(Yeller Wood) Osage Design Question

[gmc]

Hey Guys.

I just roughed out my first attempt building a bow out of Osage. I really want to get pretty close on the thickness so I'm not killing the bow on the tiller tree. Based on a 64'' bow, 1 3/8 wide fade, stiff handle, straight taper to 3/8 using 1.5 long fade with 4'' handle with flipped tips, where would be a good place to start with thickness at the fades? I know that floor tiller is a great place to start but I always over shoot seems like and not having any experience with Osage thought I'd better ask. I'm hoping for 55 lb. bow when its all said and done. Just get me close.

Any help would be most appreciated. 

Greg

[artcher1]

With that semi-pryamid design you're going to need at least an 1/8" belly taper ( 1/8" overall to tips/ 1/16" to mid-limb). Depending on the amount of reflex that belly taper could be less though. And of course the Osage's density will make a difference in finished dimensions too.   But with what you described I would start 5/8" thickness right outside the fades to 9/16" mid-limb and carry that 9/16" thickness clear to the tips. Just cut outside your lines to give yourself a little leaway during rough-out. Those are the dimensions I use for a slightly radius belly. For a more rounded belly just allow a little more thickness. Hope that helped.   ART

[gmc]

Thanks Art, that did help. I will be cutting close looks like because I'm at 9/16 right now but just a little wider than 1 3/8 at the fades. Guess I may have gone to far but I've been over shooting on the last couple and causing a lot of extra work to get down to my target draw-weight. I hope the wood has a high density....sounds like I'm gonna need it. Btw, the stave does have a couple inches of reflex, that may help as well. Thanks again for your input.

If I can control my tapper thickness close enough and not goof up too much on the tiller tree, I may just pull this off.

Greg

[Alpinbogen]

Bear in mind that (among many things) the final thickness will depend largely on whether your belly is flat or radiused.  My own radius bellied osage bows are around 7/8" thick right at the end of the fade/limb flare, and about 3/4" thick an inch beyond that.  Mid-limbs are about 9/16" thick and tips about 7/16" thick.  Though I seldom build flat bellied bows, the thicknesses are much less, particulary from fade to mid-limb.

[artcher1]

I like to start my belly taper and inch or so past the side/handle taper like what Alpinbogen described also. Yeah, that 9/16" is going to mighty close I expect. Let us know how things work out. What's your draw length? ART

[gmc]

Thanks Alpinbogen. I will take that into consideration as well.

Art:
My draw length is about 28''. I have been using some pretty high density Hickory that would give me about 65lbs. with those same dimensions at 1.75 width, so with the extra density on the Osage I thought it would be ok. I was shooting for an 1.5 width on this one but got a little rasp happy shaping things up today. It will be whatever it is, this is my first with Osage so we'll learn all we can and apply that to the next one. You bet, I will post my results if there is one. I need to taper the belly and torture it on the tiller tree, first. I flipped the tips up a little more than I should have probally but we'll see. A lot of first time doing things on this one.

Thanks, again.
Greg

[sulphur]

don't get to caught up in numbers.  osage can be very touchy sometimes.  However i think archer is right, start somewhere in the 9/16 range.  i would suggest a uniform limb thickness and then start working the mid to outer limbs down slowly (since this is your first) and check tiller often.  your dimensions are more than adequate for what you want.  good luck, don't forget the pics!!

[PeteC]

If your going with a straight taper with a flat belly,start with 1/2" thick limbs from fade to tip.This is where I start ,without,as you say,"workin' it to death on the tree". God Bless

[Pappy]

I usuall start at about 5/8 and don't worry about the limb tapper.I let the tiller determan that.
It's wood and usually not uniform in density through its length. For that length bow and with
it will probably wind up about 3/8 anyway. It may wear on the wood a little but I like to start plenty heavy when floor tillering and get it on the board as soon as possible so I can solve any problems
the stave may have. Before I get close to weight. 
   Pappy

[gmc]

Thanks Sulphur/ PeteC.

Sulphur:
Just looking for a baseline to start. I don't worry so much after the first one.

PeteC:
That is pretty much what I had figured to start with. One my last bow I left way too much work on the tiller tree.

I will take some pictures along (I always do) and will post the results, if there is one.

Thanks again for the help, guys.

Greg

[gmc]

Pappy:
I agree with your process, that what's I normally do. But being a bit more "growth ring" aware on this one, even on the belly, I'm more worried more about coming in under weight on this one by removing too much wood to start with, but with the higher density wood I don't want to over shoot either. Your upfront layout means a lot with how a bow turns out. I have found the more time spent upfront and less work on the tree yields a better result in the end. If that makes any sense....

This piece of Osage had really thick rings (1/4 inch) deep into the stave but about 1/8 inch closer to the top. I will be glad to get through the first one here, then I can not worry so much. 

Thanks Pappy.