Primitive Archer
Main Discussion Area => Bows => Topic started by: Roy on April 16, 2013, 06:44:25 am
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How do you guys lay out your self bows or BBO bows, with equal limb length or with the bottom limb a little shorter. And if shorter by how much?
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Equal limb lengths make for easier tillering. I usually make both limbs the same length, but I don't worry if one limb ends up ½" shorter. With nice and even fades, it's difficult to accurately measure where the limbs start anyway. Sometimes I lay out one limb to be one inch shorter, but that only happens when I have a defect in the wood that requires uneven limb lengths.
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Do you pull the bow on the tree from the center of the handle or more to the right where your drawing hand will be on the bow string?
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I always put a bow on the tree so it's supported where my hand will support it, and I pull on the string from where my fingers will be.
The bow is supported on a curved rubber faced block so it is free to pivot and rock like it would in your hand.
It can look weird as it is quite tilted towards the top limb at low draw weights.
IMO doing anything else, or clamping the bow to the tree can give a false impression.
Del
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I pull right from the center of handle on tree tillering.Limb length even or close to it with slight positive tiller.Done it both ways [limbs different length and pulling at the knock point on tree]and don't see any diff.I go by feel shooting and if it feels right it's right to me.Bows stay in tiller.
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I pull from where my middle finger will be on the bow string when an arrow is nocked on the string. I have tried pulling from the center and more to the right and it does seem to make a huge difference in how the limbs bend down on the tree when pulling more to the right. I've been round and round with this with a buddy that makes awesome bows, and I believe what he says about pulling from where your drawing hand is going to be on the bow string is the proper way to tiller a bow.
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Given that I am still a novice at this, having made about 2 dozen bows, so far, I have elected to use the kiss approach to this point. (keep it simple, stupid) I keep the bow limbs even and center the bow on the tree. This makes it easier for me to take photos and flip the image of one limb for comparison to the other. I have also been focusing primarily on circular bends. As I get more experience, I will move into the more intricate tillering methods. What yall said about bow and string positioning makes sense, though, and I am sure I will be gravitating to that method to improve my tillers in the future.
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I watched a fellow lay out a bow and his method made sense to me. He stretched his arms out as wide as they would go and lifted the stave to his nose and said "Yep, there's the middle." He drew a line on the belly at that point where his sweaty nose had left a little round spot. He grabbed the middle of the stave and made a special point of putting his middle finger right on top of that line he had drawn. He marked either side of the hand holding the stave and said "Yep, there's the handle." Then he measured off equal limb length from the ends of the handle. His bows look great. It made me think that there is more than one right way to do this stuff.
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<snip>It made me think that there is more than one right way to do this stuff.
Now that's just CRAZY TALK! How can there possibly be more than one way to do it right??? I mean look at the exact uniformity of all bows ever found in all archeological sites! Surely if all those ancient guys all did it exactly the same way, ...then we should too! ::) :o ;)
OneBow
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LOL, I'll have to try that method:)
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I watched him do it and thought about how long I spend laying one out with a tape measure and combination square and couldn't help but laugh. My next bow I did it the same way, right down to "the sweaty nose move" and found that it worked pretty good. Sweat on the nose is easy to come by in mid-April Alabama workshops when debarking winter cut hickory! ;)
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Most of my bows have symmetrical limbs with the center of the bow placed on the center of my tillering tree. I don't put it on the tree until I floor tiller it and the bow balances on the center point. If the handle area has a riser, I align the center of the riser on the center of the bow. I then tiller the bow with both limbs bending the same.
The only times I don't do it this way is when I'm building a historical reproduction that doesn't follow the above pattern. :)
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Roy, that's the kind of question you can only answer yourself after you've built several bows. Historically, bows have been built every way imaginable. And to be honest, I asked a similar question not long ago. I had been building bows center line plus an inch to 1 1/2 above for the arrow past. That made the upper limb longer. But, that made the lower limb bend more and played with my eyes tillering them. Recently, I built a hickory bow the with the same design, BUT I extended the arrow past so that both working limb were the same length. I made that bow for a newby and make a cut in arrow rest. It shot very well.
I was recently gifted a bow by Blackhawk that was true center of the handle., stift handle bow. I love it. I shoot it better than any bow I've made so far: perface I suck at accuracy, anyhow.
