Primitive Archer

The design I’ve been using for years is closest to the third design. The speeds are close to what I get most of the time. I have had upward to 186 ft per second. Not often though. Interesting topic thanks for sharing. Notice the farther the tips get in front of the back of the bow the more speed. That’s with the deflex in the handle to help the stress on the inner limb.

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.

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.

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.
 

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.