I'm a new bowyer so i'm no expert at all on this issue, but i've seen in come up in past posts with a lot of "this is what you do" but no "i tried that, and it screwed up my bow" or any evidential remarks. Most guys on here advocate positive tiller (lower limb stiffer than upper). Has anyone tried it the other way around? I would normally go with what the experienced guys say, but it's not making sense with my physics teacher brain and what i've read elsewhere. I know Dean Torges is highly respected in bowyer circles, and he has some interesting things to say about this issue here:
http://www.bowyersedge.com/organic.html
I would like to know what y'all think about what he says here, but ESPECIALLY about any experiences tillering this way. And if i'm simply misunderstanding Dean, then please by all means tell me that too! :knothead:
****See post below for my proposed solution and experimental results :)
I think your reading it correctly from Dean.
But the big thing is Dean himself told me he always makes his bows with longer top limb up to over 2" he says. That could be the difference.
My goal is at full draw, for the bow to be balanced in my hands as Dean says.
Everytime I use a tiller tree to get limbs bending perfectly the same, take off the tiller tree and pull back (with my 3 under draw), it always shows that bottom limb bending much more than top.
Only way to overcome is to make the top weaker. I keep this up until the bow is balanced my hand with my draw, and it always ends up with top limb bending more undrawn.
Dean is advocating dynamic balanced tiller - not negative tiller. Same length limb bows are problematic as he states and sometimes a negative tiller is required to achieve balance on these bows, especially with three under shooters. He has always advocated a shorter lower limb for dynamic balance reasons.
You know, I have read thru that article twice and its about confusing. I am not sure what dean is advocating.
QuoteOriginally posted by bigcountry:
I think your reading it correctly from Dean.
But the big thing is Dean himself told me he always makes his bows with longer top limb up to over 2" he says. That could be the difference.
My goal is at full draw, for the bow to be balanced in my hands as Dean says.
Everytime I use a tiller tree to get limbs bending perfectly the same, take off the tiller tree and pull back (with my 3 under draw), it always shows that bottom limb bending much more than top.
Only way to overcome is to make the top weaker. I keep this up until the bow is balanced my hand with my draw, and it always ends up with top limb bending more undrawn.
That's why I've always thought it funny when folks say they can't tell the difference in tiller between 3 under and split.. To me it is readily noticeable on the first draw of the bow..
So does it really just come down to fine tuning the tiller based on how it feels in the hand? Applying this to my latest bow: arrow rest is 1.75" above geo centr, planning a pistolish grip so hand pressure is concentrated about .75" above geo center, do i need a stiffer upper limb or not? It makes sense that i should, either way i just finished putting tips on the nocks, so i'm gonna see how it feels, put a bump on my tiller block to represent hand pressure and draw it out. But what am i looking for? should tips line up evenly if i'm correctly approximating actual draw? I guess i'm more experienced at bowyering than archery, so i'm not exactly sure how it should "feel" :knothead: :knothead: :knothead: :knothead:
I tiller both exactly the same at the same lengths and use my nock point and arrow pass as my adjusting points for tuning and balance. Sure is easy.
Give that same bow to someone else that grips different than you Pearly and "easy" goes out the window.
If you shoot a layout like Dean, and grip a bow like Dean, then Deans explaination is right for you.
If you read Dean's article real close, you'll notice that he's baffled to why and how same length limbs can functions properly according to his own logic. Well it can't, because he mistakeningly assumes that dynamic fulcrum is two inches above center, when in reality (say, using split fingers), dynamic fulcrum is centered or below.
That's why with Vanillabear's bow, the lower limb petered out on him.
I really like Vanillabear's approach though. Experiment for yourself, if it doesn't work, move on and find what does.
