Primitive Archer
Main Discussion Area => Bows => Topic started by: Easternarcher on January 17, 2008, 05:31:18 pm
-
Guys, I got this BBO, 66" and I'm shooting for 55lb at 27 -28in. I'm afraid I may have screwed it up! :'(
At 6.75in. brace the right limb appears to be stiff, but it's only 1/4in less than the left side. I'm afraid to go any further without help cuz I don't wanna miss my weight, and it already appears that I've messed up the tiller at draw. I'd say for sure that i got it bending way too much out of the fades.
These pics are taken at 25 in. draw at 55lbs. Where do I go from here? Sorry about the pics, but I can't back up any further in this tiny shop.
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/fullriser.jpg)
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/leftlimb-rest.jpg)
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/rightlimb-rest.jpg)
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/leftlimb.jpg)
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/rightlimb.jpg)
-
I like the right limb better than the left. Left looks to be bending pretty hard in the first third (near the handle).
One thing I've observed, is that the BBOs tend to hold up pretty well with a less-than perfect tiller. So if you are concerned with having enough poundage, I'd simply stop and call it done when you run out of room. At 66" and a 28" draw, you're not near the limit of stress even if you have more focused on one region than another. I don't see any outright hinges anyway.
-
I like the right limb better than the left. Left looks to be bending pretty hard in the first third (near the handle).
One thing I've observed, is that the BBOs tend to hold up pretty well with a less-than perfect tiller. So if you are concerned with having enough poundage, I'd simply stop and call it done when you run out of room. At 66" and a 28" draw, you're not near the limit of stress even if you have more focused on one region than another. I don't see any outright hinges anyway.
No, I don't see any real hinges either, but it kills me to mess up like this! It seems I'm developing some bad tillering habits like scraping to much near the fades. It looks ugly tho! I still have a couple of inches to go too, wonder if I should creep along and get it alittle closer to draw lenght?????
-
I wouldn't say you messed up. These backed bows are kind of a different animal to tiller. There is a real tendency to have it bending too much near the fades. It really helps if you taper the belly slat and the bamboo backing prior to glueup. You get a lot smoother R/D profile this way too, with less cranking on clamps. And a lot of people put in a power lam either between backing and belly, or between belly and handle piece. I usually put a power lam between belly and handle piece, its easier to do. The power lam bolsters that inner limb and makes it easier to avoid the hinge near the handle.
You might be surprised to find how little amount of scraping it might take to round up that left limb. Once you get close, it gets pretty touchy. Thats good because you won't lose a bunch of weight making the correction.
One more thing, I recommend you photo yourself drawing the bow as a final step in tillering. A lot of times the tiller will look quite a bit different from the tiller tree, when it is in your hand and being drawn.
-
I wouldn't say you messed up. These backed bows are kind of a different animal to tiller. There is a real tendency to have it bending too much near the fades. It really helps if you taper the belly slat and the bamboo backing prior to glueup. You get a lot smoother R/D profile this way too, with less cranking on clamps. And a lot of people put in a power lam either between backing and belly, or between belly and handle piece. I usually put a power lam between belly and handle piece, its easier to do. The power lam bolsters that inner limb and makes it easier to avoid the hinge near the handle.
You might be surprised to find how little amount of scraping it might take to round up that left limb. Once you get close, it gets pretty touchy. Thats good because you won't lose a bunch of weight making the correction.
One more thing, I recommend you photo yourself drawing the bow as a final step in tillering. A lot of times the tiller will look quite a bit different from the tiller tree, when it is in your hand and being drawn.
Thanks Tom for the encouragement! I need it right now on this.
Well this does have a power lamb between the boo and the belly wood. I like a non-bending handle section.
Round up the "left" limb? I'm thinking that the right side needs to be rounded to match...Then take it to final draw weight...
I'll have to get a buddy to come over to do the pics at full draw on the weekend.
Thanks again.
-
OK guys/GAls, after 50 shots, this bow is holding 1/4" positive tiller.
In the braced pic, the left side is the upper limb. After initial sanding with 150 grit, she's pulling approx. 50 lbs at 26..5-27" draw.
Opinions? Should I work the right side limb or leave it be and finish her out?
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/FULL65INBRACE.jpg)
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/FULLDRAW.jpg)
(http://i179.photobucket.com/albums/w301/Easternarcher/BBO-JAN%202008/FULLDRAW2.jpg)
-
Fine looking bow for sure. Tiller looks smooth and even-bending in your drawn shots. I'd personally call it done.
-
I wouldn't change anything, looks good to me.
VB
-
Looks good to me,I would finish it up.Nice job. :)
Pappy
-
WooHoo! Thanks all!!! I'm thinking I'll finish it too and start another...Taking this one bunny hunting maybe in a couple of weeks.
-
Awesome! Jawge
-
Looks good to me also
-
I like it!!! But it looks to me like you are drawing the arrow on the wrong side of the bow?
-
Thumbs up!
If the arrow would be on the wrong side, wouldn`t it fell to the right side, because the bow is held with top tip to the right side?
-
I didn't notice that until uwe pointed it out, why is the arrow on the right side of the bow?
Tiller looks good to me.
-
Thumbs up!
If the arrow would be on the wrong side, wouldn`t it fell to the right side, because the bow is held with top tip to the right side?
Becuz of the angle, you can't see that it is actually on the left side of the bow sitting ontop of my knuckle. No rest! ;)
-
I have seen a very few people that shoot like that. Instead of off the knuckle, they shoot off the thumb. When they cant the bow over, just raise the thumb to keep it from falling. Looks like the fletchings would dig into the thumb.
-
Eastern,
Two things occur to me that I have done. One is that you can put it in a heat box on low heat and see if the bamboo may not be dry enough. I know that tiller often changes on BBO's that I have built, and I have built about twenty of them. Th other thing that works great is to shave the belly down and glue a thin laminate on the belly where it is weak. One of the best bows I have I treated that way, and it is a great performer. 186 fps with a 500 grain arrow. You can either glue a lam just on the weak spot or shave down on both ends and put the thin lams on and re-tiller.
Dirty Dan
-
Thumbs up!
If the arrow would be on the wrong side, wouldn`t it fell to the right side, because the bow is held with top tip to the right side?
Becuz of the angle, you can't see that it is actually on the left side of the bow sitting ontop of my knuckle. No rest! ;)
Thats what I thought. The knuckles hide the shaft.