Short answer: Make several styles and see what you like best.
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I have been reading and wondering about limb length myself. I haven't started my first bow yet, so I may be overthinking it. For example, if you layout the bow with 1 inch above and 3 below center, this ends up leaving the lower limb shorter (I think). But then if you add extra length to the lower limb, won't this change your center point?
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This is an interesting topic, especially for someone just beginning. There are several factors that go into play when you start trying to figure out limb length/handle placement. Its also a good idea to use a pencil and paper, and have a bottle of aspirin nearby. If you are going to build a bow with a long riser and cut-in arrow shelf then using the method of 1 1/2" above and 2 1/2" below center is theoretically accurate, and will yield a longer top limb, which crates the need for a stronger shorter limb. All this is good advice for a longer bow or an ELB. However, for the sake of ease and simplicity and choosing to 'shoot off the knuckle'--which it seems many of us eventually gravitate to, then doing as Del and DarkSoul have said: center the bow on the tillering tree at the spot where your hand will grip the bow, this will pretty much ensure that the finished bow will be bending evenly out of your hand at full draw. But as Roy said, the arrow rest will still be an inch or so off-center (this factor is slightly adjusted when/if the string is pulled using a 3 finger draw, with 2 fingers under the arrow and 1 on top. This is also the reason why its a good idea to pull the bow an inch further on the tillering tree than what is to be the shooting draw length; since on the tillering tree the string is only going around a nail or peg, whereas in hand more string is being used to go around a couple inches of gloved fingers.) Sorry for the windy comment, but this may help to explain why a perfectly tillered bow on the 'tree' isn't perfectly tillered in the hand.
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I set my bows up symetrically with the center of the 4" handle the center of the bow. Generally the arrow pass is about 1" or slightly more above center. My bow is centered on the tiller tree and I pull from the center of the tiller string but I leave the lower limb slightly stiffer than the top.
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Pat with all due respect here, if the center of the bow is the center of the 4" handle. And the arrow pass is about 1 inch above center, then that means the remaining 3 inches of your handle is below the center of the bow. Now if you pull from the center of the of the handle, which is the center of the bow, and you make the lower limb stiffer. Yes you induce a positive tiller. However when you shoot that bow, your nocking point on the string will be say 3/8th above the arrow rest. So that means the middle finger of your drawing hand will be will be about equal to the arrow shelf, which is 1 inch above the center of the bow. I guarantee you if you pull from the center of the handle, then slide your pull rope over to the right an inch and pull again to replicate your draw hand placement, your going to have a way more positive tiller. Just thinking out loud here:)
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Sounds like some simply dont like asymmetrical layouts because of the difficultly in reading tiller on the tree. Here is a method described by Glenn St. Charles that whips the problem. layout the bow with same length limbs. On the tillering tree, the bow is supported in its center ( the center of the handle), and pulled from the center of the string. Bow is tillered for perfectly even, symmetrical bend, then once you have it tillered out to full draw....unstring the bow, and cut an 1 1/2" - 1 3/4" off of the lower limb and there you go, a nice positive tiller on an asymmetrical bow. 8) I still need to try this approach.
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I've been doing my self bows exactly like Pat B like I said earlier.My grip pressure is on the center of the handle while my arrow is leaving an inch to an inch and a half above that with my middle finger doing most of the drawing and my index finger along for the ride.Tiller photos drawn by hand show it's in tiller.That's trillering on the tree from the center of the bow too.
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My method is to get it to short brace and never pull it past 18" on the tree max! Watching all the time to see where the set is happening and try to counteract it.after that it's all about the brace,scraping and exercising between sessions. Lastly I get my photographer to take pic in order to make final ajustments.asemetrical bows r all I have built to date. Again I don't know much except what has worked so far.
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All I am saying here is, it does make a big difference where you place your tillering tree pull rope. You should place it as close as possible on the bow string to where your middle finger is going to be when shooting the bow, regardless of your bow hand pressure point. Why would you place the tree pull rope on the bow string, an inch or more below where your going to pull it when you shoot it? Try it sometime, pull from the center of the handle and mark on the wall where the limb tips come down to. Then move the pull rope to the right an inch or so to where your arrow shelf is + figure in a 3/8th higher nocking point on the string. And 3/8th is an average above the shelf for a nocking point. I have read where some guys nocking points are even higher on the string, could that be due to the fact the tiller is way off? If you move the pull rope more to the right, you will apply even more stress to the top limb and it will bend even more, and the bottom limb will bend less. That equals even more positive tiller.
