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11
Bows / Re: Black locusts bow
« Last post by Jim Davis on Today at 01:15:08 pm »
When I lived in Maine, BL was the best wood I could easily get.

My first use of it was from a small tree that only allowed a 1-1/2" wide stave. I made a pyramid design bow that was nearly perfect tiller at #35. It had about 3 inches of  reflex. I shot it a lot and it performed well. Then I discovered that the belly had a parade of frets from one tip to the other--the whole belly.

With nothing much to lose, I just kept on shooting it. Eventually, I over drew it and it broke.

For the next few years, I made all my bows with backs narrower than the belly. But my subsequent research found studies that indicated that wood only stretches about 1% before breaking. SO, narrowing the back does not make the tension wood stretch more to accommodate the compression of the belly.

We all know that if we bend any piece of wood far enough, it WILL break. The balance for bowyers is in making the limbs thin enough to not yield (take set) at the amount of bend (draw length) we want. At the right thickness for the bend, the weight will be determined by the limb width.

My best locust bows were pyramid design, a little under 1/2" thick, 2-1/2" wide at the fades, 68" NTN and about #40 at 28".
12
Arrows / Re: Chrono tests
« Last post by Robert Pougnier on Today at 12:29:26 pm »
Rock maple bow with 575gn arrow.

I unfortunately don't have, at the moment, any exact 10 gpp arrows for any of my bows.
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Arrows / Chrono tests
« Last post by Robert Pougnier on Today at 12:27:28 pm »
Put two different arrows through the chronograph today, with two different bows. Just out of curiosity and for education's sake.

one arrow is 575gn, the other 300gn.

One bow pulls 50#, the other pulls 43#. Both drawn to 28 inches.

Here are the results

50# pyramid reflex shot a 575gn arrow at 140fps. Chatgpt (i know lol) estimates for a 10gpp arrow this would be between 148-153 fps. Not bad.

With the same bow, the 300gn arrow was shot 158 fps. I can't promise my release is consistent, but I was trying for consistency in release and draw length.

Next set of photos is a 43# rock maple bow with reflexed tips. It shot the 575 gn arrow at 127 fps. Again chatgpt estimates about the same, 150fps with a 10 gpp arrow. Not bad either.
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Arrows / Stone point tests.
« Last post by Robert Pougnier on Today at 12:16:13 pm »
I made two sacrificial arrows with my least favorite points. This is my first time testing stone points.

They did great, with decent penetration until I backed up and shot high with both. They punched through the backdrop and hit 2" thick pine. You can guess what happened  (lol)
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Arrows / Whoops!
« Last post by Robert Pougnier on Today at 12:13:44 pm »
I was testing different types and batches of arrows today (more pics next topic) and this happened. I almost wished the nock wasn't wrapped so well so we could have seen how far the arrow split. I hit it with a sharpened duplex nail
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Bows / Re: Black locusts bow
« Last post by Pat B on Today at 12:01:46 pm »
I cut my bow building teeth on locust. I started buying locust fence posts for $5 each. Made lots of bows but they all fretted. My only success was with an Eastern Woodland style bendy handle bow I made for a bow trade.
 The locust that grows around on our property has something that causes the early growth rings to deteriorate and separate so all of the bows I tried with them have failed. I think there are a lot of variables when it comes to locust, at least around here.
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Bows / Re: Rule of thumb for stored energy
« Last post by Badger on Today at 11:11:55 am »

In my opinion, defining a draw-force factor would be the best approach for estimating stored energy for a specific bow. This factor can be determined by measuring the draw-force curve of real bows and/or by modeling it using a program such as VirtualBow.
[/quote]

   I agree with you 100%, the chart is not to be used by the bowmaker. That is just for the purpose of building a database that would help us establish the factors we need to use. The bow maker would simply take the draw weight and multiply it by his factor. He would know that is what he is looking for at 1/2 draw. Years ago I built what I called a super reflex with giant hooks and 12" backset. That used a factor of .6 X 50 = 30. So I would be looking for 30# at 1/2 draw. A typical r/d might use a factor of .52 for example. I think it would be a helpful barometer for those interested in such things.
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Bows / Re: Rule of thumb for stored energy
« Last post by Tuomo on Today at 08:58:06 am »
I think that estimating stored energy is quite straightforward. Take the maximum draw weight (DW) and the power stroke (PS), then use the formula 0.5 × DW × PS.

For example, consider a 50# @ 28" bow with a 6" brace height. This gives 50 lb draw weight and a 22" (1.83 ft) power stroke, so: 0.5 × 50 × 1.83 = 45.8 ft-lb.

For a straight bow, this is a good estimate because the draw-force curve is almost linear. For reflex and recurve bows, the stored energy can be multiplied by a factor of 1.05–1.25, depending on how much backset the bow has (more backset gives a higher factor). This factor arises from the draw-force curve being “fatter” for bows with greater backset. For a straight bow, the factor is 1.0, and for deflexed bows it can be under 1.0.

In my opinion, defining a draw-force factor would be the best approach for estimating stored energy for a specific bow. This factor can be determined by measuring the draw-force curve of real bows and/or by modeling it using a program such as VirtualBow.
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Primitive Skills / Re: Life is good
« Last post by Pappy on Today at 08:22:33 am »
Ya pretty busy weekend, Got the doe given to me skinned and boned out yesterday and Beau's buck draining so 2 left to process and package, freezer is filling up and that's a good thing. :) Yes Clint that things works like a champ, thanks for sending it to me, much appreciated and yes hope it works out you can make it back down, as you said been to long, I miss seeing you and all them yahoos that hang out in your camp.  ;) :) Now that Miss Joanie is on the road to recovery it's my turn, headed to doctor this morning to see about my shoulder, not any better so I feel sure I will be laid up for a while, guess I will get to see how all this stuff I do works with 1 arm, at least it's my left arm and I am right handed.  ;) :) :)
 Pappy
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Primitive Skills / Re: fur on tanning with egg?
« Last post by GlisGlis on Today at 05:27:55 am »
Here’s a video I did on tanning a fox hide. Same basic steps for most fur on pelts. Just add a thinning step for otter, beaver, and the shoulders and hips of raccoon. I use an angle grinder with sanding disk.

https://youtu.be/LvYBbcW7giQ?si=p_wFCtRELv6mbuNh


nice informative video there kyle. thankyou  :OK
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