Recent Posts

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11
Bows / Re: Snake bow
« Last post by M2A on Today at 02:11:04 am »
Interesting idea thinning the outside of those turns. Makes sense.  I’ll have to keep that in mind when I take on some of the snakey staves I have collected. Sharp looking bow!
Mike
12
Bows / Re: Osage Selfbow
« Last post by M2A on Today at 01:54:12 am »
Congrats! You been putting out some real nice work. Enjoy seeing your work. Best wishes on a speedy recovery.
Mike
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Primitive Skills / Re: A simple leather project
« Last post by Pat B on Today at 12:43:27 am »
Nice work, Brian. Form and function.  8) :OK
14
Bows / Re: Black locusts bow
« Last post by Selfbowman on December 10, 2025, 07:52:43 pm »
Day five 32.1 will check it for three more days to see if it changes.
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Primitive Skills / Re: A simple leather project
« Last post by Pappy on December 10, 2025, 07:23:17 pm »
Nice BJ , looks like you are pretty good with leather to me. Pappy
16
Bows / Re: The best shape for a reflexed bow?
« Last post by Badger on December 10, 2025, 07:14:54 pm »
   Are you saying shorter bows store more energy?  I believe this to be false I have never seen anything to support this.

Shorter bows automatically store more energy - this we know - and also that reflex is another key factor. Now we have same length and same reflex. So the small differences we see come from the sideprofile (and tiller)

 I would agree that short bows tend to be more efficient. Many here will agree that right about 67" is an optimum length. .
17
Bows / Re: The best shape for a reflexed bow?
« Last post by sleek on December 10, 2025, 06:16:26 pm »
Quote from: simk on December 10, 2025, 05:33:45 pm
yes, Tuomo, I had around 50 or so different bows from different bowmakers on the shooting machine....maybe post that in a seperate thread, its sure interesting.

How do you optimize the front profile
The longbow is self stabilizing when strung - you can make it as narrow as you like without getting into stability issiues. A recurve needs a certain width at its base. At the same spot the longbow can be made much narrower resulting in a different top profile and mass difference. Your experiment does not take in acount relevant specific characeristics of the design. Namely the lighter limbs of a longbow, and the extra mass of recurves. If we compare the experiment with reality we also must say, that you put recurves mainly on shorter bows - 68" is a bit long to make a recurve.

But this is all about fps. If we only talk about stored energy and sideprofile and leave the fps aside, this a very good experiment.

Shorter bows automatically store more energy - this we know - and also that reflex is another key factor. Now we have same length and same reflex. So the small differences we see come from the sideprofile (and tiller).

Maybe Tuomo could upload the force-draw-curves? Visualizing the stored energy? Maybe we see a nice hump in the curve of the d/r?

And Tuomo: Do these bows all have same length of string? Any Differences?

Gettin' curious again  ;D

Do you still have the shooting machine set up? Im very interested in your experiments, please do post it, here or on another thread.
18
Bows / Re: The best shape for a reflexed bow?
« Last post by simk on December 10, 2025, 05:33:45 pm »
yes, Tuomo, I had around 50 or so different bows from different bowmakers on the shooting machine....maybe post that in a seperate thread, its sure interesting.

How do you optimize the front profile
The longbow is self stabilizing when strung - you can make it as narrow as you like without getting into stability issiues. A recurve needs a certain width at its base. At the same spot the longbow can be made much narrower resulting in a different top profile and mass difference. Your experiment does not take in acount relevant specific characeristics of the design. Namely the lighter limbs of a longbow, and the extra mass of recurves. If we compare the experiment with reality we also must say, that you put recurves mainly on shorter bows - 68" is a bit long to make a recurve.

But this is all about fps. If we only talk about stored energy and sideprofile and leave the fps aside, this a very good experiment.

Shorter bows automatically store more energy - this we know - and also that reflex is another key factor. Now we have same length and same reflex. So the small differences we see come from the sideprofile (and tiller).

Maybe Tuomo could upload the force-draw-curves? Visualizing the stored energy? Maybe we see a nice hump in the curve of the d/r?

And Tuomo: Do these bows all have same length of string? Any Differences?

Gettin' curious again  ;D

19
Bows / Re: Snake bow
« Last post by bjrogg on December 10, 2025, 05:00:39 pm »
Gotta agree with Badger.

Looking good Arvin

Bjrogg
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Bows / Re: The best shape for a reflexed bow?
« Last post by Tuomo on December 10, 2025, 04:05:13 pm »
Nice idea, Willie, and definitely worth trying. But I see many problems as well. How can I be sure that strain distribution is the main feature of an exceptional bow? Why not mass or curvature distribution, or the side profile combined with some other parameter?

I don’t have an exceptional bow—just some good ones. Their common features are that they have minimal set and they are deflex-reflexed. Set is a material-related parameter, and when making wooden bows, minimizing set is only possible when strain is distributed as evenly as possible. I’m going to make some bamboo-horn bows in the near future, so with horn the set parameter is almost eliminated. Simk has made a lot of very fast horn-belly bows and has taken very good and reliable measurements of their performance (see Traditionell Bogenschiessen 117), so there is potential. But again, this is how we implement theory in a real-life bow.

So, I’m going to make deflex-reflex (or even deflex-reflex-recurve) bows with evenly distributed strain and test them. A long to-do list…
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