LOL, just thinking out loud here. I guess there are more ways than one to tiller a bow:) The picture below is a buddy's tree and tiller process. The vertical line on the right replicates the middle finger of his drawing hand. He wants the pull rope to come straight down that vertical line, and he tillers the limbs to do that. That means the limb timing is perfect. And when he shoots an arrow, the limbs return to brace equally. Look at the picture and see how the pull rope is pretty much where he will draw the bow back when shooting it. Then imagine if you were pulling from the center of the handle on the tree and the difference it would make with the bend/tiller of the limbs.
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Using "that" tillering tree method with my split-finger/medium grip I'd pull your bow's tiller out in 6 shots Roy. My son would ruin your bow's tiller in one shot. Just goes to show that everyone has different needs.
Personally, I don't use a tillering tree to tiller out a bow. I apply a taper to my limbs and let that doing my tillering. I do use a tillering tree to make sure the limbs are bending as was planned. Or for bows with a longer draw than mine. Other than that, all limb exercising is done by hand drawing. Soz you know! ;) Art B
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That picture there is mine by the way ;) Thanks for getting me involved, Roy... ya goofball.
I try to stay out of these things because sometimes discussions on various tillering methods are akin to discussions about religious beliefs... we all do and believe differently according to what we're taught and deduce from our own experiences, and in the end, little if anything is solved or changed for anyone ::)
I try to remain receptive to ideas, theories, or practical applications that work well for others though, so if yinz are too, maybe we can have a worthwhile discussion here.
The bow above is assymetrical, and is being tillered for a split finger grip on the string and a grip on the handle that applies even pressure across the width of the hand.
Art, yes, we do have varying needs when it comes to tillering... as many different needs as there are shooting variations. The picture above is set-up to replicate MY shooting of a bow designed to my specifications/preferences only. I'd never proclaim it suitable for everyone, or for every bow. That's why I try to make my tillering set-up as versatile as possible.... because I don't always build them the same.
If that exact set-up didn't suit your shooting particulars, or bow design, you could simply move the hook on the string, the pulley down near the floor one way or the other, or change the cradle's shape to replicate your holds... as I've done numerous times depending on the needs of the archer I'm making the bow for. It's actually quite quick and versatile. And if utilized properly, the bow's tiller won't change once it's done. The limbs are tillered in sync with respect to the archer's holds from the first light tugs on the string, until completion... so there's no cause for it to do so... unless there was something inherently wrong with the wood itself that caused change following shooting-in, or it was shot differently than it was tillered for.
I'm wondering how you could pull it out of tiller if it was tillered to how you pull it? Or are you simply saying that the above set-up wouldn't work because it doesn't replicate how YOU draw or design a bow? ...which I completely understand.
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That's the same method I started with DWS. Worked fine for me until I started giving some bows to family and friends. Then the bow's tiller health became an issue because of non-compliance with handling/shooting instruction. So I started pulling my bows from dead center and setting amount of positive tiller needed for each individual shooter.
All I can say is God bless the uninitiated when it comes to these self bows :'(!
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Oh so I'm a goofball DWS? LOL, well maybe at times:) Did I tell ya your bow's tiller sucks?:) LMAO
We all know by now that none of us will build bows exactly the same. We need to know our style of grip and split or three under requirements before even designing a bow or putting it on the tree. What works for one bowyer might not work for another. One rule I have for wooden bows, is to not let others draw my bow, unless they shoot like I do and have the same draw length as I do. With that said, I still advocate pulling the bow on the tree from where you will pull it when shooting it. I don't care what you set for a positive tiller, if you pull from the center of the handle on the tree, then pull and inch or so higher when shooting, the limbs are going to react differently.
Anyway Art, it's really good to see you posting again, and I hope you are doing well my friend. Did I send you pictures of my first tri lam build? Made this bow for my wife. Osage belly, ERC tapered core lam and boo backed. Gonna make me some more of those.
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Yeah, I think I got that one pic Roy. Nice bow!
