Primitive Archer
Main Discussion Area => Bows => Topic started by: Canoe on June 16, 2009, 04:33:36 pm
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Dear Abby,
I'm trying to build an ALB, for a friend, from an Ash stave; 48#@29-1/2”. (Yes, that's his actual draw length.) The stave's Total Length is 70-1/2”, and Width is 1-3/4" for 2/3rds of the limb, and it is stiff handled. (I'll try to get some pictures up soon.)
So far, I've roughed it out, floor tillered, and went to Short String – which I'm describing as a tillering string that is as long as the bow.
At this point, my intent is to continue tillering until I can get about seven inches of limb movement while still remaining a little below target weight. (At seven inches, I intend to attach the bow string – to string the bow.)
However, two important questions have come up;
First… I have pulled the limbs to five inches of limb movement. And, I equate these five inches of limb movement as 10 inches of drew length. Is this correct?
Second… Now, as I have pulled the limbs to five inches of limb movement, my digital scale is reading 34lb.s. If I am correct and that is about 10 inches of draw length, then I'm getting 3.4lbs per inch of draw. Am I overstressing the limbs? If so, how should I proceed?
(Yes, I know that's three questions, but who's counting?) Now, it's four questions. Cripes!
Thanks,
Confused (Canoe)
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Canoe....if the bow is bending throughout the limb you are probably ready to try and raise the brace height a little at a time until you get to a full brace height........remember too excersise the limbs and keep your tiller even until you hit brace height.
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long string tillering gives false weight readings (higher than actual weight). like Marvin said keep shortening the string till tillered at brace height, and dont worry about overstressing, just dont draw above the final target weight and you should be fine. your first 5 inches of limb movement is actually no draw length at all. seeing as most brace their bows from 4-6.5", just keep from drawing over target weight and all should be well. best of luck.
Dustin D
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I long string tiller to ten inches of string movement. Note that in a drawn finished bow the tips move at most a couple of inches so measuring limb movement if, done by tip movement is probably not a good idea. At ten inches I look to get 5# over target weight in the finished bow and good limb movement. This puts the stave at 10-15# over final target weight. Then I string it up and proceed. More on my site. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/
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Howdy Group, Marvin, Dustin, and George T.,
Sounds like I'm moving in the right direction.
George said, "... measuring limb movement if, done by tip movement is probably not a good idea." I'm assuming he means that to measure, or extrapolate a draw length from limb tip movement, during longstring tillering (which is below brace height), is not correct or accurate.
He also suggests longstring tiller out to 10" of tip movement, (not 7" as I had mentioned), where draw weight is above(?) final target weight.
And, Dustin said, "longstring tillering gives false (draw) weight readings (higher than actual weight)."
So, today, after applying a silk backing and letting it dry, I'll raise it to low brace height and tiller it out to 9" or 10" of tip movement with a draw weight near the target weight.
Sound good?
Thanks for helping to clarify this for me. And, I'll write this into my bowyer journal so that I can follow this same path on my next bow(s), (which are fastly approaching longstring tillering phase.)
(To Resize my photos, so I can post them, is continuing to be a challenge.)
Thanks again Group,
Canoe
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Canoe, if you have a PC, there is a program in accesories called " Paint". I use this for resizing. Open your file in paint, at the top under "image", select "stretch/skew" reduce to 25% and go from there. You just have to get the image down to 200kb.
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10 inches of string movement not tip movement. Stretch the string. Mark it. Measure down 10 inches. Mark it. 10 inches of string movement. Jawge
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Howdy Aosda and George,
Thanks for the info and clarification. I'll try to Resize my pic.s with "Paint" tonight or tomarrow, (when it's raining and I'm inside).
OK George, I'll go with string movement - thanks. BTW, I've been working on tillering three bows today! And, all three are nearly ready for their bow strings and are coming along nicely.
Thanks,
John Y.
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photobucket.com is a great (free) site to upload pics to, and they dont use P.A.'s bandwidth to store. i like it because you dont have to resize photos. just start an account, browse your comp from their interface to upload photos. once uploaded, mark the photos you want to use in the little check box and click the "Generate HTML and IMG code" button and choose either IMG clickable thumbnails for messageboards, or IMG images for messageboards. just copy and paste the link as shown to get this.
the thumbnail looks like
(http://i352.photobucket.com/albums/r327/myownslave/th_IMG_1372.jpg) (http://s352.photobucket.com/albums/r327/myownslave/?action=view¤t=IMG_1372.jpg)
^you can click it for a bigger image
and the IMG image looks like
(http://i352.photobucket.com/albums/r327/myownslave/IMG_1372.jpg)
hope this helps if you decide to go this way.
Dustin D
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Off topic, but that's a mighty nice looking bow Dustin.
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thanks Aosda that one is for my fiance (dont know if she will ever shoot it :( ). any luck on the image posting Canoe? let us know how it turns out.
Dustin D
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Howdy Group,
Dustin, George, Aosdia, and Marvin thanks for the encouragement and guidance.
Yes, I did finally get this bow tillered. It was a slow process, but now it looks pretty good.
The tiller does have some hinge to it. The tillering process proved to be an excellent learning experience.
And, I like this one. I'll be using it this Fall for hunting.
White Ash, 68" Long, 47@28", backed w/ silk
Braced to 7"
(http://i276.photobucket.com/albums/kk37/Canoe_2008/100_1140AshBraced4728.jpg)
Drawn to 25"
(http://i276.photobucket.com/albums/kk37/Canoe_2008/100_1142AshFullDraw4728.jpg)
And Dustin, I got that Photobucket account and up loaded a bunch of photos, but I'm still having trouble posting my pic.s... Oops.. Got it!
Canoe
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Very nice. Congratulations. Jawge
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glad to hear you got pics working, nice looking bow. looks a little stiff midlimb, might scrape a little off but your gonna loose some weight if you do. you know what they say, if it aint broke dont fix it.
Dustin D
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Well done. Glad you got it tillered. Your tiller doesn't look too bad, looks stiff on the outer limbs. If you haven't put an arrow rest on it yet, try getting someone to take a full draw pic of you actually drawing the bow. Take a pic with each limb as top/bottom. And go with which way the tiller looks best.