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Main Boards => The Bowyer's Bench => Topic started by: razorsharptokill on September 09, 2009, 05:53:00 PM

Title: BBO formula?
Post by: razorsharptokill on September 09, 2009, 05:53:00 PM
I have some awesome Osage lams from  KennyM and the boo I have is now a little over an inch wide due to a slight oops with the table saw while flattening.

The boo is 69.5" long, the lams are .340 thick in the center. What do you guys think about a 66" longbow. Do you think it will be too weak?
Title: Re: BBO formula?
Post by: Okie 1 on September 10, 2009, 01:30:00 PM
Jim, are you talking about 1 lam with the boo. If so I'd say it'd be too light for hunting weight... Depends on what "too weak" means to you. My core wood for my BBO's start out at 5/8" thick x 1 1/2" wide. Hope that helps.
Title: Re: BBO formula?
Post by: razorsharptokill on September 10, 2009, 03:54:00 PM
I've got two lams, one taper and one parallel their combined thickness is .340 at the thickest point.
Title: Re: BBO formula?
Post by: Okie 1 on September 10, 2009, 04:22:00 PM
Maybe some one will jump in with a little more knowledge about lams but, .340 is about 11/32nds so I'd say you'd end up with a bow around 30lbs. Just my guess though.
Title: Re: BBO formula?
Post by: Dano on September 10, 2009, 06:10:00 PM
I think your right John, .340 might have been fine for a wider bow, but 1" is kinda narrow.
Title: Re: BBO formula?
Post by: No-sage on September 11, 2009, 09:10:00 AM
My best shooting BBO was 1" wide, 62" long, mid 50#.

I always start with a tapered slat that is 5/16" thick in the center, tapering to 3/8" at the tips.

I didn't make it that narrow on purpose, it came out that way because the glue lines were lousy at the edges and I had to narrow the bow to get rid of some gaps.

If you have bowmaking experience, you should be able to make a hunting weight bow from your wood, but it will have to be shorter than 66".

 (http://mysite.verizon.net/vzep2hbr/sitebuildercontent/sitebuilderpictures/sliverbboprofile.jpg)  


This is the widest point on the bow.


 (http://mysite.verizon.net/vzep2hbr/sitebuildercontent/sitebuilderpictures/sliverbbo2.jpg)

 (http://mysite.verizon.net/vzep2hbr/sitebuildercontent/sitebuilderpictures/sliverbbodrawn.jpg)
Title: Re: BBO formula?
Post by: Okie 1 on September 11, 2009, 10:41:00 AM
Quote
I always start with a tapered slat that is 5/16" thick in the center, tapering to 3/8" at the tips.
So your slat is thinner in the middle then the tips??
Title: Re: BBO formula?
Post by: Okie 1 on September 11, 2009, 10:43:00 AM
Nice bow by the way! What is your handle laced with?
Title: Re: BBO formula?
Post by: No-sage on September 11, 2009, 01:30:00 PM
OOOPS..... I'm wrong......  I start with 7/16" at the center.  You may not have enough wood there after all, unless you go real short.

John...   It's round leather lacing I found at the craft store.
Title: Re: BBO formula?
Post by: Tom Leemans on September 11, 2009, 03:21:00 PM
Make a lighter weight bow out of it for a kid or something, then "accumulate" some stuff for another bow.
Title: Re: BBO formula?
Post by: Okie 1 on September 11, 2009, 08:07:00 PM
No-sage, it looks like copper wire in the pic to me. Cool looking though.
Title: Re: BBO formula?
Post by: razorsharptokill on September 13, 2009, 10:19:00 PM
My boo is a little over an inch at center but not by much. I'll post some pics when I get it glued up.
Title: Re: BBO formula?
Post by: razorsharptokill on September 22, 2009, 10:38:00 PM
Well I went to my back up piece of boo. It is wider. The crown on these pieces required that they be some what narrow to get them flat. I got it glued up tonight. We'll just have to see how it turns out.
Title: Re: BBO formula?
Post by: razorsharptokill on September 23, 2009, 08:35:00 PM
Got it off the form. I left it 68" tip to tip. It floor tillers pretty easily. I'm thinking 40ish if I pike it to 64". Glue lines look great though.
Title: Re: BBO formula?
Post by: Dano on September 23, 2009, 09:52:00 PM
Sounds good Jim, can't wait to see the finished bow.
Title: Re: BBO formula?
Post by: razorsharptokill on September 23, 2009, 10:28:00 PM
I used smoothon and mostly spring clamps. The power lam is made of Kingwood that has a very purplish color to it. The handle will be two lams of that with Osage in between.

I could glue another parallel lam of osage to the belly to thicken the stack. Any thoughts on this?
Title: Re: BBO formula?
Post by: razorsharptokill on September 24, 2009, 06:34:00 PM
ttt
Title: Re: BBO formula?
Post by: tommy6 on September 25, 2009, 11:18:00 AM
You could do a few things to it depending on the shape. Any reflex to it?
You could add another parallel lam to it, around .04". The problem is that you will not be able to tiller it thru scraping the belly, it would have to be done by width taper. Another option would be to add a piece of boo to the belly thats been heat treated.
Of course the easiest thing to do would be to pike it till it reaches your desired weight.
Recurving the tips is also an option, but dont heat too high or you will delaminate it.
There is always an alternative option...
Title: Re: BBO formula?
Post by: Tom Leemans on September 25, 2009, 03:32:00 PM
Razor, I did that very thing to build up a bow with a thinner set of slats I had lying around. I used a full length lamination of walnut between the osage and the boo. It makes for lively limbs. That bow has held up very well. I shoot it the most, and it's my favorite hunting bow.
Title: Re: BBO formula?
Post by: razorsharptokill on September 25, 2009, 08:47:00 PM
The boo and osage lams are already glued up. There is minimal deflex and some reflex.

