The best shape for a reflexed bow?

[simk]

Ok, ok, for the scienece we measure 

Are the pictures from bows 1, 4 and 6 Tuomo? If so:

Bow 1 angle 52.1 degrees - stored energy 101.3%
Bow 4 angle 53.9 degrees - stored energy 107.5%
Bow 6 angle, 49,9 degrees - stored energy 118%

with bow no 4 I'm not sure weather I measured correctly. Maybe measure from the very tip, and  not the place where the string touches?
do you have the fd pic for the other bows too?

[Tuomo]

Interesting analysis for string angle! Let's see what you can get from these. By the way, what is the program you use?

[willie]

Isn't it the shallow angle at brace that gives the high early draw weight and increases stored energy?
whereas  excessive angle at full draw leads to stacking or an increase in apparent draw force but  not stored energy?

[simk]

Good point willie. when the string touches the bow gets shorter virtually? complicated things. but something happening for sure, you can see that on the chart too. we here check only the angle at fd.
Tuomo, its autodesk fusion - pretty cool software for 3d design. they even had a FEA analysis addon, not for free version tough...

[willie]

complicated things. but something happening for sure, you can see that on the chart too.

a compressive force acting linear on the limb in addition to the compression due to bending?
maybe why such designs are more prone to compression failures?

[Badger]

    I misspoke earlier. It is the Gary Davis form that I adapted as my regular.

[Bob Barnes]

    I misspoke earlier. It is the Gary Davis form that I adapted as my regular.

I copied Gary's for at MoJam many years ago and it's the only reflex for I have ever used.  My D/R form is an adjustable model that I also copied from a MoJam form that was made by Patrick Bumgardner.

[sleek]

Patrick has made probably the most powerful bow for its draw weight ive ever seen. He isnt on here much anymore, but his handle is Lebhuntfish.

[Bob Barnes]

Patrick has made probably the most powerful bow for its draw weight ive ever seen. He isnt on here much anymore, but his handle is Lebhuntfish.

It was built using this (his original) form.

[Tuomo]

Isn't it the shallow angle at brace that gives the high early draw weight and increases stored energy?
whereas  excessive angle at full draw leads to stacking or an increase in apparent draw force but  not stored energy?

Yes, just like that! If you play with VirtualBow, you will find that the more string contact there is (especially with deflex–reflex designs), the more energy is stored. However, this requires that the string contact opens; in other words, there must be no string contact at full draw. See Model 4 with 90-degree recurves: because it does not open even at full draw, it is not a good design.

However, measuring the string angle at full draw is not very practical. As Simk said earlier, “It’s enough if we understand the concept and know the general guidelines to keep the angle low.” With the VirtualBow program, it is quite convenient to model different kinds of bows and gain a better understanding of bow behavior.