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31
Bows / Re: The best shape for a reflexed bow?
« Last post by Tuomo on December 10, 2025, 12:06:09 pm »
Simk: How do you optimize the front profile, and especially the tapers? The front profile is more of a practical problem, because in the model you can make it as narrow as you want, but in real life stability becomes a real concern. That’s the main reason I wanted to use the same front profile for every bow model.
As for the taper rate, I optimized it with strain distribution in mind. What would be a better approach? The 0.008 taper I used seemed to work well for every model.

Ryan: Yes, energy storage is mainly determined by the unbraced profile. That’s exactly what I wanted to examine, and of course the results of that difference also. All the “bows” had the same net reflex, yet they still behaved very differently.
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Bows / Re: The best shape for a reflexed bow?
« Last post by RyanY on December 10, 2025, 11:35:01 am »
If we isolate the variables and assume that these bows are all evenly strained and 100% efficient then wouldn’t the difference come down to energy storage alone? I’m not sure what would make the difference just based on the unbraced profile. It’s hard to separate the real world effects that were used to making assumptions about such as strain, limb mass, hysteresis, limb vibration, etc.
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Bows / Re: The best shape for a reflexed bow?
« Last post by bjrogg on December 10, 2025, 11:34:10 am »
Very intresting Tuomo.

I think I shoot that bow Bob showed and it was a very nice shooting bow.

What would work best scaled down to a 24” draw.

I would be interested in the best performing length and reflex shape for a 24” @ 50 lb natural material Selfbow.

I’ve only done one deflex handle with static recurves . It was more draw length than I could comfortably draw at 28” .

Would the static tips in my bow add to much mass ?

It’s kinda hard to wrap my head around all the mechanics of a bow. Something so simple. Yet so complex.

Thanks for sharing

Bjrogg
I’d like to know the best front profile for it too.
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Announcements / Re: Coming back !!!
« Last post by Pappy on December 10, 2025, 09:13:13 am »
Glad to see ya back.
 Pappy
35
Bows / Re: The best shape for a reflexed bow?
« Last post by simk on December 10, 2025, 08:03:44 am »
Thanks Tuomo!
I'd say the results are intersting to get a general idea about these designs. The setback handle being worst and the d/r best will will most likely match with reality.
However: Having the front profiles and tapers not optimized will distort the outcome relevant. Especially having the same front profiles on all bows neglects specific advantages/disadvantages of these designs. The recurves need a lot more mass on the outers to stabilize than a self-stabilizing longbow. In my experience the theoretical advantages of recurves and other complex designs over longbows mostly get consumed with the additional mass required. Therefore I would cast into doubt  the "placements" 3-5 and also I think the gap between 1 and 6 is not that big.
 
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Announcements / Special deal for December BOM entrants
« Last post by sleek on December 10, 2025, 03:21:19 am »
If you enter a qualifying bow into the December BOM your name will also be entered into the end of year giveaway. I really hope to see a huge BOM turnout this month!
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Bows / Re: The best shape for a reflexed bow?
« Last post by willie on December 10, 2025, 02:58:05 am »
I also like the curvature graph—you can see exactly where the bow is actually bending.

Yes quite helpful with reflex/deflex and other profiles that are hard to judge when looking at the bow on a tiller tree.
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Bows / Re: The best shape for a reflexed bow?
« Last post by Tuomo on December 10, 2025, 02:29:11 am »
Here are the results I got from VirtualBow. Remember, no set, idealized situation, although 5 % damping in the model, 10 gn/lbs arrow, every reflexed bow’s tips are 100 mm (4") behind the belly side of the grip (thus about 70 mm from the back).

The deflex–reflex design performs well, while a handle-reflex design does not. The reason model 4 performed poorly is that the recurves didn’t open fully even at full draw; the string was still almost in contact with the base of the recurves.

Willie: Yes, in VirtualBow the ability to visualize the stress curve is a great feature. I also like the curvature graph—you can see exactly where the bow is actually bending.
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Bows / Re: Snake bow
« Last post by bentstick54 on December 10, 2025, 01:21:02 am »
Beautiful looking bow. Great job on it Arvin. Looks like a December bow of the month to me.
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Shooting and Hunting / Re: First deer with my Osage bow
« Last post by Pappy on December 09, 2025, 11:43:54 pm »
Nice buck, congrats. Pappy
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