Primitive Archer
Main Discussion Area => Bows => Topic started by: Julian on March 22, 2018, 01:18:35 am
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This bow I'm working on is a kind of american longbow / pyramid bow / mollegabet hybrid.
(https://i.imgur.com/3OTb5MM.jpg)
I've finished the starting profile, and I have a question about the order in which to do things.
I want to back this bow with linen, as it has a bit of planer snipe on the back, and I also want to heat treat the belly and hopefully induce some reflex. Obviously I should wait to back the bow until after I'm done with heat treat, but how much tillering should I do before I do this stuff? At the moment the bow is floor tillered.
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I usually do my heat treat once I get the stave braced and evened out. That way you should have minimal belly cell damage and the limbs are thin enough you can easily get the limbs to temperature for a good heat treat. Then I would add the backing after heat treat but before continuin much further. Though I will frequently take the stave to nearly full draw before adding the backing to be sure it can handle the stresses on its own, then Add the backing for reassurance.
Hope that helps a little
Kyle
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Sounds good kyle, thanks.
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Looking good, make sure you post all the minor details. Id like to try that one day.
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I heat treat somewhere between floor tiller and brace height.
If you aren't going for a LOT of reflex, allow me to suggest toasting the bending portions flat and straight, and putting the reflex right at the base of the levers. For some reason doing it this way has always seemed to make it easier to tiller and keep the profile throughout the tiller.
I have set the limbs forward slightly at the handle to create a couple inches of reflex, but that seemed to complicate getting the inner limbs to bend evenly. Like they were stubborn right off the fades, and when I go that fixed, then they acted too stiff closer to the transition, and took more set both bows I made.
It worked better when I tried reflexing the levers into a smooth gradual curves, (again about 2"), but that also made the "outer" inners want to bend too much, and seemed to add some lateral instability (vibration at release).
My best mollies had the whole middle, handle and bending limbs straight and flat as a board once tempered, and just a slight angle forward built right in at the transition, again 2" or so. If you have the width, the middle will take almost zero set.
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Oh, and BTW, if you want, you can only back the inner limbs with the linen and finish with a nice binding at the transitions. The outer limbs hardly bend and would have to be all chewed up to need the backing.
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If you aren't going for a LOT of reflex, allow me to suggest toasting the bending portions flat and straight, and putting the reflex right at the base of the levers. For some reason doing it this way has always seemed to make it easier to tiller and keep the profile throughout the tiller.
That sounds good, I'll give it a try.
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First question....what kind of wood is it?.....
Second question .... why do you want to back it with linen , and what does "bit of planer snipe on the back" mean".... does it need it?
Again why do you want to " all of this stuff" to it.?
What design is the wood telling you to do?
DBar
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I tiller as far as possible before heat treat often as far as 24 inches. You run the risk of getting a bit of set developing doing it that way you could argue (quite rightly) but if I get any inkling it's going that way I normally put a bit of reflex in as I am heat treating too and it doesn't ever seem to affect the bow performance significantly and 9 times out of 10 much of the reflex stays put too. Otherwise I think you are scraping off much of the best heat treated wood in finishing off the tillering. I have found linen can go on late or even after it's tillered too so no problem there
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Danzn: "bit of planer snipe on the back" probably means he nicked or slightly shaved in to the top growth ring while removing the bark.
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Danzn: "bit of planer snipe on the back" probably means he nicked or slightly shaved in to the top growth ring while removing the bark.
No, This is from a slab.
There are nicks in the back from when the slab was put through a thicknesser at the sawmill.
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First question....what kind of wood is it?.....
Second question .... why do you want to back it with linen , and what does "bit of planer snipe on the back" mean".... does it need it?
Again why do you want to " all of this stuff" to it.?
What design is the wood telling you to do?
DBar
It's sugar maple, from a board. The growth rings run perpendicular to the back of the bow. I want to back it with linen because I want to paint the back of the bow and it's a good paint bearing surface, and also because as I mentioned, there's little gouges in the back from a thicknesser machine at the sawmill, and I'm not sure I want to sand down the whole back to take them out.
I'm making a molle because I've already made a flatbow and a longbow from this slab and I like variety.
