Primitive Archer
Main Discussion Area => Bows => Topic started by: arachnid on June 26, 2014, 03:17:35 am
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Hi guys.
Just finished this WOBI (White Oak Backed Ipe :laugh:) flatbow.
It`s a pyramid design, tapering fro, 1 1/4" at the fades to 3/8" tips.
The interesting part about this bow is that I didn`t have accsess to a bandsaw, so
I had to cut the backing strips with a jigsaw! Very hard to do... but doable....
Anyways, I call it "Gunpowder", becaus the Ipe had a yellow powder coming out of it when I rasped it.
Its 66" TTT and pulls 45#@26". After sooting it for an hour it took about 2 1/4" of set (I think its becaus of the
white oak, I made a bit thicker then 1/8"). Riser is babmoo flooring and beech. tips are ipe and oak.
Tell me what you think.
Dor
Front:
(https://scontent-a-fra.xx.fbcdn.net/hphotos-xfp1/t1.0-9/10491984_643643505725377_7124375654371246037_n.jpg)
Riser:
(https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xap1/t1.0-9/10505542_643643729058688_2422590396219284811_n.jpg)
(https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-xap1/t1.0-9/10360462_643643759058685_2842949612618140979_n.jpg)
Braced:
(https://scontent-b-fra.xx.fbcdn.net/hphotos-xfp1/t1.0-9/10329021_643643685725359_4187003005780555724_n.jpg)
Full Draw:
(https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-xap1/t1.0-9/10352266_643643602392034_5729915963920958767_n.jpg)
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Tiller looks nice. Nice job. :)
Pappy
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Great tiller.
It has a slightly Art Deco look to it !
Del
Actually I once with a bloke called Art Deco!...
(sorry, no I didn't I'm just a baaaaaad kitty :laugh:)
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WOBI-tide anything that gets in front of that.
Cool bow.
http://en.wiktionary.org/wiki/woe_betide
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WOBI-tide anything that gets in front of that.
groan :laugh:
Del
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Arachnid, Like the bend on that one bud, don't worry about a little set...The cool thing is, you took what you had, used the tools you had and made a nice bow... Bet that's your best performer yet... 8)
Don
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WOBI-tide anything that gets in front of that.
groan :laugh:
Del
You groan not because you did not like the pun, but because you didn't get it out first!
Arachnid, You are the WOBI-Wan-Kenobi of that mix of woods! Good work!
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WOBI-tide anything that gets in front of that.
groan :laugh:
Del
...NOW THAT - was punny!
OneBow
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I'm curious about the shelf for a right-hander and you are drawing it as a left-hander. Merely curious...
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Jim, you must be reading this through a mirror!
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I think the overlay on the back at the handle area made that look confusing. It's a right handed bow...
OneBow
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Jim, you must be reading this through a mirror!
.saw I sseug I ,peY
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Nice looking bow man, how much thicker did you make that backing?
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The backing is 3/16".
I was wondering, how much set is acceptable?
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Arachnid, you had about 2" after shooting probably some of that bounces back after relaxing a while...The deflex thing is up to you...I've seen bows with deflex out shoot reflex...They say it makes for better accuracy/more forgiving? If your happy that's what matters, if it took 4-6" I'd say you lost performance for sure...Give us an unbraced side profile if you want...
Don
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Well, after shooting for a while the bow came down to 40#@26".
here`s the unbraced pic:
(https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-xfp1/t1.0-9/10348355_646477972108597_5593192718317440319_n.jpg)
here`s the set mesurment pic:
(https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-xap1/t1.0-9/10517519_646478012108593_2599766025739854425_n.jpg)
The bow is 66" long tip to tip. Do you guys think shortning it will help? Or it will take more set after shortening?
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You lost 5#? That seems odd. Yes, shortening it makes the remaining length work harder which makes more set. Id probably just start another and leave it be.
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You lost 5#? That seems odd. Yes, shortening it makes the remaining length work harder which makes more set. Id probably just start another and leave it be.
1) How many # usually get lost due to set?
2) I know that white oak takes quite a bit of set. How can I prevent that much set on my next bow if I`m going to use white oak as backing (we don`t have hickory around here)?
3) Will bamboo backing be better (I`ve never worked with bamboo before and I`d like to try. I just
want to know what to expect...)
