Working on a giant bow to beat Allen Case!

[Hawkdancer]

You will need a small tree for the arrow, and really big feathers for the fletching!  And a large crew to operate the drawing mechanism.  I'd like to see that work - from a ways off!  Ol' daVinci had some good ideas, a lot of them worked!  I sometimes wonder if he had alien influence, or some funny smoking stuff, or both!
Hawkdancer

[sleek]

Make a take down Steve! Use white oak, the shipyards use stave quality wood, to steam bend ribs and planks. What you need is out there. Call a few up, im certain they can offer help on sourcing it for you.

Gannon and Benjamin come to mind. A well known outfit up in Massachusetts.

[willie]

daVinci had some good ideas, a lot of them worked!  I sometimes wonder if he had alien influence, or some funny smoking stuff, or both!

Steve, your teasing us. We are having to guess too much. Is there a trip to burning man in your future?

2 feet wide and 32 feet long

a giant doug fir stave

I am open to a stack leaf design if I can get it to work right.

like a car leaf spring? some side by side stacking wold allow you get away from the 2 foot wide requirement

[Selfbowman]

I think it would need to be wider than 2'  for a 80' length. Not enough back for 24' draw. Arvin

[Badger]

 Arvin, building on a 12X scale. wider would be better but even getting a 2 ft piece is kind of tough.

[Selfbowman]

Yes I understand Steve about the availability. I have so many questions about this project. Seams very interesting though. I will be watching for sure! Arvin

[leonwood]

Oh this wil be fun to watch! Remember the other Davinci show you did, saw that way before I ever touched a bow and realized years later it was you when I saw the show again

[Bob Barnes]

if you made laminated limbs out of sheets of plywood it could easily be 48" wide...   

[Badger]

    I was trying to build each limb self bow but I may have to go laminated.

[avcase]

Do you plan to simply scale up an 80” bow made from the same material in order to get the dimensions?  I wonder how well this would scale?  For various reasons, the bending strength properties of large samples are not as good as small clear test samples, so you will probably have to go much more conservative.

Alan

[Badger]

   I was intuitively thinking the same thing Allen, theoretically the surface of the wood can't be under any more strain than a small bow but it seems there would have to be some extra strain from something so large I am not accounting for. I actually want to establish the feasibility of the project before I go to far. Working with a large piece of lumber would really simplify it but I am having my doubts as to whether or not they could handle sufficient strain.

[willie]

Sadly, the old growth trees that would yield some 30' limbs are getting scarce. I wonder just how much one would have to scale back their expectations for the strength of materiel with a lot of well done lamination?

it seems there would have to be some extra strain from something so large I am not accounting for.

I think the limb strains will scale with a static analysis, although the dynamics of the tip return speed might be something to look into.

[sleek]

I wonder if limbs will sag under their own weight?

[Badger]

  Sleek, depending on the wood the limbs will weigh somewhere between 1,000 and 2,000#, I don't believe they will sag, hopefully not anyway.

  Willie, just from some small tests I have played with it doesn't seem like it is going to scale up very well. The 20 footer should tell me a lot.

[Badger]

  Sleek, depending on the wood the limbs will weigh somewhere between 1,000 and 2,000#, I don't believe they will sag, hopefully not anyway.

  Willie, just from some small tests I have played with it doesn't seem like it is going to scale up very well. The 20 footer should tell me a lot.

  The testing will be based on a percentage of stored energy rather than peek draw force. Example. a 66" stores roughly 50# energy and we shoot an arrow that is about 1/1000  of 50#. So arrow weight of 1/1000 of stored energy is what the testing will be using.