Too much taking someone's word for things these days. We seem to want things "easy" :D .........Art
Thanks guys. What you're saying makes sense as well, which means i may just be more confused!! Anyhow, my bow is now with a handle layout which puts hand pressure .75" above ctr and arrow pass 1.75 inches above ctr. I shot her some yesterday and today the negative tiller was a little more than it was yesterday. Don't know what that means i should do? I just shot some more down at cabelas (fun place!). She shoots fine, doesn't feel off in any way. Do i leave her? Am i on a path to destruction?
Back to my other question: If i put her on the tree with a raised shoulder and the fulcrum concentrated where hand pressure should be, and pull exactly as i would with arrow nocked, should it balance, and should the tips line up or should they not line up? I'm fine with experimenting (hence my 3rd and 4th bows nuking on me!), just want to know what to look for on this one.
IMHO the lower limb should be stronger than the top one. Static tiller is only one side of the coin. Much more important is the dynamic behavior. How does it shoot ? Is the limb mass well balanced ? If the limbs are not well synchronized and the limb mass is not equal then the bow will have some handshock and a lot of the stored energy will not be transfered on to the arrow.
With a slight positive tiller ( approx 1/4 for split grip ) I get the best results and the bow ( d/r-design ) shoots without any handshock, even with very light arrows.
----------
Andy
Well, as i said, she's shooting quite well. The arras zip in and get good penetration. Was gonna try cabelas chrono just to see, but it wouldn't pick up for some reason (can't be that slow :knothead: lol. Anyhow, thanks guys for your input, and i'd still love to hear more/others. It's good to hear some of what you've tried and works/doesn't work! Good things to think about, even better if you can understand!
BTW, i don't know about you guys, but when i draw with split finger at nock point on the tree, the bow rocks toward the top limb, UNLESS i place a fulcrum just under the arrow pass(about 1.25" above center). Now if you strangle the bow in this dynamic, i can see it will put a great deal more strain on the upper limb, yes? since you are still drawing the string from just above that point. Where as if you hold with pressure concentrated at the v of your thumb/forefinger, that will reduce the strain on the upper limb for this type (which means in any case it's gonna bear the greater load, so it should be stiffer?). Gotta love it, tell me if my thinking is screwy:)
I tiller on a fulcrum and try to replicate hand pressure and all that stuff. I get her close and start shooting her and final tiller with a mirror and in my hand. I do usually make my bottom limb shorter like Dean and go for a little stiffer than the upper limb.
They shoot good, feel good and do what a bow is supposed to do so I leave it that. No since in overthinking it IMO. If I go getting into dynamics (whatever that means) I'll really be in a mess. LOL
Stiks
I shoot 2 under and I can actually "Feel" if the top limb is weaker or stronger.
For my 2 under style of shooting, a slightly positive bottom tiller works out the best for me.
But here's the thing, you can achieve an effective positive bottom limb tiller in several different ways. First was is by where you place your hand on the bow, and another way is the length of your limbs. Top limb a little longer than the bottom will achieve that positive tiller on the bottom.
Just gotta play around with it and what feels right, and shoots the best for you.
I want the web between my thumb and forefinger to be as geometrically center of the bow as possible and my arrow nocked about 3/4"-1" above that center.......basically right above my knuckle, and if the working part of the bottom limb is slightly shorter than the top limb, my bows will shoot like a dream.
That's just what works for me, you will be different from me or anybody else so all we can do it offer advice based on our own experiences.
How it feels in the hand is important. I've made bows with stronger upper limbs, stronger lower limbs, bend in the handle bows, rigid handle bows, narrowed handle bows, wide handled bows, no shelf, shelf and probably some others I can't think of. I can't remember a miss where I could blame it on the bow. Make a the way you think it should be made and that will make you feel better and you'll probably shoot better. :) Jawge
Quit that crazy talk Jawge!
People can say, "just do what feels right", but what one has to remember is new bowmakers do not know what feels right until have went thru many wrongs.
So, newbies, need some guidelines to get started. And ultimately thats what this thread is about. I think older folks forget what its like to be new.