Like I said before, I don't use a tree to build/exercise my bows. Only to see how they're bending. Bow scale is mounted from ceiling so I don't need a tree for that either. So, IMHO, the less you use a tillering tree the better.
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I set my bows up symetrically with the center of the 4" handle the center of the bow. Generally the arrow pass is about 1" or slightly more above center. My bow is centered on the tiller tree and I pull from the center of the tiller string but I leave the lower limb slightly stiffer than the top.
Ditto for me. Couldn't have said it better.
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"I set my bows up symetrically with the center of the 4" handle the center of the bow. Generally the arrow pass is about 1" or slightly more above center. My bow is centered on the tiller tree and I pull from the center of the tiller string but I leave the lower limb slightly stiffer than the top."
I have a couple questions for those that do it this way... if the center of the bow is the center of the handle and the handle is 4" wide, wouldn't it be impossible to have the arrow shelf/pass any closer than 2" above bow center?
Also, how do you KNOW the lower limb is slightly stronger than the top? By measuring from somewhere on the limb to the string? By judging by eye? The reason I don't rely on these as accurate gauges of relative limb strength is... the slightest difference between the limbs, some of which may not be outwardly visible, means that while we may leave the bottom limb 'appear' stronger, or 'measure' stonger, it might not actually BE stronger, i.e. ACT stronger. ...Hey, there's a chance "leaving the bottom a little stronger" may get you in the ballpark... if both limbs are identical in their inherent strengths, shape, side profile, and while unbraced, both tips start equadistant in relation to the handle, etc... but unfortunately such things aren't always the case.
So that begs my next question... What if there's some type of difference between the limbs themselves, such as, one limb has reflex and the other is straight or has deflex? How do you measure, or eyeball, such a bow throughout the process of tillering so that you KNOW you'll be maintaining limb harmony during the draw and return to brace with specific holds on bow and string? How will the limb's strengths, relative to one another, reveal themselves to you? To what degree of accuracy? And when?
Another question that comes to mind is... Why. Why pull the string from the center of the handle on a symmetrical bow, or ANY bow for that matter, when it's impossible to shoot it that way? Why not simply pull it from where you'll shoot it, when doing so directly reveals, addresses and/or eliminates many of the possible hurdles en-route to an expertly tillered bow? ...of ANY shape or design, or with inherent/internal limb differences. Help me understand. Is it because it's easier to judge the arcs in the limbs?
Some folks are bending and training the limbs, closely critiquing them, and doing their very best to 'tiller' them, while pulling them from a spot on the string 2" from where it will be shot... ever. That, along with the fact that the farther "a little stiffer" is from true limb syncronization, the more erratic the arrow's flight, the more handshock, and the more the resulting wood 'confusion' can help cause tiller shifts during the bow's early life, and who knows what else... because they simply weren't trained to be used that way. So then what? Flip the bow and see if it's any better? hope THEN that the tiller holds? Make adjustments to regain some arbitrary measurement that may have not been the best thing for the bow to begin with? miss target draw weight due to corrections, further confusion of the wood, and perhaps cause unnecessary set in the process?
If I had to do it THAT way, I probably wouldn't want to use the tillering tree either :)
The way I'm currently going about it... which I'm not saying is perfect, or the way everyone should do it... has and will continue to evolve as I gain understanding. But as it stands now, when the bow's limbs are out of sync in relation to how the bow will be drawn and shot, I know it on my maiden voyage to the tillering tree, immediately, with the slightest tug on the long string. I'll take it back to the bench and begin harmonizing the limbs right then.... removing wood from any stiff areas I may have noticed... if none were yet visible with so little bend in the limbs... I'll remove wood along the stronger limb's entire length. Once they're in-sync, I'll continue on, doing my thing tillering, bending, training, inching my way down the tree, while keeping an eye on their harmony and making the adjustments needed to maintain it.
If, for instance, I do a little work on a stiff area on one limb, and the hook invariably strays from the line as a result, it often takes VERY little wood removal from the opposing limb to bring them right back in sync. So very little in fact, that it shows me just how delicate and precise an operation this can be, and with that, I don't think there's any way I could get it this close by setting and keeping brace height to a predetermined measurement, by measureing limb travel, or by guessing, which in reality is what "leaving the bottom limb a little strong" is, let alone as-accurately critique and gauge corrections by the 'feel' of the bow's balance during the draw.
