Primitive Archer
Main Discussion Area => Bows => Topic started by: danny f on June 02, 2012, 09:32:23 am
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hi there. started on my first bow recently. its an edge grain ash board bow. i just wanted some expert eyes to tell me what and were i need to remove wood. the pictures are both the same except i reversed the bow on the tiller tree. the tips are moving about 6" so i tried to put the short string on and i cant get it on, is it to early yet? i bought the string from an archery shop and told them the dimesions of the bow so the string should be the right size hopefully.thanks for any advice danny.
(http://i493.photobucket.com/albums/rr292/dfee82/P1040018.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1040019.jpg)
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What do you see Danny? Its better to learn than be told.
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It does appear you have forgotten fades. You may have a handle popping issues.
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Maybe this will help you see, Danny. Your arc looks pretty good. A little stiff at the tips, but that's what you want. Otherwise the bow will be whip-ended.
However, does is look to you like one limb is weaker than the other? You should have a tillering string. One that you can shorten, as needed rather than purchasing a string that may/may not be the correct length. The tillering string would be a "tool" that you can use for all of the bows that you are about to build.
Looking again, it looks pretty good to me. Are you using a bow stringer to bring it to brace height? Have you tried a low brace height? Is the bow too strong? Is that the reason you are having trouble stringing it?
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Looks pretty good to me so far. You should get a shorter tiller string. It should be only slightly shorter than the bow.
To me it looks like you could go to low brace but I'd shorten the tiller string and look again first. Those loooong strings will give you a false reading.
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cheers for the advice and the elliptical thing is great to check out i could do with learning how to do that with my pics. i havent put fades in yet as i have been following a build along on youtube and he doesnt do anything with the handle until the end. the design is a pyramid bow, . i dont have a tillering string i am just using a braided nylon line that i use for bricklaying, it has a fair bit of stretch though. i have just measured the string that the shop sold me and it is only 62" and it is fairly untwisted. it says on the packet 66". i will stop working on the bow now until i have a proper string and tillering string. the limbs are half an inch thick all the way down and just abit thicker at the tips does this sound about right. or do they need to be thinner. thanks danny.
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i have been and bought a long string and took this pic, the bow wasnt braced i just got the string as tight as i could which wasnt very. heres a pic. i think the right limb is bending slightly more.
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(http://i493.photobucket.com/albums/rr292/dfee82/P1040031.jpg)
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Looks good for now :) Put it on a short string so you get a braceheight of 3 or 4 inches. Don't stick with that long string any longer.
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It does appear you have forgotten fades. You may have a handle popping issues.
gotta agree with pearlie, if it pops you can go bendy handle or glue thin lam's together to get the thickness you want, Bub
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thanks, i have now managed to do it although the brace height is low at least the string is tight i will put it on the tree and have a look. also i might take the handle down abit as im worried it might pop off now :)
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i have give it a few more scrapes and and got it braced to 3" i have just checked the weight for the first time it is pulling 20 pound at 14". i am aiming for around 50 pound. and my draw is around 28", heres how it looks drawn to 14". any tips welcome, does the bend looks ok.
(http://i493.photobucket.com/albums/rr292/dfee82/P1040036.jpg)
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Hmmm, I think you are going to end up underweight.
IMO
At this stage you should be pulling to about full weight and looking at the tiller as you slowly tease it back and remove wood to increase the draw.
I think you need to gradually pull harder and harder, carefully watching for any assymetry or nasty surprises and try to get at least upto about 40# before removing much more. Give it plenty of exercise and come back in maybe 5# steps checking at each point.
Del
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cheers for the advice del, im wont be to bothered if i come in under weight as long as it isnt miles underweight. the tiller is more important to me at the moment. i have been to scared to pull it to hard incase it snaps. :-\, i have now drawn it to 18" and the left limb looks stiff. but im unsure of where to remove wood from, i would say probably mid limb. it is pulling 30pound at 18".
i have also braced it to 6"now. heres the most recent pics.
(http://i493.photobucket.com/albums/rr292/dfee82/P1040040.jpg)
(http://i493.photobucket.com/albums/rr292/dfee82/P1040041.jpg)
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I have been feeling all along that the left midlimb is a touch stiff. Do some scraping on that spot and try to get that limb moving alittle more. It aint off by much. Looking good!