For instance, when I started, I had severe trouble reading tiller. I had to use all kinds of tools, like the "kizmo", digital cameras, photoshop, etc. Now, I think I can spot a flat spot 100X easier now. I remember experienced makers, saying, "just draw it in the mirror and make adjustments". That seemed like an impossible task. I had to train my eye what to look for.
Tiller for a 1/8th to 1/4 positive tiller on top limb , then fine tune to your grip.
As a newbie, I am more lost now then when I first started. Definitely a lot to read and read and read again to understand. I am thinking now I need to get out the video camera and draw all my bows with different finger grips and record how it all feels.
Roy, not sure what you mean exactly as a newbie myself. I know you get good reviews for your tillering! I know I messed up my first boo backed reflex/deflex bow by having a weaker lower limb due to a slight and I mean slight error in one spot I did not see. I adjusted by moving my nock point- I shoot 3 finger split BTW. It shot great for about a year until I started noticing a more weakened lower limb and it cracked a few days later. Like others I want to understand if possible what to do so I repeat my own shortfalls.
Thx for all the great inputs/considerations.
You want it simple, here's simple.
Just tiller for even strain to both limbs at full draw and that in itself will produce the proper amount of even/positive tiller for your bow. With even limb strain, or one limb not receiveing more strain over the other, long term tiller health will be preserved.
Think about this real careful. If you do as prescribed above, there can be "no" negative tiller for the top limb because of the way we grip the bow and string.
For those few who advocate a stronger upper limb for what ever reason, do so by disregarding even limb strain. Here, best timing/balance and speed suffers......Art
Positive tiller is when there is a greater distance from the end of the riser measured to the string on the top limb, than the distance measured the same way on the bottom limb. Just like measuring your brace height, but measured from the ends of the riser to the string.
Tiller the bow on a tillering tree untill you are about 4 inches from your final draw length, then tiller the bow the rest of the way just pulling with your hand like you will shoot it. You want the bow to feel balanced as you pull back the string. If one limb is stronger than the other, the bow will let you know. A mirror is great for the final tillering.
Art ole boy, give these guys the full story on this son.. You got more B.S. than I do:)
In my opinion and after deep thought over many years...OUCH. That hurt. I forgot I gave up on overanalysis. Gives me a brainache.
If you are new, stick with simple. Then refine your thinking as you go. Don't get ahead of yourself. There are few "right" answers.
Alright boys, thanks for participating! I've done a couple more searches and actually turned up some other threads where some of this has been discussed
(example: http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=000112;p=1 ),
so sorry to resurrect the debate! :readit:
Thanks again for putn up with us hard-headed newbies!
Yes. :jumper:
Chuck, how is it you get the prize without weighing in on the question? :D
K-hat, that last post is a pretty good summary of what "tiller" may actually mean! ;)
Stan
Right place/Right time Stan. I do feel just a bit guilty tho. The other guys put more effort into the answers than I did. Now I have a question...
What did I win? :goldtooth:
Bow building is Fun.
Bow Building is Learning.
Enjoy the journey.
And most of all, pass on as much info as you can. None of us know it all.
Roy you couldn't have said it better.
So I'm not the kind of person that can be given a problem and then drop it when I don't find an immediate solution. It bugs me, it eats at me, and no matter how I try not to, my mind continues working on it till I figure it out. So, here is my proposed solution to the negative vs positive tiller quandary, which limb should be stiffer and why, as well as commentary on other bow-making observations. Along the way, I will state some things that we all already know (or at least maybe you do) as if perhaps not known before, not to promote the idea that I discovered it, but rather so that no assumptions are being made about what the reader knows/understands and nothing is taken for granted. So bear with me in that regard.
