Author Topic: Flatbow design and length  (Read 345 times)

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Offline PatrickH

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Flatbow design and length
« on: May 23, 2020, 06:41:06 pm »
So, I have been shooting a redoak ALB I made that is quite long (74in ntn) that pulls about #45@30in. I am just beginning tillering a new 64in Elm flatbow. If my bow design knowledge is right (correct me if I am wrong please) a shorter bow will have lower energy storage than a longer bow with similar design? Is there any kind of rule of thumb that would tell me how much heavier of draw weight I would need to get roughly the same arrow speed from a shorter bow? would a 5 or 10 lbs increase in draw make up for the loss of string angle caused by the 10" shorter limbs? I might be over thinking things. I just wanted to make a shorter bow that is easier to carry through the brush but would still have roughly the same (or better) arrow speed. If it matters this is a elm flatbow, that will bend slightly in the narrow handle when I am done and I am aiming for about #55lbs@29in. Thanks in advance for the help.
Muskegon Mi.

Offline Ryan Yoon (ryoon4690)

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Re: Flatbow design and length
« Reply #1 on: May 23, 2020, 09:13:30 pm »
64 is plenty long for a fast shooting bow. If built well you likely wont notice any difference in the hand. If both bows are well made the difference is likely only a couple fps. Shoot whatever draw weight is comfortable. Id be more worried about a 30 draw out of a 64 bow. Unless designed for that long draw length, itll stack in the last few inches of draw.

Offline PatrickH

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Re: Flatbow design and length
« Reply #2 on: May 24, 2020, 08:25:24 am »
Okay thank you Ryan, I was thinking of making it bend in the handle slightly (i think that helps with stack right?) and have a 29" draw. I guess I will just get the tillering farther along and measure the f/d curve at like 26in fully braced and see what its doing before I finish the tiller. Thank you for the help.
Muskegon Mi.

Offline Ryan Yoon (ryoon4690)

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Re: Flatbow design and length
« Reply #3 on: May 24, 2020, 08:57:28 am »
If it bends through the handle it should be fine in terms of stacking unless the tiller is quite elliptical.

Offline bradsmith2010

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Re: Flatbow design and length
« Reply #4 on: May 24, 2020, 09:29:17 am »
its possible 64 inch bow might shoot harder than the longer 74 inch bow,,
lots of variables,,
energy storge does not always translate into more speed
the longer bow has more mass,, that could make it slower,,a chrono would help
the well built and tillered 64 inch bend in handle should shoot as well or better than the longer bow,,
but with all the varialbe im just guessing,, if you told me what the longer bow is shooting fps with 10 grain arrow, I or we could make a pretty good guess,,if that is possible,,
a few fps either way is not gonna make a difference in taking game,, you can shoot a lighter arrow or fast flight and up the speed if that makes you feel better,,

Offline PatrickH

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Re: Flatbow design and length
« Reply #5 on: May 24, 2020, 04:21:50 pm »
Ok thanks guys! Its not quite at brace tiller yet, but when it is I will post it and get feedback, I appreciate the help.
Muskegon Mi.