Primitive Archer
Main Discussion Area => Bows => Topic started by: Caius on March 30, 2011, 06:25:54 pm
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K so here is whats left of my 80" maple...
Is the tiller looking straight? I can't see any major problems, other than the fact that its at 30#@13" in the pic.. Long string. Aiming for 40#@(longest draw possible 54.5 NTN)
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From the picture it looks good with the long string but get it on a short string as soon as you can and you will have a better idea of what the true tiller will look like.
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When do I put it on the short string, and how short do I go on it?
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I usually get it on a short string when I see both limbs are bending evenly have it bending about 14 to 16" at the target weight and when you brace it dont brace it more than about 4 inch brace height to start. For a bow like yours make the string about 2 " shorter than your knock to knock measurement and I belive a recurve should be 4". Someone will correvt me if im wrong. Check out this thread I follow this with my bows since I found it, it is one of my favorite build allongs ;D. http://www.primitivearcher.com/smf/index.php/topic,4815.0.html
Josh
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look's like you're long string is to long, get about an inch short of the nocks, then go 3" or 4" and go slow exercise it a bunch, i count every 3rd and count to 25, don't think ya can exercise it to much, good luck, Bub
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K so I got an even tiller, 40#@20" on the short string.. Its getting really thin so should I take the width down or keep thinning? And it was perfectly straight until I started to tiller, now the bow has started to twist slightly :s
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the twist is probably due to uneven wood remoavl on the limb
look at both side of each limb,are they the same thickness on both sides of the same limb?
how short of a string is it on?
are you at full brace height with it?
if not you need to get it here yet,then you will see the TRUE tiller and draw weight
if you already at full brace and its pulling 40# @ 20"
then that should be about (just swagging it here) 64# at 28"
how long is it from tip to tip now?
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the twist is probably due to uneven wood remoavl on the limb
look at both side of each limb,are they the same thickness on both sides of the same limb?Oh yeah, big time :/ gotta fix that.
how short of a string is it on?50"
are you at full brace height with it?Yes? 5.5"
if not you need to get it here yet,then you will see the TRUE tiller and draw weight
if you already at full brace and its pulling 40# @ 20"
then that should be about (just swagging it here) 64# at 28" I'm aiming for just over half that :/
how long is it from tip to tip now?56.5"
Cheers!
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Take it nice and slow dont rush at all durring this point of the process and make sure to exersize as bubby said after each time you remove wood ;)
Josh
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well first thing your gonna want to do is get them limbs the same thickness side to side
and definatly go slow and excersize it well
i wouldnt recomdnd just scraping untill you think it looks like they are the same thickness
take 15-20 scrapes on the strong side of the limb and excersize it well and recheck the twist
it can come untwisted quickly and you dont want it to go the other way on ya
good luck ;)
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K well I've been doing what I was told.... Still its not straightening out :/ Is the wood twisted or am I doing something wrong?
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sometimes i find it works best to just leave the bow strung for a few hours after scraping it
and then check it and see how the twist is
you are taking wood from the strong side(thicker) of the limb right?
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Yeah I have been, but to me, it seems like the thicker side is curving more than the thin side, might be me being retarded. How long should I leave it strung?
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well the last hick bow i made startd doing the whole propeller twist
i would scrape and excersize and it didnt seem to change
so strung hte bow and just let it si for a couple hours
then unstrung it and let it sit for a couple hours
then restrung it and excersized it quite well and i then noticed the change
good luck
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The main thing you need to do is keep your limb thickess the same side to side, if you have a set of outside calipers that will help you out. Sailordad knows his stuff so do what he says, also is there a slight twist when the bow is unstrung or not being drawn? Some propeller twist isnt going to hurt the bow as long as your thicknesses are good and the limbs are working evenly, you might notice a bit more hand shock but it should shoot just fine.
Josh
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Awesome help guys, I got one side a little thick at midlimb that I just noticed, so Im going to thin that down a bit and then exercise and leave it strung for a bit. I did check and the string is still running straight across the center line.
Thanks so much for the help guys!
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If the twist is natural I leave it alone. If I caused it by uneven wood removal then I fix it. It will always twist towards the weak side. Remove wood from the other side. Regarding when to string it with the short string, I usually long string tiller out to 10 inches of string movement...not tip movement. I check weight and look at the tiller. When the weight is equal to or slightly greater than target weight at 10 inches I string it up. There are buildalongs on my site. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/
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As mentioned, the truth will be told on a short string. Just take your time and work your way down.