I've been teaching science/physics for more than 10 years now, so scientific methods and experimenting are pretty deeply ingrained in me by now. However, I didn't want to experiment on perfectly good bow wood and invest a lot of time in making failures, so I opted for something quicker and less destructive. I took a 60" long 1" diameter pvc pipe I had laying around, and put holes in each end to serve as nocks for a pvc bow. It is uniform and elastic enough to make a good approximation of how a bow would behave. I then put spring scales at each end of a makeshift bowstring to be attached to the nocks, so this would register the force acting on each tip of the bow. I then proceeded thru trials of differing hand positions and nock points on the string and observed mainly 2 things: forces registered on the spring scales and the amount of tip deflection from the straightened position.
The first thing I noticed was the most startling, but was also a face-palm. No matter how I pulled and held the bow, the spring scales registered nearly identical forces at each end. My problem before this was that I was looking at the string as being divided in two segments (top and bottom), each attached in two places: at the tip and at the arrow nock point where they join. This was big time WRONG!! This would allow the segments to carry different forces depending on how the bow was operated (which was my previous thinking) , when IN FACT it is more like one string going one load to the other (tip to tip) with a pulley in somewhere between (the arrow nock/fingers). The tension is such a string is going to be uniform all the way through, allowing the force to be equal at both tips. This is HUGE!! With all due respect to Dean Torges, this was the fallacy in his representation of the bow as a seesaw with a fat kid and skinny kid. The bow system is much more complex that this, and simply cannot be represented this way. What's the point?? Here it is: no matter where you grip the bow OR the string, the forces acting on each limb are the SAME! If one limb feels 20#, so does the other. If one feels 30#, so does the other. So, contrary to Dean's thinking with the seesaw (with all due deference and respect), the shorter limb (top on an equal limb bow when measured from hand pressure fulcrum) does not bear a greater load, but the same load as the longer (bottom on equal limb bow).
WAIT A MINUTE!! You may say, "but then why does one limb obviously bend more than the other when forces aren't centered?." Good question, but the answer is NOT in the size of the force acting on them since these are equal. So do they bear equal strain? Depends on how you define strain. If strain is load, yes. As an engineer defines strain, I don't think so (I believe it takes into account length of the deformed object), but going into that is over my head at the moment. Surely we have some engineer bowyers out there who could chime in on that one. But really, that is neither here nor there. Let me answer the question about the amount of bend in each limb a little in layman's terms. When spine is measured for an arrow, length matters. A short arrow will bend LESS under the same load as a longer arrow (provided the distance from anchor point to load is greater on the longer arrow.). THIS is exactly why an equal limb bow tillered on the tree with fulcrum at geographic center will show MORE bend in the bottom limb than the top when gripped and shot conventionally. The lower limb, in effect, IS longer than the upper in this scenario, and being under identical load will have a greater amount of deflection at the tip than the upper for the SAME reason the longer arrow bends more than the shorter one under the same load.
So, why does it matter, since they are under the same load no matter how you design/tiller the bow?? Well, all the experienced bowyers will tell you (as they've told me), "it just don't work buddy!" You're bow may function now, but eventually it's gonna malfunction. The tiller will get all screwy or it'll just flat out blow on ya. Before I go into my proposed explanation for that, let me confirm that in my experimental bow, the longer limb ALWAYS flexed/bent/had more tip travel than the shorter limb. Period. Why? Because they are identical and have the same stiffness, they are subject to the principles above as applied to an arrow shaft. One question that remains (haven't been able to go back and verify) is the ratio of limb length to deflection. Does a twice as long limb deflect twice as much, and show the same amount of deflection at it's midpoint as the shorter limb (since equidistant from center)? I suspect the answer is yes. I know, I digress, and haven't answered the question at to why such a bow will self-destruct if not adjusted in tiller. I believe the answer here is in timing. Let's first assume both limbs have equal mass. If that is the case, then the acceleration of each limb at release is directly proportional to the force acting on each limb. Since we've already verified that is true, then we can infer that the limbs will in fact experience the same acceleration when the arrow is loosed. Anyone see a problem? I do. If one limb is bent further (the bottom in our equal limb length and strength bow), then it has further to move! This creates a timing problem. The top limb is gonna tend to finish before the bottom. I believe this causes the bow to retain more energy (rather than going to the arrow), and that energy remains in the lower limb and eventually destroys it, not to mention creates hand shock. That's an unverified assumption, but I think it fits with our observations.