Ultimately, the proof is in the puddin'... When I'm done, after reaching full draw with timed, tillered, and excercised limbs on the tree... I have YET to have a bow feel anything but perfectly balanced in my hand upon the first draw. From the first amount of pressure I put on the string as I begin the draw... all the way to anchor... it pulls the handle unequivocally straight into my hand without the slightest hint of tipping either way, and the arrows fly great from the nock point I determined before the bow was begun. I guess such consistant, positive results within a range of bow designs and shapes are what has instilled my trust and confidence in the tillering tree the way I use it... and why I don't have a need to try to 'feel my way' during tillering.
There's a lot going on while tillering, and more than one way to skin a cat most times, but I'm trying to simplify it while remaining versatile by seeking and utilizing the most straight-forward tillering method to achieve syncronized limbs, predictably perfect arrow flight, and the most balanced, smooth shooting bow I'm capable of... with no backtracking to fix tiller shifts, without missing target weight, and without trying to adjust for untimely limbs and the resulting poor arrow flight by moving the nock point around... regardless of whether it's symmetrical or not, regardless of limb differences, and with a variety of grip and string holds.
Sorry... didn't mean to write a book there ???
I should probably be shocked if anyone decided to try to follow me through THAT mess :o
I'm goin to the shop to clear my head.... find my 'center', if you will :)
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Geeze Jeff, took me an hour to read that. But I totally agree wif ya son.
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Had to take a coffee break after reading all that Jeff ;D!
Gotta a question for you though? I've no doubt that you build a fine bow and it holds up quite well for yourself. But how do you tiller a bow for someone with your tillering set-up who requires a good bit of positive tiller because of a heavy low wrist grip?
Like I stated before, I've used the same rig both you and Roy like. But with that set-up the upper limb is engaged and the lower limb just kinda follows. IMO, not the kind of set-up needed for someone who engages both the top and lower limb using a split-finger draw. Drawing the string from the center addresses even strain to both limbs but doesn't address the strain the lower limb feels just outside the fade from the split-finger draw. So I can't see a perfect solution for tillering out a bow when a split-finger draw is involved. Three-under draw.........a different story.
Again, I don't tiller out a bow on the board/tree. Comstock wrote, "good tapering produces good tillering". So my limbs are tillered before they ever see any kind of string. From day one, I've subscribe to the notion that," a bow is built as it stands in the tree". I've never flipped a bow in my life looking for better tiller. Most of my bows have off-set handles w/shelves cut in.
If you strive for even limb strain (drawing the bow by hand and not with a rope) at full draw, you can tiller out any limb configuration by applying the proper profile to each limb. Even limb strain, per type of draw, will, and I repeat, will produce the correct amount of tiller needed for long term tiller health.
This is basically how I approach my bow building. Others approach things differently. No one can say one way is better than the other if it's working for us.
Need more coffee now ;D!
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Bout time you get yer butt out of bed ole boy:) Afternoon Art..
It scares me to death just thinking about drawing a bow back by hand a few times to reach your draw length like you have told me you do. I'm sure with a pre tapered limb thickness and width, the bow does/will have a good natural tiller bend. And that's how your and my bows are built from the start. But what about any differences that might lie inside the two different limbs, as in bottom of tree to top of tree stave? I will say I've been laying out my bows like you explained it to me a few years ago and I'm pleased with the bows I'm turning out. But I work the crap out of them on the tree, and you don't? However, I shoot three under and that in it's self makes tillering a bow a lot simpler due to the fact you are pulling closer to the center of the bow and attaining almost equal limb strain. I have played around changing the pull rope position on my tree from split finger to three under to check the difference it makes on limb movement, and three under sure evens it up a lot more than split finger. I know Jeff makes his bottom limb about 1.5 inches shorter than the top limb, I don't. So his tree theory/setup works better for his bow design. I may go that shorter bottom limb theory in the future though, maybe not. Maybe some day when I get up the courage, I'll just string one up to a 6 inch brace height from the start and start pulling her back by hand. I'm retiring the end of this month, guess I'll have to make a road trip down there to WV and make some bows with ya ole timer.
I think threads like this are good medicine, it's a civil discussion about how we all go about building bows. Hopefully we all can learn from one another.
