Primitive Archer

I can't claim to have done all the work that Badger has (I don't know if anyone can), but his claim that set is exceedingly damaging to performance does seem to make sense to me. That implies avoiding set is more important than extracting the last 1% out of the wood.

Based on all the modelling I have done, a wide pyramid profile bow that uses levers at the tips will offer the best performance from the wood along with being the most forgiving in terms of extra weight not hurting performance as much as other designs. It strains all the wood equally, keeps the moving mass as low as possible and if you overbuild it by a few % the extra mass is mostly near the grip and doesn't hurt performance as much. Reflex may be worthwhile, because it increases early draw weight and that is good for performance as well, but you would need to look at the differences between reflexing the whole limb versus recurved tips.


Mark

I am working at a hotel these days. It's a great gig - easy work and I enjoy helping guests with their questions about where to go and what to do in the Black Hills.

Last week I finally got the phone call at the hotel I had been waiting for!!! This woman from a large city back east was inquiring about hotel rates and so on for next summer. I was happily giving her the answers she needed when she paused the conversation and said she had an important question for me. She asked in a very serious voice: "Is your hotel haunted?" I replied in an equally serious tone, "No. Our hotel is not haunted." Poor woman, I could feel her deflating on the other end of the line. Then I told her, "Ma'am, I have been in Keystone since 1883 and in all that time I have never EVER seen a ghost here." The silence on the line was deafening as I imagined her doing the mental mathematics. And then the line erupted in laughter. When her hysterical cackling died down she told me to book the dates, haunted or not, she wanted to stay here so she could meet me.

When I turned around, there was the general manager standing behind me with a grin on her face. "You know you are fired for that, right?" she said. "Yeah, I figgered." I responded. But then I do something every week to get told I am being fired. I love my boss, she's a one-of-a-kind real deal. If she tells me to go fight a bear I'll rip off my shirt, rub down with honey, and get to fighting the bear. Because I know she'd be right there beside me in the fight and fighting to win.

Sinew backed Scotch Broom can bend a verrry long way http://www.primitivearcher.com/smf/index.php/topic,32850.msg434816.html#msg434816

I ran my formula with the numbers you gave me and the dimensions are exactly what they need to be for the poundage.

I have opinions on the profile of a bow, but being uncertain of their accuracy, ill only say what I firmly believe to be true. The more you stress the inner limb, the more torque you get, the more you bend the outer limb, the more horsepower you get. The limbs profile AND length needs to be built according to those goals. Longer gives more torque shorter more hp. Which, is a large reason my shirt bows have a hard time keeping up with Arvins long bows in shooting broadhead, but also why his long bows struggle against my short in flight.

I agree about an agressive side profile stressing the limbs more, especially recurves that are getting the tips out ahead of the handle.

From playing with Virtualbow with various reflex and  deflex arrangements,  I am seeing more energy being stored in the inner halfs of the limbs and not as much as I had previously thought being added by bending the outers more.  That said I have just been playing with 62" bows and havent really spent a lot of time with longers designs - yet.

below are two graphs available in virtualbow that show the amount of curvature in the limb:
the first at brace and the second at full draw.  you can move the slider and watch the curvature change as you "draw" the bow.
Looking at the stress graphs sort of tells you the same thing,   Maybe the dedicated curvature graphs with its exaggerated scale helps some visualize better.  I can see the usefullness for someone who mainly builds glass laminates and tillers by tapering lams before glueup and doesnt often do a lot of sanding and trying to change the bend by eye after the fact
Using the shape view to see the changes in curvature after making a tweak to your model is not that easy, (for me anyways), especially if there is a lot of reflex or deflex



 

I always butcher my own meat, and I kind of enjoy it too.  Mostly I enjoy seeing a freezer full of meat and thinking, "Wow, I did that!"  It's a satisfying feeling of accomplishment.