Fortunately, we already know the solutions to these problems. Make the lower limb stiffer (positive tiller), or make it shorter. All I'm proposing is hopefully an understanding of WHY these adjustments are necessary and why they work. So the seesaw analogy was definitely problematic and leads to some misunderstandings, but Dean was dead on in his solutions to these problems. What happens when we shorten the lower limb? It's gonna flex less AND have less mass, and be more in time with the top limb, (this also fits with our equal force per limb idea!). What happens when we just positive tiller/make bottom limb stiffer? Well, limbs will have about the same mass, but will have close to the same amount of deflection and distance to travel home. Given the same force (again, verified), they will arrive in sync.
Well, there's more to talk about on this (string angle and balance in the hand, split vs. three under, where are the fulcrums really located, etc.), but my brain hurts, and I'm tired, and it'll have to wait. Feel free to comment on those, however!!
BTW: This is all perfectly in line with the advice given on this post and elsewhere, I guess I just had to figure it out fer myself as to why it works this way, and hopefully so I can be more thoughtful in future bow designs!
Happy shaving :D
Boy that was a long post!! You might need one of these :coffee: to get through!
"limb timing results from balanced symmetry at the full draw position, and that is the ultimate goal."
I believe this to be a false statement.... Limb timing is about getting those limbs to stop dead at the end of the power stroke at the same time.... limb symmetry at full draw will not do that in many cases.
Having good limb symmetry is a good optical tool for achieving balanced limbs, but the symmetry itself has nothing to do with the actual timing.
"my bow is now with a handle layout which puts hand pressure .75" above ctr and arrow pass 1.75 inches above ctr."
In this case you are definately going to see a negitive tiller measurement at brace off the fades..... a tiller measurement is just that too. a measurement top and bottom at the fades.... it doen't matter if it's positive or negative as long as the limbs are balanced correctly and stopping at the same time.
The whole tillering vs balancing limbs has to be done from the pivot point, or pressure point you put on the bow.... who cares whether the bow balances in your hand when you are carrying it or not. it's having the limbs balanced in the power stroke that makes a good shooting bow that is dead in the hand.
if you are putting pressure on a point in the grip below true center of the bow, and your shelf cut out is above center in which your fingers are located on the string above true center the strength of the limbs need to be adjusted so when you drop the string both limbs hit the end of the power stroke at the same time.... if you don't do that, the bow is going to rattle your teeth loose and loose a lot of efficiency.
there's about 10 cents worth... IMO
btw... i like your take on this SEMO i do my glass bows the same with same lingth limbs and about 1/8 positive tiller instead of shortening the limbs.... although i gotta admit it's easier to accomplish shifting my tip notches a 1/4" up the hill...
I agree that 'symmetry at full draw' should not be the focus. Timing is more important. What if a selfbow stave has odd, undulating side limb profiles, with net deflex in the bottom limb and reflex in the top, and you use 'symmetry at full draw' as your gauge/goal?... that's not going to work out well. Such a bow's limbs are going to return at different rates, the faster limb dragging the arrow nock with it which builds arrow porpoise into each shot and the untimed limbs are going to cause added hand shock.
Bows tillered with perfect limb timing as a 'gauge' to our progress during construction as well as out ultimate 'goal' result in bows that treat the shooter and arrow best.... even in spite of many possible physical differences between their limbs.
Along another line... "who cares whether the bow balances in your hand when you are carrying it or not."
I absolutely do. It's easy enough to build a bow that does both... limbs that return together in a bow that doesn't incessantly try to fall out of your hand.
