boo backed ipe warbow dimensions?

[P.W. Smith]

does anyone have a good design/dimensions for a 90-100 lbs at 30 inch draw bamboo backed ipe warbow?
thanks,
Derek

[duffontap]

Hopefully Mark and Steve will chime in but if it were me I would go for about 1 1/4" wide at the handle, 1/2" at the tips (you could go 3/8" if you are confident in your abilities).  Length should be less than a Yew bow--Ipe and bamboo could easily handle 70" or less nock to nock.  As you start moving away from Yew-type dimensions you will lose authenticity but it will suit Ipe better. 

          J. D. Duff

[markinengland]

Not much to add to what JD said. My advice would be to shape and pre-tiller the belly stave before glueing on the backing, and preshape the backing as much as possible before glueing it on. Done this way the bow will almost make itself as little wood will need to come off.
Go carefull with reflex as once again a little goes a long way.
Go very carefull on initial layout. Run a fishing line (or single strand of dacron) between two weights along the stave, supported at each end with chopsticks or something to get a true straight line down the Ipe. As the bow will be so skinny getting that straight centre line is very important. Taping some masking tape to the Ipe makes marking with a pen easier. Getting good even tapers to the lines you have drawn will again be important. A small deviation in width or depth taper makes a big difference with such a dense and strong wood.
Mark in England

[stevesjem]

Hi there,
personally i make the stave up prior to shaping, however i do not use bamboo, but hickory, i make my stave 1 3/8" x 1 1/4" and along the back i keep it parralel for 16" either side of centre and then taper to 1/2" at the tips, on the belly i keep the handle area 1" above centre on the top limb and 3" below centre on the bottom limb and then taper to 1/2" at the tips, and i make the total length 78-80", this way i get a good performance bow without the worry of it going bang, i also find it gives me a larger bow dimensionall and as such it feels better in the hand when no hand grip is used, i also use a core wood of satin wood which is not tapered, this is just to reduce the overall physical weight. here is a picture of one i made recently. 120lb@32"
Hope this is helpfull.

Steve

[P.W. Smith]

okay guys...thanks so much for your help! I'm going to try to get to work on one and will hopefully post pics of it when I'm done
thanks again,
Derek

[markinengland]

Derek,
I was thinking about your post today. If any mild relfex is to be glued in I would advise an inch and an eighth rather than an inch and a quarter. That should be plenty for 90lbs, just take care to avoid hinges toward the tips area where width and depth tapers converge.
Mark

[P.W. Smith]

I was thinking of just a straight stave boo backed ipe with no reflex glued in...for me its much easier to tiller without reflex than with it. anyway, I finally got the ipe board cut out and have three bow blanks from it...I also am prepping some thick, strong-and yet unidentified pieces of boo that I picked up at a gardening store...does anyone have a good method for tillering these bows (short boo backed ipe style)

[Rich Saffold]

I'd want my final dimensions for the bow you describe to be 72-73" 1 1/8th" max 1" for the heavier ipe. Bamboo 1/8th-3/16th's thick, and I would glue it up with an inch of reflex. I know straight is "easier" but the bow limbs get a little more zip for their mass, and a little reflex isn't much over the length of that bow and not that hard to tiller. If you are comfortable drawing 90# bows than these bows really aren't that hard to floor tiller past stringing height. I just lay a little weight into the grip and focus on what I am seeing.

Get a bunch of good scrapers too..

Rich

[Badger]

       I would go along with Rich and JD on that.  While back I made one 110# at 28 that was 1 1/8 wide and 73' long. I wanted to see how far it would pull before it failed and I got it out to 34" and lifted a few splinters on my boo. Strong stuff. Steve