Well since I can't stay out of controversy with my threads I figured I better post something a little bit less controversial.
I shoot 3 under style and have for about 7 years now. Through the years I have done several different things with my Bows to try to get them to shoot and tune well. I've been shooting TallTines and have been having Brian make me a bow that has an even tiller and have been doing relatively OK with tuning. I've had to have a very high knock point though. Recently I bought a used bow on the classifieds here and swapped the bottom and top limbs which were tillered for a standard positive 3/16" tiller. By swapping them I've ended up with a -3/16 tiller and let me tell you it shoots excellent! Much much quieter and for the first time in several years I can bareshaft really well without nock high issues. I was shooting bare shafts perfect out to 20 and 30 yards tonight
So, should I have Brian build a 3/16 negative tiller on my next limbs? What would you guys recommend? That or just have him build a standard positive tiller like these and flip the limbs.
Here is a picture of me shooting an even tiller a few years ago, see how my bottom limb is overloaded? Would this be better if I had a negative tiller?
(http://i792.photobucket.com/albums/yy206/cottonwood88/Mobile%20Uploads/image_1.jpg) (http://s792.photobucket.com/user/cottonwood88/media/Mobile%20Uploads/image_1.jpg.html)
I shoot split finger, and I have all my bows tillered even. Even just seems to shoot best for me. You might have a hard time talking a bowyer into purposely making one "out of tiller" like that!
Bisch
What did Brian say about it? I'd imagine him or other qualified bowyers would have tried that by now but there must be a reason negative tiller is not a more common practice
It would be interesting to have some bowyers chime in
If you will indulge me, I really don't understand tiller as well as I would like to. Even tiller means the measurement from the fades to the string is equal top and bottom. Easy enough. Negative tiller means the measurement from the top fade to the limb is less than the measurement from the bottom fade to the limb, right? Doesn't that mean the bottom limb is bending more at brace height than the top limb? If it is bending more, does that make it the weaker of the two limbs? If it is the weaker of the two limbs, why would it work better than even or positive tiller when you put more stress on it by shooting 3 under?
I'm not saying that my statements are correct, necessarily. I would just like to know where my thinking is out of kilter.
He actually mentioned flipping the limbs to see how it shot.
My new Black River bow from Will Cocke is tillered for 3 under.
I requested it tillered 3 under, and this is what it measures.
7 1/16 bottom limb dimension from string to limb, at riser end.
6 7/8 top limb dimension from string to limb. At riser end.
So it is 3/16 difference.
And personally will always go this way in the future if I am ordering a bow.
Easier to tune in my opinion and quieter in my limited experience with this one bow.
I am with you McDave. It seems if the fingers are lower on the string they would pull more on the bottom limb and the bottom limb is already bent more.That is the way positive and negative tiller is,and the way it works. I don't understand why.
>>>-----> Ken
Michael, in the pic it appears you are putting the majority of your finger pressure on the long and ring finger so more pressure well below the nock point like a fixed crawl requiring a high nock point to compensate. I shoot a negative tiller with a fixed crawl on my ILF rig since it is quieter and smoother and uses a lower nocking point.
Sending a link to another site for a good read on tiller to you and Mcdave.
Michael, if 3U is even tiller what would flipping the limbs do? Wouldn't it be the same tiller unless he tillers differently for 3U than other bowyers? Did he discuss anything about what he does differently for 3U vs split?
On my bows (& most bows) switching the top and bottom limbs is not an option. Obviously not with a 1pc either
Interesting thread
It is common advice for people that shoot three under to raise their nocking point when shooting a bow that is tillered for split. This would increase the leverage arm on the lower limb. That would be the same as flipping the limbs as Michael described.
Or am I missing something here?
(md126- I believe Michael is saying that he bought a used bow that was tillered for split and switched limbs.)
I shoot 3 under and adjust for negative tiller with my ILF recurves. At least 3/16 negative. My nock points are lower and my arrows sit flat. Before trying ILF, my nock was pretty high and the arrow looked like it was pointing down hill.
Well, first let's consider the point of "tiller". It is an attempt to get both limb tips to hit the end of the string at the same time, period.
In a perfect world the fulcrum of your support hand would be the center of the bow, but that is seldom the case.
Then consider where the center of force is in relation to that fulcrum point. Three under moves it down.
Your bowyer should be able to graph out exactly what tiller is needed based on how you shoot his bow. Talk to him.
QuoteOriginally posted by McDave:
If you will indulge me, I really don't understand tiller as well as I would like to. Even tiller means the measurement from the fades to the string is equal top and bottom. Easy enough. Negative tiller means the measurement from the top fade to the limb is less than the measurement from the bottom fade to the limb, right? Doesn't that mean the bottom limb is bending more at brace height than the top limb? If it is bending more, does that make it the weaker of the two limbs? If it is the weaker of the two limbs, why would it work better than even or positive tiller when you put more stress on it by shooting 3 under?