"Balancing in your hand while you're carrying it" is important to me because it means the bow is also balanced in your hand while shooting it, which means it points as effortless as a finger, high or low, back and forth, at moving targets, while canted at any, even extreme, angles.
When I build a hunting bow, I try to build a bow with no uneeded mass size or weight, a bow that physically balances in the hand somewhere between the handle and string fulcrum points, and pulls perfectly straight back into the bow hand as its drawn(tillered for the shooter's specific grips on string and bow) AND whose limbs are timed so that they return at the end of their power stroke together... THAT'S the bow that feels magical... the bow that's effortless to carry, quick to point and shoot, that shoots an arrow predictably well right out of the gate without tuning issues, the bow that feels like a natural extension of the shooter from the first time they shoot it and thereafter.
Those are 'some' of my hunting bow requisites :)
nobody has asked what kind of bow hes building , at least that i can recall...
OK, I'm not a bow builder, but I have finished a couple of blanks (Hill blanks) and reworked a bow to reduce draw weight a few pounds. Tiller and timing are pertinent items of discussion for these projects, and I have pretty much just followed the rule of about 3/16" difference between lower and upper limbs at brace. My results have been good, and the bows I have finished have turned out smooth, accurate and with very little shock.
I have shot other bows that do not perform as well, though, so I am a bit curious about the "timing" issue that several people have mentioned. Is there a way of accurately checking the timing of the limbs other than just "feel"? What I am hearing from this post is that merely achieving correct positive tiller does not guarantee that the timing will be correct. Can someone who knows more about this than I do help me understand?
Greg, best timimg is achieved IMO when one grips their bow properly per the arrow pass layout.
Closer the arrow pass/shelf is to the dimensional center of the bow the straight the wrist. Further away the arrow pass the lower the wrist.
Long bows, with their straight back handle design, are commonly gripped using a medium wrist/grip. Arrow pass layout is generally around an 1 1/2" above center requiring a positive tiller somewhere in the neighborhood of what you mentioned. Or at least that's how things work out for me...........Art
wait a minute now art. are you telling me that the way i hold my wrist has something to do with the timing of my bow?
i think this is too much thinking. you could have you a big ol' mess-o-shavings by now , and probably a bow with all that jaw flappin and hamster wheelin.
seriously though , its dark magic. you wont grasp it until you have broken a few bows.
have fun!
:thumbsup:
-hov
It really is just that simple ain't it Hova. Best way to learn.........Art
K-hat, I don't see the limbs of a bow as levers. Rather, I see them as springs. If the limbs were levers, then each of the nocks of a 50# bow would have 25 # of force as the was drawn. This does not appear to be the case. There is very little force applied to the nocks at the draw. But there is a fulcrum involved at the handle. There is a lot going on when a bow is drawn. Practically speaking, I tiller the bottom limb a little stiffer(1/4") as shown at full draw. At least that is the ideal. I really don't like my selfbows to look like glass bows. I leave the character in the bow. The ideal tiller, then, is usually not the picture perfect image. :) Jawge
I start by tillering to measurement, Then I go to work on timing the limbs and working the tiller to keep same. As to the balance , I like a bow that balances perfectly in the hand. Actually on my finger when laid in the deepest part of the grip. When a bow is tillered , timed and balanced it is like the man said a thing of great beauty.With glass you should be able to get geometry, tiller and balance. sometimes with wood there are more variables that have to be dealt with and geometry gives way to limb balance and tiller. However most of the bows i have seen you guys build are things of beauty.
God bless you all, Steve
Listen to Ole Art, cause I taught him everything he knows bout bow building:)
There is no measurement rule that will time your limbs be it positive or negative tiller. Each piece of wood is different, each stave has a different composition from bottom to top. Matched sister billets are more likely to be consistent but it is not a given.
I start with even tiller, shoot the bow, feel the hand shock, watch the arrow flight, run the nocking point up or down and change the position of my hand on the grip.