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Honestly, I don't think I lose a pound after the first 15-25 shots. Unless the wood is "wet". Did you exercise the bow well while tillering? Your bow is plenty long for your draw. Did you glue in Perry reflex? Or did you glue it up flat?
Ive never used white oak for a backing, probably wont. I like hickory and hickory. So I cant tell you much about it. Boo on the other hand, Ive used plenty. I don't care for the prep time and explosive nature. Others have different results.
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I did exercise the bow well while tillering, about 30 pulls after every wood removal session. I glued the backing flat and it`s 3/16" thick (mabey it too thick?).
And, the weight lose is after about 100-150 shots.
About the length, I make my bows 2 times longer the my drew weight + 10-20%.
"Explosive nature"?! ??? ??? ???
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Sounds good to me. You shouldn't lose 5# after 100-150 shots. What state do you live in?
Boo has a tendency to pop splinters and let go quick, or, it stays solid as a rock for eons. I like hickory because I can see the woods quality and use it accordingly, boo is hit or miss and looks don't mean much.
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I just noticed something. You may have went too wide on this bow and eliminated too much ipe from the belly. That made the white oak work harder on the back and oak will take set easier than ipe will. Maybe try building the same exact bow, but 1" - 1 1/8" wide at the fades. That will allow much more ipe to stay behind.
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Could be... I`ll give it a go.. thanks PD, you really helped me on this one (BTW, I love your "Howerd" bow...).
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My pleasure. Enjoy it as is and get another cooking. Thanks for the compliment.
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Arachnid, you're definitely making progress with your bows! This one looks very good and shows a good tiller. It's balanced and well proportioned. A little bit of set never killed anyone, so don't get too upset.
However, it is important to find the cause for the set and try to learn from it. 2" of set is nothing terrible, but more than I would expect for an ipé belly. Remember that set is always happening in compression, so on the belly of the bow. I therefore I don't entirely agree with Pearl Drums, saying that "oak will take set easier than ipé". In principle it is true that oak tends to take set faster than ipé, but since the oak is only in tension in this bow, it doesn't take set in this particular bow. It would be a fun experiment to saw the bow lengthwise, along the glue line, and see what shape both wood species take. Wasteful, but a good learning experience.
I do agree with Pearl Drums about the idea that too much of the ipé on the belly was eliminated on the belly. However, I'm not sure that was caused by the bow being too wide. I personally think that 1 ¼" is a perfect width for the desired draw weight and - length. In my opinion, the cause for too much ipé being eliminated from the belly, is the thickness of the white oak backing. With the thickness of the backing being 3/16", you're going to end up with a really thin strip of ipé. The backing effectively "overpowers" the belly, and puts too much pressure on too little ipé. The best and easiest solution would have been to thin the backing, possibly even after you glued it to the ipé. You could have tapered it to 1/16" at the tip, but also an even 1/8" would have been helpful. On the other hand you could have made the bow longer, which also would have increased the limb thickness and thus decrease the stress on the belly. While Pearly's suggestion of a WOBI of 1" to 1 1/8" wide is perfectly feasible, you need to remember that you will then be making more of a longbow, instead of this flatbow. Just making the bow narrower puts of course even more pressure on the belly (and back), thus resulting in more set. You could make the bow narrower, but then it should also be made longer. That would require a more different design. If you like this design and want to stay as close to it as possible, you should shave off about 1/16" of that backing, resulting in more belly wood and less set.
Don't let this analysis take you down though. You've made a fine bow, and 2" of set is not terrible at all!
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Darksoul, thanks for the kind words.
I thought the thick backing might have been the couse, but due to my lack of a bansew, that's the best I could do. However, I Didn't thought about thining the backing after gluing (using a scraper, I assume?) and I'll defenatly remember this lesson for my next bows.
I there anything I can do to reduce set on that bow or whats done is done?
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It's strange that ipe would take that much string follow? It could be just the piece of wood. I've had straight hard wood bend like a banana after cutting boards from it. The white oak is not the problem! I had a hickory board just recently take 1 inch of deflex after heat treating the belly. I started out dead straight. 3/16" is not that thick for backing. Iv'e been going even 1/4" thick after splinters raised right through some 1/4 sawn x 1/8" hickory backing. cheers fiddler49
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What's done is done. Yes, a scraper coupled with a sanding black will reduce the thickness. I round my edges right over to.