I'm not saying that my statements are correct, necessarily. I would just like to know where my thinking is out of kilter.
McDave, I'm only a beginner bowyer but from what I understand and from my very small time spent making bows so far, you want the bottom limb to be longer and weaker at brace because when you draw it you are dynamically increasing the stiffness of the bottom limb (just the same way as if you shortened an arrow) because you are increasing the rate at which it bends when drawn.
The top limb needs to be made shorter than the bottom limb because it becomes dynamically weaker since you are drawing the string further away from the top limb.
If you left the bottom limb as long or stiff as the top limb when shot 3 under the top limb would not bend as much as the bottom limb which would throw the limb timing off which makes the bow draw harder and louder.
Someone please correct me if I'm wrong.
What everyone seems to miss is when you hold the bow the fulcrum is an inch or more below center effectively shortening the lower limb. Also with a 2 or 3 under hold the fingers are in line with the lower fulcrum point. The lower limb gets pulled further back so it is in effect pulling at 29" while the top limb is pulling 28". So if the top limb is pulling 50# the bottom limb is pulling 2-3# more. This causes the nocking point to go downward on release and causes the arrow to bounce up off the rest. I've seen this with my high speed videos. Once the pressure on the lower limb is reduced with negative tiller the nock travel straightens out and the nock point can be lowered.
Thanks for the comments. It makes more sense to me now.
I've taken video of myself shooting and find that on some bows my bottom limb sometimes kicks forward at release. I'm sure it's due to my release to some degree but now I'm thinking a lot has to do with tiller. Interesting
Any thoughts fellas?
One would think that this issue would be addressed by some of the many professional bowyers that are members of Tradgang.
Michael:
I think you are on to something. I shoot three under and most of my bows are even tiller. On the even (and positive) tiller bows, my nocking point is pretty high and the bow is still a little loud.
I have one bow that requires a much lower nocking point and is very quiet. I didn't know why but just checked and it has a negative tiller.
" Alex....I'll take BenBow for $1000"
QuoteOriginally posted by katman:
Michael, in the pic it appears you are putting the majority of your finger pressure on the long and ring finger so more pressure well below the nock point like a fixed crawl requiring a high nock point to compensate. I shoot a negative tiller with a fixed crawl on my ILF rig since it is quieter and smoother and uses a lower nocking point.
Sending a link to another site for a good read on tiller to you and Mcdave.
send it to me too! ;)
The other thing that can cause the bottom limb to kick out is a high wrist grip and or pressure on the lower palm of the hand. This puts additional stress on the bottom limb. I learned to shoot bone on bone to get a steady hold and this put more stress on the lower limb. The tillering rule of thumb needs to be thrown out period! Unfortunately most bowyers go by these old rules of thumb and some become violent when told it's junk.
Yupper, Ben. I tiller for equal limb timing, which generaly results in a zero or 1/8th negative tiller.
The degree at which tiller makes a difference for an individual, depends on how blocked his fingers are on the string or not. Some three under shooters put more load on the ring finger which, of course, puts more load on the bottom limb. The advantage of finding the right balance in fingers and limb is that tuning does not need to take extra leaps to get arrow flight. As example, with an even tillered bow, a three under shooter here found that with the addition of an arrow rest only needs to have his bottom arrow nock set 1/8" above the arrow rest to get perfect flight. He shoots with more load on his index finger than his ring finger as well. Of course, I also tell guys to try shooting with a bow sight before starting off on all kinds different forms. I have seen individuals have excellent gains using the shoot through sights, like the DAS system.
Rick****** suggests adding an additional piece of leather under the index finger on a tab to take pressure off the lower fingers. (Funny he must not be liked around here)
I think if you have found a tiller that works well for you, you should stay with it. I have bought and sold bows that I didn't like the tiller. I have also had the same bows, same model all have different tillers - strange but true.
I like about 1/8" positive.
If you can time the limbs to the way you shoot that is best, what Roy said, but not always easy.Even if the tiller looks good once you let the string go the limbs might not return the same, but that gets far to technical for me. Look at a Yumi bow, top limb is much longer but if timed right it works fine.I also think a bow with a little positive or negative tiller can be easily tuned no matter how you shoot.
Finger pressure on string and pressure point on grip will also effect limb timming.
send it to me too! [Wink] Done.
I believe you are right about the pressure in my 3rd finger/ring finger
QuoteOriginally posted by pavan:
The degree at which tiller makes a difference for an individual, depends on how blocked his fingers are on the string or not. Some three under shooters put more load on the ring finger which, of course, puts more load on the bottom limb. The advantage of finding the right balance in fingers and limb is that tuning does not need to take extra leaps to get arrow flight. As example, with an even tillered bow, a three under shooter here found that with the addition of an arrow rest only needs to have his bottom arrow nock set 1/8" above the arrow rest to get perfect flight. He shoots with more load on his index finger than his ring finger as well. Of course, I also tell guys to try shooting with a bow sight before starting off on all kinds different forms. I have seen individuals have excellent gains using the shoot through sights, like the DAS system.