I would also be afraid of the handle popping off.
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I agree with Stringman. I would do some scraping on that left limb - maybe in the mid limb area, out to about 7 inches or so from the tip and get it bending to match that right limb. Go slow and exercise the limbs about thirty pulls or so after each wood removal. I think you can ease up on your target draw weight, or at least pretty close to it. I don't like wooden glued up handles as much as one built up from tool leather. That leather handle will bend with the bow. Looks like it is coming along nicely! Draw a couple of horizontal lines on that plywood behind the bow and make sure that your limbs tips are bending evenly... Even bending is a biggy.
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Yup, left limb is much stiffer. Try feeling the thickness between finger and thumb as you run your hand along it. A pair of vernier calipers tightened at one point and then slid towards the tip while you watch the slowly increasing gap will also help find any high spots. Check spot thickness every 6" or so too, compared with the right limb. Although it's all eye and feel at that realy matters in the end.
I know how you feel, it can be scary, but the bottom line is you gotta pull it back sometime. I'm mentally saying 'bang' to myself a s I pull it back, so that if it does go bang it won't be such a shock! ;D
Del
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well i have got it to full draw now, i still think the left limb is stiff. i havent taken anymore of the right limb all day lol. how does this look, if it is not to bad i may leave it, and put the stiff limb on the bottom, as im well under weight, it is pulling 37 pound at full draw and i havent started sanding yet, i have now narrowed the handle and fades. in a way im glad im under weight as i didnt realise how hard to draw it would be. i need some training ;D
(http://i493.photobucket.com/albums/rr292/dfee82/P1040060.jpg)
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Right limb is working rather hard just out from the fade (there's a funny pale triangular mark on the wall above the dodgy area). Left limb is quite nice.
If you ease the left one off just a tad it will take some load off that right one, maybe just a whisker off the right limb, mid to tip again to ease the load off that spot just out from the fade. Evening out the tiller will prob still give you 35# whish can still bang out an arrow if it's well tillered.
But heck , if it shoots, quit while you are ahead.
Del
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cheers del, i have been out and done some more scraping, inbetween you sending the last post, these are the latest pics. i will go out and have a look at the right limb now. :-[. i though it was a goner before the tiller tree rope snapped scared the life out of me lol.
(http://i493.photobucket.com/albums/rr292/dfee82/P1040063.jpg)
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i forgot to ask, what do mean by ease the left limb off? thanks.
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(http://i493.photobucket.com/albums/rr292/dfee82/P1040064.jpg)
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Looks like a shooter! I may be wrong, but I think if you take your photograph from the same place and center focus right in the center of the bow, the true picture of your tiller will be more apparent to all your on-line mentors. You have done a good job, now go and fling some arrows!! ;)
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By 'Ease off' the left limb, I just mean scrape/sand it down a tad all over, so you just weaken it a little but don't change the tiller of it.
It's looking better now, it's amazing how just a slight change can make it look a lot better even though it would be hard to actually pinpoint the difference.
Tillering is all about tuning your eyes to those subtle curves and changes.... mind it can drive you mad! That's why it's best to step away sometimes and leave it overnight.
Del
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cheers for all the help everyone, i have decided to leave it that now, before i cause anymore problems. i will put pics on another thread when its completely finished, then onto the next lol. :)
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Good job! You fixed that tiller very well! It's a pity you've come in underweight, but it's a common beginners mistake. Been there myself for ages... Del the kitty has given you some excellent advice. He is spot on. I noticed that weak spot on the right limb as well, near that funny pale triangle on the wall. This spots still bothers me a bit. Please inspect it closely; is there a small knot, a chrysal on the belly, or a splinter ready to lift?
I can't judge from the pictures: have you rounded the corners on the back? I don't think you should change tiller anymore, but rounding the corners on the back is crucial. You'll loose only like 1 or 2 pounds, while it doesn't affect tiller (since you remove wood along the entire length of the limb). The rounded corners mean there's less chance for splinters to lift.
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thanks darksoul, i have looked at the spot and cant see anything wrong there. there are no knots or anything obvious. i have rounded all the edges off. i have got more sanding to do then i may have another look at the tiller again and maybe make some adjustments if it really needs it, thanks again for all the advice i have been given. :)