Primitive Archer
Main Discussion Area => Bows => Topic started by: simk on May 28, 2019, 06:23:59 am
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Hi All
Last night I was dreaming about directly cutting out a d/r profile out of a edge grained piece of wood. Is there a chance of success or will it immediately break due to grain violation?
Cheers
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Make sure the side grain is parallel to back and belly too. Jawge
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I don't think that would work unless you do as George suggested and have the grain running with the back and belly.
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Thanks for the helping thoughts. I will probably not do this.
As an edge grained bow still is on my list, allow me one more q: You suggest that "grain is parallel to back and belly" Now: how can I detect the vertical flow of the grain on an edge grained stave? How can I make sure to have the grain parallel to back and belly? Do we have visible signs in the wood or is it just guessing??? Building a normal bow we obviously have the rings to follow the grain, but on an edge grained stave....???
Thanks again for helping a novice... (-_)
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No expert on this topic by a long shot, but your radial grain would be a mess. That run off on the edges would kill it I think.
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No you can't do that.
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Thank you Slimbob and PatM! Probably I should have made myself clearer about my still remaining question marks on edge grained bows. Again: I will no try to cut out an r/d profile that way. But if you do a "normal" bow of an edge grained stave: How do you I detect the vertical flow of the grain on an edge grained stave? How can I make sure to have the grain parallel to back and belly? Do we have visible signs in the wood or is it just guessing?? Thank you so much!
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cant be rift sawn. if it was a HUGE tree and had a ring chased like that, it would be flat and it might work.
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deerhunter1: I have a 2,5" thick board from a 25"dm ash, picked myself at the sawmill, perfectly edge grained on both sides (not in the center of course). I mainly bought it to cut backings but then had this idea...that's why I asked. So YOU think it could work??? Interesting.
Thinking edge grained is just completly different and unusual...at least for me.
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I try and relate it to a split edge.
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It won't matter how big the tree is. The grain structure still runs in less visible lines on edge grained material. You must be getting some erroneous ideas elsewhere and some on here too.
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I dont know, actually. In a perfect world yes it would work, in ours, not a great chance. Pats right, i completely forgot about the grain for a moment, im still a begginner 8).
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Thanks for the helping thoughts. I will probably not do this.
As an edge grained bow still is on my list, allow me one more q: You suggest that "grain is parallel to back and belly" Now: how can I detect the vertical flow of the grain on an edge grained stave? How can I make sure to have the grain parallel to back and belly? Do we have visible signs in the wood or is it just guessing??? Building a normal bow we obviously have the rings to follow the grain, but on an edge grained stave....???
Thanks again for helping a novice... (-_)
The same way people follow the grain to some degree on the sides of a bow limb, especially a snaky stave. There's lots of signs.
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Dont know if it answers your question but i when i had a thin piece of osage id saw the profile out and then sand the sides smooth i.would pick a ring i wanted to chase and then with a pencil i would draw a line all the way around the stave to see where that ring ran from end to end
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I was seriously considering a Edge grain bow from this one. I let my buddy practice chasing a ring instead. I've never tried one. The piece of wood your looking for needs to split the shape of a five curve. The stave I showed picture of I would've tried either a highly reflexed design. Or a deflex out of handle and tried to steam in a reflex mid limb to the outer. I have know idea if it would have worked
Bjrogg
Ps you might be able to steam in the shape your looking for but you need your grain to follow the bend. You can't just cut it to the shape you want. That's a pretty tricky design in the first place.
Bjrogg
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I'm sorry after looking at your drawing again I see it's a deflex reflex design. Not a five curve. In that case I would have tried to use the stave I pictured as a deflex out of handle and steamed in reflex. I would have thinned to closer to bow size first. I still have know idea if it works
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I dont think it will work. But if I were to try it, I'd back it with hickory or bamboo. I still think the belly will fail under sheer. The sheer stresses will make the violated grain slip against itself making the glue line to delam, then boom... just my opinion.
Dont let that discourage you however, if you have the time, material and interest, go for it! Just wear safety glasses.
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You could not cut it out you'd have to bend it to that, which sounds pretty impossible. Jawge
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Hi Folks
Thanks for contributing ;D
First of all I'd like to mention, that my quick and dirty drawing was completly exaggerated...the idea was a mild r/d with max 2" deflex/reflex over a bow of 65" - not some kind of scythian bow ;)
But regardless of that idea edge grain to me seems very strange and different (and interesting) in many ways.
Yes, there must be a grain flow but: You do not have the layers of early and latewood...the wood is acting much more homogenous.
Now, what does that mean for bow building? Can you tiller it also from the back? Probably yes. Probably the back must be less critical than on a normal bow. I heard they cut bombproof edge grained backings, obviously unable to really follow or care about the flow of grain. When do you violate the "back", what's the "back" and where would it exactly be on an edge grained bow? Is it maybe where the stave splits? How important is it really? The mysteries of edge grain (A)
Why are they not built more often?
Cheers
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Hi Folks
........
Why are they not built more often?
Cheers
Because it is much more difficult to get a clean back (unviolated fibres).
Your idea of cutting out that profile of a wooden block will cause a lot of left over firwood. And it is a lot of work. Why not go the easy way: chase a ring and steam the stick into the profile you like
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Thank you Simon. It's not anymore about cutting out that profile. It's about edge grained in general. Therefore allow me to penetrate: What's the "back" and where would it exactly be on an edge grained bow?
Further: On facebook i recently saw a 150# elb out of exotic wood with an edge grained ash backing. This backing was just cut on a circular saw, regardless of any virtual back or grain. I found that impressive and its also against your theory that it's "much more difficult to get a clean back (unviolated fibres)". DC also wrote that he uses edge grained backings for his bows, and so is Marc i think. How do they make sure to have unviolated fibres on the back? I just bought a big fat ash board to cut backings from...did I miss something?
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Like I said earier, I try to orient the surface I want to use to a split face. If you look at the picture the right side of the board is a little wavy. When I got the board the edge grain was perfectly straight. There was a drying check down the face you are looking at. The drying checks follow the grain so I split the board along the check. I think this board came from the butt of the tree because it flared out some. When I split it the split was curved. When I wanted a backing strip I scribed a line about 1/4" in following the split face. Sawed it of on the bandsaw. Then I ran it through my thickness sander. Sanded it down to 1/8". The heat from the sander seemed to straighten the strip some. When I need more strips I always work from the same face. I'm not sure if this was a good idea but the strips have help up. Hope that explains what I do.
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That is very interesting and helpful DC, thank you (just didn't catch your short version). Did you try the cheap way to just cut...? Is your method state of the art or perfectionism ;D
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I did try the cheap way and it worked fine. The board is 4' long and I was very careful to cut of the end with the runout. The board is Hard Maple and my tablesaw just smoked and squealed trying to cut it(it's an old worn out saw). I decided to use my bandsaw. I figured if I was using the bandsaw I might as well follow the grain.
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There is a difference between edge grained selfbows and backed bows with an edge grained backing. No the backed bow not only the backing is an important thing, also the glue line.
I've made some edge grained selfbows (tried to follow the grain as good as possible) in the past, but found no significant advantage. The wood is stiffer that way, but tends to get more set. In my eyes the wrong way ...
Edge grained backings:
IMO (when sawn with cirular saw): try to use highly interlocked grain wood, like elm, carpinus betulus, hickory or some species of ash. Make the backing thin (about 2mm). So the function is more prevent lifting splinters from the main/core wood.