in a sacrifice area (an small overgrazed area) from feeding time (maybe 6 PM) until 10 PM or so, when we open the gate to the good pasture. That way, he gets 4 hours less grazing time than my horse. I can’t say that he has lost any weight, but at least he hasn’t put any more on. As far as heat, I give my horse a neck and belly clip in the spring and early summer and it seems to really help. I got the idea from riding horse clips, but I designed a slightly different pattern so the hair is on everywhere the harness might rub (except the base of the neck). A hairless belly, especially, really seems to help keep her cool.

[Andy Carson]

Personally, I relate to mares better, but everyone has thier own preferances and I don’t think one sex is better. You see mostly geldings at pulling contests. There was discussion about this topic on an older post: http://www.draftanimalpower.com/showthread.php?t=2843

[Andy Carson]

Is there a secure place to tie him if you unhitch? Maybe there is a tree nearby that you could hang a haynet from? Maybe even a couple trees to make a picketline from… i don’t know what your location is like, but four hours seems like a long time to just hang out. I know my horse would get restless too.

[Andy Carson]

@jac 19196 wrote:

Just looking at Carls fotos there…Is there any reason why the leaf spring has to be mounted in angle iron ?. Could the smaller helper spring not be put on the inside of the curve and the spring turned so its curve is around the horse so to speak with a shackle on each eye to take the heel chains and the pulling hook round the other way.. no friction that way and lighter ?….
John

John, that is a good idea. I had origionally looked into the design you are describing, but decided against it because I was worried about what might happen if the single tree was overloaded. In the design I made, the spring would decompress completely if overloaded and “bottom out” on the angle iron. At this point, the buffer would act like a standard singletree. Having something for the spring to “bottom out” on prevents overbending of the spring and the angle iron acts as a safety feature in that if the sprign breaks entirely, the singletree is still intact. Now that you bring the advantages of this system again, however, I think there is probably a way to incorporate this design aspect without compromising safety, perhaps by making a reinforced “bottom out bar.” I will play with some drawings. Thanks for the thought.

[Andy Carson]

Hmmm… 600-700 pounds is in the range that I would have expected to see a positive effect. I am also disturbed by the fact that you did not see any decompression of the spring and you are correct that this means the buffer is not working as designed. It is difficult to imagine how energy will be returned without spring decompression. As I think the draft forces are likely to fluctuate just as much in your hands as in mine, I am most likely to blame friction here. I suppose it’s also possible that my horse is less smooth than yours, but that’s part of why I wanted a second opinion. So, for improvements thus far:

1. Generally strengthen the singletree with bracing and tubing similar to a standard singletree

2. Make brackets to act as pivot points one the ends of the spring (so as to reduce friction and make buffer more responsive)

Any other thoughts?

PS. When you say the spring never recovered, do you mean it never decompressed at all or just never decompressed completely? A partial decompression while moving also indicates stored energy being returned to the system. With heavier loads, I never saw the spring completely decompress, it just fluctuated between different degrees on compression. This is still a good thing from a design point of view. Compressing and not moving, though, is pretty bad.

[Andy Carson]

Great pictures Carl, I was never able to make any action photos look that good. Too bad you don’t see much of a differance though… It might be hard to notice a differance with such variable terraign and loads, but I am curious if the loads might still be too light. If the buffer was working well, it would probably reduce loads by about 15% Do you think you would notice the differance between a 70 bf log and an 80 bf log? That is one of the reasons I ended up doing some testing with heavier loads on the sled, because I really do notice the differance between a 1000 lb load (for example) and a 1150 pound load. In other words, the heavier the load the easier it is to see differances between buffer and no buffer. On a sled it is easier to adjust the laod, though and I understand you kinda have to work with what nature gives you. I am not sure what a 70 bf log weighs or what the drag would be like. When the buffer is working at maximum capacity, the spring threatens to bottom out. If the spring is barely moving the load is still too light in my mind. Thanks again for all your thoughts on this, it is really helping me think about how to improve and strengthen the design.

[Andy Carson]

Carl, I wouldn’t worry about bending the single tree bending until the spring bottoms out. Besides, if it bends it’s easy to bend back. I would probably recommend a beefier one for logging in general, but this ought to show the concept… Actually, if you baby the buffer it is less likely to show any positive effect. The spring needs to be pulled hard enough that it compresses fairly often. That is probably a decent load even for a logger. I understand you hessitation with a new piece of equipement, but it was designed for a good working load and below that load the spring is likely to just sit there doing nothing. Besides, like I said, I can bend it back.

[Andy Carson]

Carl, are you saying it compressed the spring entirely, as in the spring bottomed out? I was a little worried about logging with it because of the heavy and variable loads involved, but thought I would see what you could notice anyway. I almost threw in the third leaf spring in case your loads bottomed it out, and am kicking myself for not doing that now. Longer term impovements in efficiency are probably only going to be noticable on longer duration work, but I also noticed an improvement in starting loads. I guess it was hard for you to say one way or the other with your twitching? I suppose it would be, as a fair comparison would really require twitching the same piece of woode over the same path twice, and is not really a very useful activity…

[Andy Carson]

That’s great! I am glad it was a good experience and if your horse is like mine they get over the new sights pretty fast. I have had good experiences on the road (I have to admit I don’t do it all that much anymore). I had expected some rude and impatient people and never met a single one. One issue I had was making left hand turns onto a busier road from a stop sign. During the turn, my horse and cart end up blocking both lanes of traffic for a short time, which prevents traffic from either direction from going around. I look to make sure it’s clear, but sometimes visibility is poor. On many corners, I ended up relying on my hearing as much as my eyes to tell when a car is coming. Try that in a car! Another potential trouble point is that if you really hug the curb, cars often try to pass whether there is room or not. I have seen at least one near head-on collision. So, in areas where passing is not safe (like around corners or when I can see there is oncoming traffic) I move out into the lane so no one can pass. Sometimes I turn around and make eye contact to let the driver know I see them and am not just spacing off. When it’s safe, I pull over to the right side of the lane and wave them by. At the beginning, I felt a little bit like a jerk by pulling out to where they can’t pass, but I haven’t had any complaints and it seems safer this way. My horse, by the way, looks really hard at large rocks on the side of the road but doesn’t care about cars, parked or not. I guess they all have thier quirks…

[Andy Carson]

I am planning on presenting the theory and practical applications of draft buffers at the 2010 NEAPFD. In thinking about how to best explain the concept, it has become clear to me that any amount of power stored in the spring (as represented by spring compression beyond the average draft) MUST be released back into the system. It seems obvious to me now, but really the power has no where else to go… Steel springs are incredibly resilient and the power will not simply be dissipated. Because releasing the stored energy produces positive work (pulls the load forward), then a properly designed draft buffer HAS to be producing a positive effect. That is, unless it is either 1. Not compressing over the average draft 2. Not decompressing 3. Produces harmonic oscillations resulting in slow fluctuations in velocity or 4. Dissipates stored energy. How much power is recovered and how much pracical impact this has on work are still open questions.

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