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So I decided to start making some videos on this bow, because I've always wanted to try that, and I figured why not.
https://youtu.be/btReoVTPqX8
So here's part 1.
If there's any rules against posting your own youtube content here let me know. It's not monetised at all so I don't see the issue.
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I'll keep an eye out for the vids.
BTW, did your other slab-staves have the same kinds of nicks?
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I'll keep an eye out for the vids.
BTW, did your other slab-staves have the same kinds of nicks?
Yes, to a lesser extent. I tried to avoid them in layout. On my flatbow I planed them off with my block plane.
(https://i.imgur.com/YLz0OuY.jpg)
Here's what the nicks look like, incidentally.
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I see. Overbuild if you can, back it if you must. Good luck.
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I've gotten the bow tillered to 40# at 24" and I'd like a little insight into why I see such a difference between these two pictures:
(https://i.imgur.com/Fk0EGtO.png)
Here I am drawing around 24" in the hand
(https://i.imgur.com/nGK2V1K.jpg)
And here's the bow at 24" on the stick.
The first pic looks pretty good to me, but in the second pic it looks like the left limb is a bit stiff, and that the top limb is almost hinging out of the fades.
thoughts?
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If you look at the live draw (top pic) you are taking the pressure on the heel of your hand and it looks fine.
In the second pic you are supporting the bow where the web of finger and thumb would be.
The string must also be pulled from where your two main fingers will be pulling, otherwise it gives a false picture of the tiller.
With those shaped grips you sometimes need a little block of cork or rolled up rubber etc between the grip and the tiller block to get the bow to sit right (as it would in the hand).
Del
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If you look at the live draw (top pic) you are taking the pressure on the heel of your hand and it looks fine.
In the second pic you are supporting the bow where the web of finger and thumb would be.
The string must also be pulled from where your two main fingers will be pulling, otherwise it gives a false picture of the tiller.
With those shaped grips you sometimes need a little block of cork or rolled up rubber etc between the grip and the tiller block to get the bow to sit right (as it would in the hand).
Del
Thanks Del, that makes sense.
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Julian,
What counts is bow in hand...You look balanced in the first picture...Set your "nock point" and pull from there and take a second look...Your draw hand looks low...JMHO, could be camera angle though...I agree with Del on low heel pressure also...
Don
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Here's my third video on this bow.
You can see me pulling it in its current state near the end, that's where I took the still from.
https://youtu.be/td2MZiQIBwM?t=2m11s
let me know what you think; I'm very new to this.
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Nice work Julian.Like said changing position of hands affects tiller.Taking it slow is the key like your doing.Unbracing at times to check for set also.Sounds about right poundage for maple but did'nt get the length this bow was.A pulley system where you can stand back and look could help you.Right on that post your using in fact.
Good advise prior too.Looks like you got a shooter.
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Looking good.
Put 30-40 arrows through it. Then full draw vids again, maybe with arrow.
If you can, locate camera in line with your body and at belt/chest height.
Congrats!
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Sounds about right poundage for maple but did'nt get the length this bow was.
It's 67" t2t
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That's pretty decent poundage for such a narrow maple bow. You work pretty fast and it looks like you have a pretty good eye for this.
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That's pretty decent poundage for such a narrow maple bow. You work pretty fast and it looks like you have a pretty good eye for this.
Thanks!
The bow took more set than I would like, probably 2.5", which I'm chalking up to the narrow limbs, but I don't mind.
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Here's another video:
https://youtu.be/1oDrhh6QxUU
Since then I've finished the bow and put on the handle, wrapped the tip transitions etc. I'll take some photos and put them here :~)
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(https://i.imgur.com/S2tyaoT.jpg)
Braced
(https://i.imgur.com/yXnCNvl.jpg)
Handle
(https://i.imgur.com/Rq8YapR.jpg)
Unbraced
(https://i.imgur.com/Acv7usT.jpg)
(https://i.imgur.com/yH4VuWV.jpg)
More handle detail
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Nice work Julian. That looks like a great bow.
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Nice & clean Bow! What material is the backing-strip and what's the poundage?
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Nice & clean Bow! What material is the backing-strip and what's the poundage?
Linen, and its 45# @ 28"