Primitive Archer
Main Discussion Area => Bows => Topic started by: RyanY on July 08, 2009, 07:13:55 pm
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Been waiting to make a holmegaard bow for quite some time and am very pleased with the way it came out. 53" ntn approx. 50#@27". Made from hickory. I finished it with an ebony stain and painted on the designs with spray paint by cutting the design out of tape. The stripes on the wide part of the limb are two symbols on the korean flag. Three solid stripes means sky and the three broken stripes means earth. The other patterns are just for looks. Also, just in case, this is my bow of the month entry for july not the really tiny bow I made. Opinions please. Thanks.
(http://i327.photobucket.com/albums/k455/ryoon4690/CIMG2364.jpg)
(http://i327.photobucket.com/albums/k455/ryoon4690/CIMG2365.jpg)
(http://i327.photobucket.com/albums/k455/ryoon4690/CIMG2366.jpg)
(http://i327.photobucket.com/albums/k455/ryoon4690/CIMG2367.jpg)
(http://i327.photobucket.com/albums/k455/ryoon4690/CIMG2368.jpg)
(http://i327.photobucket.com/albums/k455/ryoon4690/CIMG2369.jpg)
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Photobucket was being sketchy so they photos are weird. Sorry.
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Very nicely done! A fine example of Holmegaard tiller. How much set did the bow take?
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Nice Job, I like! Board or stave?
Tom
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i like it, dude, i love holmegaard bows
how wide are the bending limbs? looks like maybe 2.25?
radius
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Very nice. Good Holmegaard full draw.
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I haven't measured it but I looks like it took around 3" of set. It is made from a stave I cut down from my back yard. The limbs are 2" wide. Thanks for the comments. I just glued up three laminated blanks for 3 english longbows I hope to make in incriments of 20# starting at 80#. Wish me luck.
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Here's a bow I missed for July. Sorry. I surfed back through the threads after I got back from a camping trip but still missed it.
Its a dandy, too, and is now up for August Self Bow of the Month
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l dont remember seeing this one. That bow looks really nice and l like the way you painted that design on it. Great Job.
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looks very good! Great job.How does it shoot? God Bless
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Really sharp. Perfect timing for me too, I'm in the garage starting to tiller one now. Gives me a good heads up on how to see tiller. Well done, thanks.
Parnell ;D
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Very nice bow!
Full draw looks good!!
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really nice bow, lad!
greets
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Thats a beautiful bow! I can't wait to try one.
Trey
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That's really nice. Well done. Jawge
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I got to see it in person at Mojam... :)
It's a HECK of a nice bow. Ryan is a very talented fella...
(oh, and a nice guy too as well as his dad ...)
Hi Guys...
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Sweet looking bow,nicely done. :)
Pappy
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I also missed this one, congrats on yer holmie :)
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nice job on that holmegaard!
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Wow....I was on Vacation in The U.P of Michigan and almost missed this Bow all together! Really nice representation of a Holmegaard Bow....I really like the whole thing...cant really see the Grip...but the Tiller....Shape....and especially Paint Job...is A-1 in my book
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Muy bueno, Holm-boy!
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Thanks a lot guys. I really appreciate it. (^_^)
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That's a nice one! It must be really fast.
Ryan sent me a PM about this bow, and I thought I'd just as well answer some of the questions here:
Good to see the outer limbs also bending a little, to make them as light as possible :) Even in such a bow, all the wood except the handle should be stressed equally, and I bet this one isn't far from that. If the outer limbs are as stressed as the inner, they won't take as much stringfollow as the inner parts of the limbs, because they are thicker. Heat treating the outer limbs would definitely be as important as treating the inner parts of the limbs. - both for making them stiffer to be able to shave of more wood, and to prevent them from gaining string follow. Be careful in giving the outer limbs too much reflex though, because they easily become unstable.
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I don't understand how you can say that the outer limbs are bending! They're completely flat and straight, which means they're not bending... as it should be with Holmegaard tiller. Can you please explain??
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I do agree with adb that the outer limbs on my bow are not bending but the advantage to having the outer limbs bend extremely slightly is not to get the wood working but to get the limbs as light as possible. Although the limbs will bend ever so slightly their remaining stiffness will still act as a lever. Sorry adb but you can't argue with a guy who has made world class flight bows from this design. While in traditional holmegaard design the outer limbs remain stiff, I believe kviljo is looking for more cast in the design. Are you arguing that the fact that having the outer limbs bending ever so slightly is a disadvantage to the design?
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Yes.
My previous question was more directed at kviljo.
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I understand. If I wasn't in school right now I would love to try and make two holmegaard style bows, identical in draw weight, draw length and wood species, one that has nonbending outer limbs and one with slightly bending outer limbs and see which performs better but I can't. I think that's the only way to end this argument.
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It seems the competing philosophies on Holmies surrounds the issue with the outer limb levers. One side says they should not bend at all so that they get max leverage and the other side says they should bend ever so slightly in order to reduce critical mass on the outer limbs. One side figures you lose efficiency when the outer limb bends and the other camp says they lose efficiency when there is excess mass on the outer limb. In this case I feel they both are right. I see the logic on both sides and have been thinking about this since I am working on a Holmie of my own.
Here is MY solution: I am aiming for a 50# draw weight, so I am going to tiller the inner limbs to 55#. Then I will start thinning the outer limbs until they just barely "give" the least little bit. At that point, I go back to the inner limbs and shave off the last 5# of draw weight. With the lower poundage, the outer limbs should stop bending AND be pretty bloody close to the lowest possible mass.
There ya go. I am not offering this as a way to satisfy both camps as much as I want to build the most effecient and effective bow as humanly possible. Feel free to pick apart my plan of attack, it is all grist for the mill.
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I'm not sure if that will work the way you want it to but I'd like to see if it does and how that bow turns out. I was talking to Tim Baker a couple days ago about this argument and here's what he said.
tiff outer limbs increase arrow speed three ways:
1, Reducing limb vibration.
2, Decreasing string angle, for lower stack/greater energy storage.
3, Reducing outer limb mass.
Although most of a bow's lost energy leaves via limb vibration, likely only a few % of this is rescued by stiffer non-vibrating outer limbs. Reduced string angle saves some relatively small amount too. But by far the biggest savings in via reduced outer limb mass, partly because this reduces limb vibration also, and string stretch, which itself aggrivates allows vibration. General terms are used here because the best engineering minds in the field still don't fully understand the interinvolved dynamics at work in a simple stick of bent wood, a situation that make us wood bow guys happily amused.
In practcle terms, the best way to increase bow perfomance is by lightening the outer limbs. The best way to do this is by making them narrower, as narrow as possible without becoming unstable. The greater % of limb length narrowed the better, but benefits fall of quickly around mid limb, since only the outer limb is accelerating quickly. If severly narrowed they must be a bit thicker to keep from breaking, and if thicker they can't bend as much as mid limb without breaking, so they end up being not just much narrower but much stiffer. They don't have to be completely stiff. In fact if you added enough wood for that then outer limb mass rises past optimum.
If you can't take his word for it then you're making slower than optimal bows!
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Nice looking bow!!! What was the draw length and the poundage???