I have the 12" lams in the tips like the Dryad Hunter to keep the tips stiffer. They are between the osage lams. I have some elm also but it is a tapered.

What about boo on the belly?
Title: Re: BBO formula?
Post by: tommy6 on September 26, 2009, 08:46:00 PM
I dont think elm would stand the compression and would chrysal, happened to me i very similar bow. Boo makes a good belly, not an easy thing to tiller, would certainly take the compression. Hows the tiller now?
Title: Re: BBO formula?
Post by: razorsharptokill on September 28, 2009, 08:19:00 PM
Havent put it on the tree yet, just got the handle glued on tonight. I remeasured it at the center line and it is 1 1/4. Not sure how I got that measurement so wrong... I looked at the glue up and there is one spot just after where the fade will be that is about 1 1/8".  About 1/8" of the power lam is visible when viewed from the top.

I guess I'll have to trim that side of the handle a little to get rid of this problem then re-draw the angle from the fade to my outter mark on the tip for that side.
Title: Re: BBO formula?
Post by: razorsharptokill on September 29, 2009, 10:23:00 PM
Ok, got it strung tonight and have it drawing about 40 @ 24".  I cut the nocks in at 1.5" from the tips. Tip to tip it is 68" so  it's 65" NTN.

Got pics but battery is now dead. I'll post some pics tomorrow.

My glue lines turned out good with the smoothon. The Kingwood still has its purple tint and really looks good with the osage.
Title: Re: BBO formula?
Post by: razorsharptokill on September 30, 2009, 09:22:00 PM
Sorry for the links.

Here it is after cleaning up the glue lines.
http://images.yuku.com/image/pjpeg/0fa16a4b4aa3c4866a0b62d249957bc8f1c22835.JPG

Braced.
http://images.yuku.com/image/pjpeg/a8a1644c41a9c1816428435163f7a56eb86d1d5d.JPG

http://images.yuku.com/image/pjpeg/a2136362486542fbaca8ce77854b66145317f422.JPG

Riser side view.
http://images.yuku.com/image/pjpeg/f8716e4e4da3c78a6463641ce4140d5299ff9865.JPG

Riser center top view
http://images.yuku.com/image/pjpeg/f0a26b84364a3aa5c6988c6aa23d83b95dd955a6.JPG

profile after tillering to 40 @24".
http://images.yuku.com/image/pjpeg/9e626a34924cba3fc3082c60952b6b38605469d5.JPG

http://images.yuku.com/image/pjpeg/2ef269941b4daa6cc3b82b68377dd410b6c2322b.JPG
Title: Re: BBO formula?
Post by: Dano on September 30, 2009, 10:01:00 PM
Lookin good Jim, what draw weight are you striving for?
Title: Re: BBO formula?
Post by: razorsharptokill on October 01, 2009, 10:45:00 AM
I'd be happy with 45 on this one. I've got room to pike it an inch. What do you think about the outer 2/3's, too stiff?
Title: Re: BBO formula?
Post by: Dano on October 01, 2009, 11:06:00 AM
"What do you think about the outer 2/3's, too stiff?" Not too bad, kinda the nature of these bows.
Title: Re: BBO formula?
Post by: razorsharptokill on October 08, 2009, 09:43:00 PM
Now I can't post pics at all. My yuku account won't let me upload pics now. The Kingwood looks awesome with the osage I glued the tip overlays on tonight. They are Kingwood also.

The handle is shaped and feels very good. I think this is going to be a nice bow for a new shooter. 40-45 lb?
Title: Re: BBO formula?
Post by: razorsharptokill on October 12, 2009, 01:07:00 AM
Got the pic thing fixed. Here's a couple.
(http://img.photobucket.com/albums/v42/keyman/bows/CIMG0001.jpg)

(http://img.photobucket.com/albums/v42/keyman/bows/CIMG0002.jpg)
Title: Re: BBO formula?
Post by: Okie 1 on October 12, 2009, 08:01:00 AM
Lookin good Jim.
Title: Re: BBO formula?
Post by: razorsharptokill on October 17, 2009, 05:52:00 PM
Just shot it a bit. It draws 45 at 28". I have room to pike it. What do you think? Leave it?
Title: Re: BBO formula?
Post by: Dano on October 17, 2009, 05:56:00 PM
I'd leave it, never hurts to have a light bow around, you may get old some day you know.   :bigsmyl:
Title: Re: BBO formula?
Post by: sticshooter on October 17, 2009, 06:43:00 PM
I already know I am going to like this bow. Love that handle shape.<><
Title: Re: BBO formula?
Post by: razorsharptokill on October 17, 2009, 08:54:00 PM
It 68" long. How much weight would I gain by piking It? What are the down sides?
Title: Re: BBO formula?
Post by: Dano on October 17, 2009, 09:09:00 PM
You'd gain 3 or 4 pounds per inch. At your draw I might take it to 66" and see how she shoots.
Title: Re: BBO formula?
Post by: razorsharptokill on October 18, 2009, 04:16:00 PM
Ok sounds good.
Title: Re: BBO formula?
Post by: razorsharptokill on December 01, 2009, 09:47:00 PM
Bow went to a 12 year old boy. I heard from his dad that he loves it.
Title: Re: BBO formula?
Post by: Dano on December 01, 2009, 10:25:00 PM
COOL!!   :thumbsup:
Title: Re: BBO formula?
Post by: Stiks-n-Strings on December 01, 2009, 11:29:00 PM
that wood combo is sweet!