After the above tests and some things just don't have the "this is right" feel like I think they should, I go to 1/8" positive on the top limb and retest.
Some where along the line everything comes together, I know it and so will the bows future owner.
To make a great shooting bow you have to be an experienced traditional archer, you have to know where you are headed before you attempt the trip. This is not to say a beginner can't make a pretty good bow they will be very happy with but there is a dividing line between good and great.
I didn't read the whole essay or the entire post thread, but what I have read seems like your trying to make it more complicated than it really is. Several members have given you the answers your looking for, but you seem like you have a hard time excepting it? Maybe I'm wrong.
You can effectively change the dynamics of your bow as in which limb pulls the most on nock direction as the arrow is leaving the bow simply by moving the arrow nock up or down the string. I go for a nice even tiller then place the center of the arrow about 1" to 1 1/2" above center of the bow, and try to keep the web between my thumb and index finger as close to actual center of the bow as possible.
On the same note you can also change the strength of one limb versus the other with hand placement. Which ties in with what others have already said about grip placement and grip style (high wrist, med wrist, low wrist) fulcrum or where you grip the bow has alot to do with how it's going to shoot no matter how you tiller it.
It's really that simple and it works, at least for me it does.
Oooops, double post. :knothead:
I think Chris you said it right "it works for me". As eric said no 2 pieces of wood are the same, so unless some one is building a glass composite bow where all the materials are close in tolerance then there will be differences in not just building preferences but also materials.
When I begin to get over 20" draw on a self bow I mark my hand position, arrow rest and string nock. from that point on I pull directly from the nock point and I place a small fulcrum of wood directly under my hand pressure point at the center of my and let the bow pivot a little on that small fulcrum. What this does is allow me to watch the bow balance as it is drawn. A heavy limb one way or another the bow will tip, some times the bow quivers as it is drawn showing there are spots during the draw curve that favor one limb or another. MY goal is to get the bow to start and end balanced, this may not be text book but I have found even with a heavy wood like osage I don't have the hand shock that others do and the bow doesn't torque when I hit to point to quit hanging on to the string. Another thing this does for me is it allows me to snap shoot and from my experience every second you hold a self bow at full draw the slower the bow recovers causing a drop in arrow speed, causing fluctuation in ones shot placement. I need all the help I can get when it comes to shot placement LOL.
In another post I was trying to discuss the real problem with the lower shorter limb of an asymmetrical bow bending more. By building the way I do they almost always come out that way. Even if there is no text book documentation to really support anything absolute, What I found to work works "at least for me".
When traditional archery becomes so mechanical it does not allow personal expression then we might as well regress to shooting the wheelies. Like a fine sports car those that look on with wonder need to be able to see a bow and say "that is a Semo bow".
We both build SEMO bows locationally speaking. :thumbsup:
Just wanted to clear some things up, then i'll lay this to rest. Here's what brought this whole question up for me:
1. Read Dean Torges' article about tillering presenting the idea of negative tiller. Made sense what he was sayin, and seemed contradictory to what a lot of people were doing. i basically got all confrused at this point.
2. Tested the seesaw assumptions and found them erroneous (ie: top limb does NOT receive greater force than bottom limb as Deans example states)
3. Had an aha moment where it all came together. Then i presented another really LONG post to explain WHY many bowyers use positive tiller, etc. to remedy the lower limb bending more on most bows. At this point, I was in AGREEMENT with Roy, Art, Semo, etc as to how the bow should be tillered (and still am!).
I was really just hoping to shed some light on the mechanics of why we're doing what we do so other knuckleheads like me asking the same questions can just read it and not start a big online debate :deadhorse:
I took y'alls advice by the way as i finished up my last two bows, and they came out great. As you can see from those, I really do prefer to keep things simple and elegant :)
I really do appreciate all the input and experiences y'all gave to hopefully help future newbies understand a little better. Nuff said.