Primitive Archer
Main Discussion Area => Bows => Topic started by: Wooden Spring on December 03, 2013, 08:50:03 am
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I just put the finishing touches on a bow that I'm building for a 14 year old's Christmas present. It's a 35# Red Oak Pyramid bow backed with 7oz canvas.
66"NTN
2" @ fades
1/2" @ tips
1/2" consistent thickness along limb.
On another bow, I tapered the limb thickness from 1/2" at the fades to 3/8" at the nocks, and the tiller was MUCH better than this one, so from now on that's what I'm going to do. The tips on this bow are really stiff, but it's a really quick bow for 35#... It took about 2" of set, but it shoots, so who cares, right? ;)
The pictures show the backing (not my best work, but it's functional), full draw picture, and my poor shooting skills at 25 yards on a 9" bullseye.
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Looks pretty good to me dude! Nice work. That young man is going to love it!
You like pretty serious in those shots....glad we're not enemies. :laugh:
...we're not right?
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Looks pretty good to me dude! Nice work. That young man is going to love it!
You like pretty serious in those shots....glad we're not enemies. :laugh:
...we're not right?
Oh, good grief... Well, it was cold and I was pacing to try to keep warm, and as my wife was taking the pictures, she said "hold still!" And I guess a grumpy face ermerged. That's why I look so serious I guess. Nah, the only enemy I have is Annie May, my Sea anemone enemy...
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Good looking bow! He'll be happy, and don't worry, lots of us shoot like that at 25 yards. ;)
Tattoo Dave
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Id need a bigger butt at 25 yards, that baby wont catch all my arra's!
Nice bow!
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You've done really well with that. With those stats and that design and your excellent tiller, I'm surprised it took 2" of set. If I was gonna be nit-picky, I'd say your mid to outer limbs are just a bit stiff. With a pyramid design like you have, ideal tiller should be a bit more round.
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Your tiller looks great. Who ever receives that puppy is going to be a happy kid. Nice work
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You've done really well with that. With those stats and that design and your excellent tiller, I'm surprised it took 2" of set. If I was gonna be nit-picky, I'd say your mid to outer limbs are just a bit stiff. With a pyramid design like you have, ideal tiller should be a bit more round.
The problem is that I haven't had a red oak bow yet take anything less than 2" of set...
I wish there was somewhere a detailed description of how one tillers a bow. I've got a BUNCH of books, and I love to read, but they never go into tremendous detail about tillering... Or maybe I'm just reading the wrong ones?
Yeah, the bow is stiff... The reason is that I've kept the thickness consistent throughout the length of the limb. I know that's what you're SUPPOSED to do, but in experimenting with about 8 bows of equal dimensions, if I taper the thickness by 1/8", from 1/2" at the fades to 3/8" at the tips, the tiller is almost perfectly circular.
Can someone explain to me how violating convention makes for a perfect tiller???
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Good looking bow,tiller looks fine to me. Shooting ant bad either. :)
Pappy
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I let the tiller determine the thickness. Yes, for pyramid bows the thickness should be pretty much even from fade to tip, but in the end, I don't measure it. I let the final tiller shape (I want) determine the thickness.
There are no rock solid tillering conventions. There are some ideal designs. Wood is a natural material with inherent flaws and characteristics. Tillering is not complicated. Believe what your eyes are telling you, have a set goal in mind BEFORE you start a build, and proceed with patience and diligence to arrive at your goal.
If I start out with a pyramid design, I'll floor tiller until I can arrive at a low brace, and then throughout the tillering process, I think round. Make the tiller round. I'll get the fades moving first, and then bring the tips around last so I don't end up whip tillered.
Reading good books is valuable, but it's like learning karate from a book. You can't... not well, anyway. Get your hands dirty (and you are) and experiment. Insanity is doing the same thing over and over, and expecting a different result.
Don't get me wrong, your bow is good, but with those stats and a good piece of wood, you should be able to do better with the set. Half that set would be ideal. I don't know about oak cuz I've never used it. Look at where your finished bows are taking set, and let it be a guide as to where the limb is over stressed. If your set is even throughout the limb's length... you're doing good. If it's all in one spot... you're not.
