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Shooting and Hunting / Re: First deer with my Osage bow
« Last post by Piddler on Today at 08:39:42 pm »
Congratulations on a nice buck.
Piddler
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Shooting and Hunting / Re: Another good day
« Last post by osage outlaw on Today at 06:53:03 pm »
You are knocking them down this year Pappy!   (SH) :-D
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Shooting and Hunting / Re: First deer with my Osage bow
« Last post by Pat B on Today at 06:09:38 pm »
Beautiful buck and nice shooting.  :OK
Welcome back.
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Bows / Re: Snake bow
« Last post by Selfbowman on Today at 05:57:54 pm »
35@24 one coat true oil . Couple more costs and off to my leather man for the handle rap.
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Shooting and Hunting / First deer with my Osage bow
« Last post by Woody roberts on Today at 05:01:11 pm »
Wow! I’m glad to see this forum up and running again. Got my first deer with my Osage bow this year. My old Sudbury still shoots good and has put a few on the ground but I thought I’d give the Osage a chance. 22 yds centered the heart. A little farther than I prefer but I take the shots they give me.
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Bows / Re: The best shape for a reflexed bow?
« Last post by willie on Today at 03:28:31 pm »
So more taper → more evenly distributed stresses and lighter limbs.......
I tried my D/R model using a 0.010 taper (more taper)......  the maximum strain values were higher.
With less taper (0.006).....the maximum strain values were slightly higher.
Was this with the same width width profile? A limb can be made stiffer, or for the sake of this discussion, less stressed, anywhere along the limb where the stresses are maxing out.
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In VirtualBow, I get maximum speed and minimum strain when stresses are distributed as evenly as possible (within reasonable limits, of course).
In real life, we cannot “see” strain values, so it’s difficult to tiller perfectly, but we can learn a lot by using programs like VirtualBow.

visualing the stress curve with the program, is to me, its strongest feature.

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The question is that how do you optimize the tiller? What is the parameter which is altered? More bending towards the tips, or handle? Something else?

In theory (and in generally accepted widsom), bend towards the handle does the most for energy storage. So for me,  it becomes where a designer would seek to place the highest stress on the curve, but also keep it as level as possible without the stress curve peaking too much, finally deciding where along the limb length to have the stress curve begin its downward slope towards the tip where stress and bend is zero.

Looking foreward to your presentation!

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Bows / Re: The best shape for a reflexed bow?
« Last post by Badger on Today at 02:21:09 pm »
    I agree with you Bob on the Mark St Louis design. They are the fastest I have tested. They take a bit of skill and patience to pull off. To generalize a little bit I think it is safe to say that a simple composite bow ( wood or bamboo backed) will usually shoot about 10 Fps faster than a self-bow. So if we just talk self bows, I think it is safe to say that a straight pyramid self bow that is well designed with good wood and tillering will usually shoot between 168 fps to about 172 fps. If you go to an r/d design with 1 1/2" reflex, you are usually looking at 172 to about 176 fps. Recurves with about 2" behind the back usually about 175 to 182. There are a lot of exceptions.

  My personal favorite is the R/d design and I am happy with anything over 172 for a self-bow.  The difference is relatively small between the bows. For flight shooting the most important thing is getting the arrow out of the bow cleanly; that's why simple designs usually do well. You can lose a lot of speed in the first 10 ft of arrow flight if the arrow comes out sideways before it straightens out.

   There has always been the catch-22 when it comes to energy storage VS efficiency. When you talk about efficiency, you are examining where your losses are. The two biggest and most controllable sources of loss are vibration and hysteresis caused by the set. The vibration can be reduced significantly by reducing the amount of working  limb. This can also aggravate the set issue. The best way to mitigate that is to have the middle and inner limb do all the work and keep it wide. Extreme designs will usually shoot very fast for a few shots but quickly break down to mediocre performance if not designed properly. Wood has its limitations and a man has got to know his limitations.
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Bows / Re: The best shape for a reflexed bow?
« Last post by Bob Barnes on Today at 02:18:43 pm »
Bob, I dont think all the theories helped me a lot with my bowmaking. My most important lesson was: Make your bow look pleasant to the eye. a good looking bow usually is a good shooter.

For a wood only bow I'm very close with Arvins Design. I personally make them a little narrower and less pyramid but also put that slight reflex towards the outers. Those shoot very comfortable and plenty fast - I like others too, but I think this is my fav design for wood.

simk, I absolutely agree.  I forgot to mention your full draw photo posted earlier.  The bow just looks too good not to be a great shooting bow.   :OK
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Bows / Re: The best shape for a reflexed bow?
« Last post by simk on Today at 02:15:13 pm »
Bob, I dont think all the theories helped me a lot with my bowmaking. My most important lesson was: Make your bow look pleasant to the eye. a good looking bow usually is a good shooter.

For a wood only bow I'm very close with Arvins Design. I personally make them a little narrower and less pyramid but also put that slight reflex towards the outers. Those shoot very comfortable and plenty fast - I like others too, but I think this is my fav design for wood.
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Bows / Re: The best shape for a reflexed bow?
« Last post by Bob Barnes on Today at 11:25:42 am »
This has been a very educational thread.  Thank you.  It seems like there's going to be even more information added before it is complete.  I'm not an engineer that understands all of these science/physics concepts, but I have made, owned, and shot a lot of bows and base my opinions on that.  The fastest selfbow I ever owned/shot was made by Marc St. Louis.  It was highly reflexed and also had static recurve tips.  The bow shot a 10gpp arrow 199 fps.  It has always been a quest for the best all-around combination of speed and shooting characteristics.  Most of the speed bows didn't shoot my hunting weight arrows well or were not pleasant to shoot many arrows from a day.  When I settled on the DR design it was just because it shot as fast as nearly all of them, plus it was very pleasant to shoot.  I also agree that the design benefits from having the tapers correct.  There is a fence 200 yards from my shop door, and it serves as a testing site when a bow is being made.  It seems like the best ones will always send a 10gpp arrow over that fence...which is OK because it's my hay field on the other side of the fence.  :)  Thank you for the sharing of so much knowledge.   :OK
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