Primitive Archer
Main Discussion Area => Bows => Topic started by: stuckinthemud on May 23, 2019, 02:00:25 pm
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Am on the short string, nearly at full draw, not sure if right side is a little stiff? Anyone else stretch elastic bands to keep an eye on limb balance?
(https://stuckinthemudsite.files.wordpress.com/2019/05/20190523_2115386844874851194837648.jpg)
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I can't see much to pick at. Looks like you've got it bending pretty darn even.
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If I really had to try it might be bending a bit much on the left just as it gets over the grass but it could just be shadows.
I have fiddled with elastic like that but I was lining it up with an arrow. I would put a mark on the elastic by the nock point at brace height and then make sure the mark followed the arrow as I drew it back.
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Looks good stuck. maybe make that right side the lower limb...
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:o that looks insane! what are you aiming for? I love the vice/tiller tree jig.
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Elastic bands? That's interesting and I can see you are strong on the right side...Might be hard to see otherwise...Nice tip and idea, I get it...
Don
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Yeah, right looks a tad strong.
Where is it supported? Looks like it should be supported where the cross is marked, but it looks like the weight is being taken on peg to the right of the cross?
Del
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The base of each peg is parallel and the bow is rubbing against each peg, but, the tpp of the one peg is knocked out of line, probably be worth my while to replace the paor of pegs with a single support all the same.
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Yeah, right looks a tad strong.
Where is it supported? Looks like it should be supported where the cross is marked, but it looks like the weight is being taken on peg to the right of the cross?
Del
Agreed.
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How's it looking now? Maybe a bit to come off the outer right?
Single support,, just for Del >:D
(https://stuckinthemudsite.files.wordpress.com/2019/05/20190524_2113324126040762692111946.jpg)
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Looks pretty good, hard to see any obvious error. It would help if we could see the entire sting and how the point that's being pulled relates to the rest of the bow and how it lines up with the point of support.
Gimme a pic and I'll draw pretty lines all over it :)
Del
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It is working just in the middle. On full draw its limbs will be stiff and middle working too much. You should change it. :(
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Here ya go... could be a bit more rounded.
Del
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Thanks guys, I think its looking a lot better now
(https://stuckinthemudsite.files.wordpress.com/2019/05/20190525_152817354586540143959078.jpg)
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OK, so I really messed up. I mounted the lath onto its tiller (its a crossbow) and found that I had mis-remembered the draw length when tillering and it is 2 inches shorter than the draw length I tillered the bow out to, this means that the 110 lb bow is shooting at 70. I like the reduced draw weight as it is really comfortable to draw where the 110lb draw is as much as I can deal with but then the performance at 110 is great but at 70 is pretty anemic. I can only pike about a 1/2 inch off the length of the bow, I could add another layer of sinew, I could even dare to attempt to heat treat the bow but there is a high risk of cooking the sinew, my son suggests building a new tiller and a new lath and having two crossbows for the price of two....What would you guys do??
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Add a belly lam!
It won't take much extra thickness, if you add 1mm that will prob' be plenty. Might need to flatten the belly first and then add say 3mm
Don't even think of trying to heat treat. You won't get enough heat without cooking the glue and sinew.
Del
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I'm liking your sons idea, but Del is the Man. Either way I'm really interested in this build. I keep thinking of building one of these just so I can tell some of my wheelie bow buddies that hate the crossbow hunters because they aren't shooting a "real bow"lol. Keep up the nice work and I'll be watching (-P
Bjrogg
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Belly lam sounds like a good solution. Just started a blackthorn bow, think I 'll harvest the lams from that. Would you take the opportunity to glue in a little reflex?
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Belly lam sounds like a good solution. Just started a blackthorn bow, think I 'll harvest the lams from that. Would you take the opportunity to glue in a little reflex?
Nope, I wouldn't add reflex, it's prob hard enough to brace anyway, and will that just be adding new problems?!
Mind, if the draw length is now less than you have pulled it to before you could add maybe a whisker.
Also as it's sinew backed it could be good. You need some of the sinew guys to chip in.
Del
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Blackthorn wasnt good enough, found a nice piece of apple the right size