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like adb said, the even thickness taper is the starting line, but it probably wont be that at the finish, the wood will determine everything in the end, nice looking bow he should be thrilled with it, bub
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Read traditional bowyer's bibles and find some experienced bowyer next to you and watch them tiller or look at boarior bows on YouTube. He has good build alongs that help a ton. That is how I learned reading and YouTube :o ;D
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One thing about tillering different profiles still eludes me. Maybe someone could help me here. Its the way I understand wide vs. narrow limbs and how they handle different stress.
For example, on a lever bow, the levers are narrow and deep, because you don't want them to bend, much. And stiff handles, are narrow and deep, because you don't want them to bend. Tips are narrow and deep.
Wide wood is less likely to break than narrow wood that is thicker. So we make white wood bows 'wide' so they can bend and still handle the stress. Wide/thin wood bends and doesn't break.
So I get confused when I read in vol.4 how pyramids should be circular and parallel limbs eliptical. Its seems to me to be the other way around since parallel limbs are 'wide' in the outer and therefore can safely bend, making a more circular curve.
Pyramids are becoming levers in the outer limbs and should therefore bend less in the outer, more eliptical, because you don't want narrow wood bending as much.?
Can anyone help?
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Because most of the bending on a pyramid bow is a result of the profile taper, with the thickness remaining relatively constant, the ideal bend is even (or circular). On a bow with parallel profiled limbs there is no distal taper, so the limb will bend less towards the tips creating a more elliptical tiller. A parallel limbed bow must have thickness taper to bend.
One of my favourite statements to new bow makers... "Even tapers (thickness or profile) make even bends."
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So why ever have parallel limbs?
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I haven't made a bow with parallel limbs for years.
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So Meare Heathe is wrong because is violates the mass principle?
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Cool... :)
@Steve....no not really....as long as its narrow enough it doesn't...and you would need to adjust your tiller shape to a very elliptical tiller(almost whipped,but not really) that way your moving mass is moving in the right place,and will be as light as it can...make sense?
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When it come to choosing the right limb design, all the books I've read leaves out the "when". They talk about back profiles dictating the braced profiles, but more or less skip "when" these particular limb designs are appropriate. I think first, you have to consider side profile before deciding on limb designs of either pyramid, parallel or somewhere in between. The right design for draw length, bow weight, handle design, arrow weight, reflex/deflex , and back deformities (or not) need to be considered into the "when".
Start you a list of "considerations" before you ever begin. First and fore most, know your wood's MC to minimize set...........Art
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So Meare Heathe is wrong because is violates the mass principle?
The MH design isn't wrong, but it isn't ideal either. That's why it's not widely used as a bow design. With the right tiller (elliptical) it'll work, but heavy tips are not ideal.
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When it come to choosing the right limb design, all the books I've read leaves out the "when". They talk about back profiles dictating the braced profiles, but more or less skip "when" these particular limb designs are appropriate. I think first, you have to consider side profile before deciding on limb designs of either pyramid, parallel or somewhere in between. The right design for draw length, bow weight, handle design, arrow weight, reflex/deflex , and back deformities (or not) need to be considered into the "when".
Start you a list of "considerations" before you ever begin. First and fore most, know your wood's MC to minimize set...........Art
I think this is where the mass principle comes in. Let the bow's design be dictated by the material.
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Looks pretty good to me dude! Nice work. That young man is going to love it!
You like pretty serious in those shots....glad we're not enemies. :laugh:
...we're not right?
Oh, good grief... Well, it was cold and I was pacing to try to keep warm, and as my wife was taking the pictures, she said "hold still!" And I guess a grumpy face ermerged. That's why I look so serious I guess. Nah, the only enemy I have is Annie May, my Sea anemone enemy...
Awesome. You know i'm joking! I think your pics are great.
I bet you could actually hit the Sea anemone from 30 yrds. You're shoot'n looks pretty good.
But let's get one thing straight. When all the world goes south as long as you're on my side I'll feel better about it. :laugh:
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Hi Stanley ;D,
Hey, your bow looks nice. I'm surprised it came in at 35# at those dimensions you posted. Either the luck of the draw with that red oak or MC was a little high. Next one you make, get it floor tillered and store horizonally in conditions that'll produce 8% MC. Then see if that won't help with set.........Art
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Hi Stanley ;D,
Hey, your bow looks nice. I'm surprised it came in at 35# at those dimensions you posted. Either the luck of the draw with that red oak or MC was a little high. Next one you make, get it floor tillered and store horizonally in conditions that'll produce 8% MC. Then see if that won't help with set.........Art
That's GOT to be it... I need to get a moisture meter. I'm doing everything else right, so that's the only thing I can figure is wrong with the bow that's causing set.
