Author Topic: Input for a new flight bow  (Read 2356 times)

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Offline joachimM

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Input for a new flight bow
« on: January 26, 2023, 03:43:43 pm »
Hi Folks, I would like to reach the goal of shooting 300 m (some 330 yds) with a 50# bow, either a so-called primitive self bow, or a primitive composite. The best I've ever shot with a self bow is some 230 m (a plum recurve), with a primitive composite (backed with a layer of plant fiber) that was 265 m. both were with pretty light carbon target arrows (I've never really got the hang of making my own arrows, let alone flight arrows)
I'm clearly not pushing my designs far enough, so I 'd like your input. How skinny do you make your tips? What about the tips of recurves?
 
I have a quite some pretty decent staves and boards to my disposition: enough english yew for a dozen longbows, lots of black locust logs waiting to be cut or split, really nice elm staves and logs, a few plum staves good enough for longbows or recurves, a few maple boards, ...
 
So if you had your pick for a primitive flight bow design, what would it be, and why?


thanks for any input!
Joachim

Offline Badger

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Re: Input for a new flight bow
« Reply #1 on: January 26, 2023, 04:32:06 pm »
 The arrow is more important than the bow.

Offline joachimM

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Re: Input for a new flight bow
« Reply #2 on: January 26, 2023, 05:30:44 pm »
Ha, I'm sure you're right on that, but
1) that doesn't answer my question (what flight bow would you make with what I have at hand?)
2) I don't presume I have ever made a bow that was close to being good enough that arrow quality would come into the equation ...
3) the science and alchemy of flight arrows is beyond my reach, I fear. I've seen quite some discussions here on flight arrows and couldn't figure out what makes a good flight arrow, ultimately. So I'm left with the part I can control, and I'll try different types of arrows to go with the bow until there's a combo that sticks I guess

J

Offline Badger

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Re: Input for a new flight bow
« Reply #3 on: January 26, 2023, 09:30:15 pm »
Any slightly reflexed pyramid bow will reach the distance you are after, No bow will reach the distance you are after without an almost perfect arrow.

Offline Badger

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Re: Input for a new flight bow
« Reply #4 on: January 26, 2023, 10:50:34 pm »
       There are some design features you want to keep in mind. You will be shooting light arrows so efficiency will be your biggest challenge. Some of the biggest losses in efficiency come from hysteresis which is primarily caused by set, so a low set bow will trump most all design features. Another big loss of efficiency comes from vibration in the limbs, I think of it more as distortion than I do vibration. The limb tips can get ahead of the bow limbs and the arrow leaves the bow before all the energy has been taken out. There are a couple of ways to avoid this, light weight tips are important but also less working limb means less limb to distort. Generally speaking with some exceptions wood bows should not be designed as fiberglass bows. They will simply take too much set. Simple designs like a 62" pyramid bow reflexed about 2" with very light tips is a proven design.

Offline joachimM

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Re: Input for a new flight bow
« Reply #5 on: January 27, 2023, 09:25:36 am »
thanks a lot for the advice, it's much appreciated.
Am I right that I should try to make shorter draw bows, rather 24" than 28"? If so, is that to limit set, or because arrow flight is cleaner?

J

Offline Badger

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Re: Input for a new flight bow
« Reply #6 on: January 27, 2023, 01:45:45 pm »
Suppose you make a 25 1/2" draw from the back of your bow. You will use a 24" arrow. Measure the spine on your arrow at 22" centers using a 2# weight. You will be looking for about 1" deflection. The biggest mistake I always made was using arrows that were too stiff. I just learned this my last time out. Also use arrows between about 180 grains to about 210 grains or so.

Offline joachimM

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Re: Input for a new flight bow
« Reply #7 on: January 27, 2023, 01:54:41 pm »
Allright, thatís some great info. Thanks a lot! Iíll keep you posted on any progress (or failures).


Offline Chumash

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Re: Input for a new flight bow
« Reply #8 on: January 27, 2023, 02:17:42 pm »
Test these arrows with a tempered Mollegabet style bow out of elm. Length about 54" to 60 ". Length of the lever about 8" (very small, may be slightly bend forward (recurve)). Bending something like a  idea in the grip. Most bending in the wide part of the bow an no bending in the lever.