Main Discussion Area > Flight Bows
High gear/low gear
willie:
--- Quote ---No difference in limb bending but big difference in limb vibration
--- End quote ---
Marc, are you writing of limb vibration before or after the bow reaches brace upon release?
--- Quote ---If the design can maintain this for very light arrows without additional waves of limb distortion or vibration, then the light arrow efficiency will also be very high. There would also be little visible difference in post-shot vibration on the high speed video between the heavy and light arrow.
--- End quote ---
Alan, you seem to be specific about limb distortion (from the path along which it is drawn) occurring between FD and brace on the powerstroke. Has this been observed photographically? Toumo sees no difference in his two videos, but of course, that is one specific bow used with two different arrows.
Selfbowman:
I don't know about gears in a bow! But if a bow has shock wethere from bow vibration or string related it ant good. That robs cast! We all ways won't to see full draw pics? To prove even limbs. Well if the bow goes back to brace even it won't have much shock! If the limb tips are narrow as possible the less the shock. Reflex adds shock is what I have noticed. But it transfers more energy to a point. To much reflex adds to much mass which will add shock. I pay more attention to the shock in the bow.
Set is the other enemy! I think it comes down to design where the bow is light on the ends has little shock , limbs come to rest evenly , and have a good force draw. Then you have to match a good arrow that flys straight and true. I guess I am in agreement with Alan . Lol
Arvin
avcase:
--- Quote from: willie on April 01, 2019, 08:02:33 pm ---Alan, you seem to be specific about limb distortion (from the path along which it is drawn) occurring between FD and brace on the powerstroke. Has this been observed photographically? Toumo sees no difference in his two videos, but of course, that is one specific bow used with two different arrows.
--- End quote ---
I have not accurately measured these limb vibrations photographically. I can pretty clearly see the symptoms post shot and measured the effect on efficiency. If I were to do it photographically, then I would mark the side of the bow with about 20 dots from the center of the riser to one of the limb tips. I’d start with the bow braced, then track the limb as it is drawn. Then I’d need to have pretty clear high speed video, around 5000-10000 frames per second, to track the return path of the limb during the shot. It would be an interesting exercise.
This is much easier to do with a computer model however. ;)
Alan
Alan
Tuomo:
--- Quote from: avcase on April 01, 2019, 06:48:16 pm ---For maximum efficiency, the ideal situation is where all parts of the bow return along the same path as when drawn. When a bow shoots a very heavy arrow, this is approximately what is happening and efficiency is relatively high. If the design can maintain this for very light arrows without additional waves of limb distortion or vibration, then the light arrow efficiency will also be very high.
--- End quote ---
Solution: Rigid limbs. As Steve has said - minimize bending portion of the limb. Just like Turkish flight bows...
Badger:
I made what I called a hinge bow several years ago with very extreme recurves and reflex, something like 12". The bow was about 4" wide in the bending area which I think was no more than about 8" long up close to the handle. It broke down quickly because of set and hysterisis but in the initial shots it was the fastest bow I had ever seen bar none with a 10 grain per pound arrow. I think it was like 212 fps on the first shot. And dropped with every shot until it stabilized after about a dozen shots. Once it stabilized it had no real performance left but it did confirm what is possible if the right materials were used. Short working areas solve a multitude of design problems with bows. The stored energy was over 125% of peak draw force.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version