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I'm learning a lot, keep it going!
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Since you're retiring soon Ol' Man, maybe you can now pay closer attention ;D!
Hey, you start with reasonably (quality) bow wood, apply a nice taper, so what could go wrong? Limb can't hinge, and you can tug on the limbs until they break. But that'll take a bit of tugging.
Now for different working properties/strengths, why I reckon carrying the same amount of mass in each limb will help there. Try this Roy: mark the center of your bow. As you're tillering, make sure your bow balances on your center mark. That'll keep your limb mass equal. Then you'll start to understand why the old timers preferred matching sister billets for their bows.
Say you "build a bow as it stands in the tree", and maintain equal limb mass as your building it. Here's what you're gone to see. Top limb a bit thicker and wider than the bottom, or bottom limb a bit narrower and thinner than the top. Do the same thing with matching sister billets and you have a more aesthetic pleasing bow. Easier to work with matching limb properties, at least for me.
If this make any sense to you Roy, I don't believe a bow should be pulled the first time until everything possible is done to insure minimal damage to the wood's fibers. Only way I can see to do that is to pre-taper the limbs instead of tapering/pulling as you go.
Something else I was going to mention. But heck, you know how that works at our age :'(!
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Something else I was going to mention. But heck, you know how that works at our age :'(!
So your telling me ya forgot what ya was gonna say????
LOL I understand EXACTLY about forgetten chit:)
So by limb mass, your referring to weight I take it? So for that to work would require equal length limbs. Well not really I guess, more like you explained above.
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Limb length design, that's what I was trying to remember Roy :laugh:!
Funny, but I never think of limbs as being different lengths. I think in terms of off-set handle, or amount of off-set for the different type grips (straight/high, medium to low wrist). And that's really what's involved with different length limbs. But you'll still see plenty of folks using a low wrist grip with an off-set handle or a straight wrist with a centered handle. You'll end up pull your hair out trying to explain this stuff only to have someone who's made one or two bows come along and say none of this stuff matters, and just shoot from the center of the bow ::).........Art B
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I too spend a great deal of time establishing an accurate taper in both width and thickness prior to ever bending the bow by any means or by any amount whatsoever. Doesn’t matter if it’s bamboo backed osage bow, an ELB, or the most character laden osage selfbow (they’re actually the most fun for me, and the tapering is a BIG part of success with them). I often wondered if I was spending TOO much time doing it, because I’d see other guys just grab a big ol’ Farrier’s rasp and rip ‘n tear. But I think it pays off to spend as much time as it takes to get it as good as possible before any ‘action’ takes place.
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Art, you asked about tillering bows for other grips, hi, low, etc. I have a handful of these inserts that drop down securely into my tillering tree cradle. I've got a couple more around here somewhere, but couldn't locate them just now... shop's a little 'disturbed' :)
Anyhow, even though I built my cradle to accomodate the shape of handle I prefer, I'll drop the flat one or convex one in there on occasion, after the bow has at least made it to brace so it'll sit there, to make it easier for the bow to pivot if it so wishes, and let me know even better if I've got the thing timed/balanced. It's kinda like fine-tuning the thing, cuz if one limb is just a little stronger than the other, it's gonna be easy to see.
For balancing the limbs for someone who shoots high or low pressure on the grip, which one I'd use would depend on their handle shape and where they put the most pressure. Even if I had to make a new one to accomodate them, it only takes a couple minutes. Since they just drop in, they can be switched in split second if I want to find a better-suited one, or compare or check something or whatever. The insert that is high on one side can be flipped around for high or low pressure on the handle, and used on some locator grips.
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Here are the pulleys down below. Which one is used depends on split-finger or 3 under, and whether the top limb is on the left or right. They're each secured by a single set screw, so they can be loosened and moved anywere they're needed.
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Nice set-up you have there Jeff. Yep, that's about all the different heads one would need.
No, I don't think you can spend too much time up front with these selfbows. For example, I've applied my taper, kepting an eye on equal limb mass as I go, and have had a number of bows come out perfectly tillered when first strung. Many others only needing a few scraps to even up the tiller. Then limb weight reduction from there as needed. Dang near impossible to miss weight when the bow is constantly in the hand and not on the tree.
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Very cool, Jeff.