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No moisture meter required. Buy you a cheap humidity/temp gauge and use this chart.
http://www.woodworkerssource.com/moisture.php
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No moisture meter required. Buy you a cheap humidity/temp gauge and use this chart.
http://www.woodworkerssource.com/moisture.php
OK, that was awesome! Thanks!
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And proper moisture content for building a bow is what? 8-10%?
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8% for most woods. Hickory a little drier, like 6%..........Art
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Its a very nice bow, hlstanley. I got carried away with your tiller question.
I struggled with set in the first several bows that I made, unless they were osage. I thought I was tillering wrong, or pulling the bow too hard too early, etc.
I stored my bow wood, and bows, in my basement. Finally I bought that temp/humidity gauge and found my basement sits right at 72%, on a dry day.
I built a bow case, like a big gun case, with sealed doors and two big spot lights in the bottom. I was going to leave those lights on all the time to "burn" up the humidity in there. Didn't do a thing. So I bought a $12 little heater and put in there. Now on a dry day the humidity in the box easily drops to 40%. All my bows picked up weight.
I now store not only bows in there but soon-to-be worked staves and bows in progress. The set problem has largely gone away unless I screws up.
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Its a very nice bow, hlstanley. I got carried away with your tiller question.
I struggled with set in the first several bows that I made, unless they were osage. I thought I was tillering wrong, or pulling the bow too hard too early, etc.
I stored my bow wood, and bows, in my basement. Finally I bought that temp/humidity gauge and found my basement sits right at 72%, on a dry day.
I built a bow case, like a big gun case, with sealed doors and two big spot lights in the bottom. I was going to leave those lights on all the time to "burn" up the humidity in there. Didn't do a thing. So I bought a $12 little heater and put in there. Now on a dry day the humidity in the box easily drops to 40%. All my bows picked up weight.
I now store not only bows in there but soon-to-be worked staves and bows in progress. The set problem has largely gone away unless I screws up.
OK, I'm stoked now... I've been storing my wood in my shop outside where I'm not sure what the humidity is, but I can see my breath in there, so that CAN'T be good... I just bought a moisture meter so I can double check every piece of wood before I build a bow out of it - this is cool, and all this time I thought I was doing something wrong in tillering. I suppose I should have suspected something when every one of my red oak bows takes exactly the same set. Well, duh, all of the wood is stored in exactly the same place!
OK, I can't wait to try this out! I'm stuck here at work until 4:30, but so far I've measured the moisture content of my notebook, the block wall, the concrete floor, one of my coworkers... :o
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I don't have a moisture meter. I don't think they work--the ones you stick into the wood. I have a thing you hang on the wall that tells temp and moisture.
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I don't have a moisture meter. I don't think they work--the ones you stick into the wood. I have a thing you hang on the wall that tells temp and moisture.
But how long does the wood need to set in that environment before it reaches Equilibrium Moisture Content?
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Not sure. Depends on how thick the wood is and how dry you want it. Green wood will lose alot of weight even in the 72% basement, and needs to before going into the box. So I rough out a couple of those somewhat dry staves and put them in the box for at least a couple of weeks while I'm working some other bow. When I finally get one of those to floor tiller I stop and put it back in the box for at least 24 hours. When I actually start tillering I can "feel" how dry the wood is when I'm working it--by the dryness of the chips and the springiness of the wood. It might not be a perfect system but its alot better than what I was doing.
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Outstanding, many thanks sir!
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I made a little oven for curing epoxy part for my model boats. I use a 200w light bulb in series with an old hot water tank thermostat. There are two thermostats in most tanks and they rarely break. The temperature on the thermostat won't match what's in the box very well but once you get it adjusted it will keep it within about 5 degrees. I put an old computer fan in there to keep the air moving. To determine if the wood has stabilized I weigh it every couple of days. I use a digital kitchen scale that I got on sale for $10. It's accurate to within a gram. In my garage a new stave will lose 10-15 grams a day. When you find the weight is going up and down for a week then it's stabilized. Hope this is of use.
Don
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Looks pretty good! I wish i could be of some help on the moisture problem, but its not much of a concern where I'm at. So I don't have too much experience with how to combat high MC. Josh