Thank you for this insight. I've always wondered why my selfbows shoot better with most of the pressure on my index finger. The difference in consistency is huge. Didn't know why but just did what worked. Makes a little more sense now.
Benbow, insightful posts. Where I disagree is with your assessment of the bow hand fulcrum and virtual bottom limb length.
The static fulcrum (the balance point before we begin the draw) is the center of the bow.
Then during the draw, the dynamic fulcrum under the bow hand follows equilibrium, which is dictated by bow design, tiller, and our holds on bow and string. In my bows, the dynamic fulcrum stays between bow center and string fulcrum. It would only be below center if the bottom limb was much too strong and I was greatly heeling the grip. Not my idea of a balanced draw.
So mine moves slightly 'up' from bow center toward the string hand fulcrum, which are less than an inch apart, making the virtual bottom limb length longer at full draw than it was, not shorter.
How far it(dynamic fulcrum) slides in any particular setup, and whether or how much it changes the lengths of the virtual limbs/levers, depends on many factors, some already mentioned in this thread.
You can situate or reveal the position of the fulcrum, and virtual limb lengths, by placing something under the handle so that it creates a single point of contact, and move it around until the bow balances on it as it's drawn. If not where you want it, adjust limb strength. Of course, while pulling the string how it will be pulled when shot.
I would love to be able to post a link to a great read on tiller but it would violate the rules as it is a link to another forum. Anyone who would like the link let me know and I can pm/email it to you.
QuoteOriginally posted by Bowjunkie:
Benbow, insightful posts. Where I disagree is with your assessment of the bow hand fulcrum and virtual bottom limb length.
The static fulcrum (the balance point before we begin the draw) is the center of the bow.
Then during the draw, the dynamic fulcrum under the bow hand follows equilibrium, which is dictated by bow design, tiller, and our holds on bow and string. In my bows, the dynamic fulcrum stays between bow center and string fulcrum. It would only be below center if the bottom limb was much too strong and I was greatly heeling the grip. Not my idea of a balanced draw.
So mine moves slightly 'up' from bow center toward the string hand fulcrum, which are less than an inch apart, making the virtual bottom limb length longer at full draw than it was, not shorter.
How far it(dynamic fulcrum) slides in any particular setup, and whether or how much it changes the lengths of the virtual limbs/levers, depends on many factors, some already mentioned in this thread.
You can situate or reveal the position of the fulcrum, and virtual limb lengths, by placing something under the handle so that it creates a single point of contact, and move it around until the bow balances on it as it's drawn. If not where you want it, adjust limb strength. Of course, while pulling the string how it will be pulled when shot.
I respect your opinion but I rarely see anyone shooting with a straight wrist where the bow pivots. It's almost always held with a bent wrist which puts the pressure point an inch or so below center. Tillering from a pivot point is not natural nor common so tillering that way in my not so humble opinion isn't the best way.
UPDATE: after reading the last paragraph again it reaffirms my respect for your insight.
'Tillering from the pivot point'. If that is to mean... tillering by supporting the bow on the tree by the intended or actual dynamic fulcrum which will allow the bow to lean left or right, drawing from the spot on the string that the center of finger pressure will be, and then balancing the strength of the limbs so the bow sits level? I agree it's not common, but in my experience common isn't always right or best.
The bent wrist doesn't put the pressure point below center or anywhere else on its own. It's just one factor in the equation. The fulcrum's location could still be put where you want it by way of design, relative limb strengths, and how the string and handle is grasped.
For instance, I shoot with a bent wrist and my pressure point/fulcrum point is above bow center and handle center from the time I begin the draw, to anchor.
Easy enough to check one, stick something under there where you believe your dynamic fulcrum is, and draw it on the tree. You may or may not be surprised where the fulcrum actually is. I know I was at first.
Nothing but due respect from here too, bud.
Imagine two doors on the same wall. Slam both doors shut at the exact same time and there's very little noise, vibration, etc.
Slam one shut, then the other. There's more noise and more vibration on the wall.
The ideal tiller is to have both doors (limbs) slam shut at the same time.
There are so many variables it's "almost" impossible for a bowyer to get it right on a laminated bow unless the customer is there with him. Pressure on the string, grip with more pressure on the web, heel, or middle of the hand. How about nock location?
It's not unusual at all to find a negative tiller works better for you. To my notion, a lot of folks would fair better with a negative tiller.
I agree, Jim. Unfortunately, folks are told to avoid negative tiller like the plague, and they do.
QuoteOriginally posted by Bowjunkie:
I agree, Jim. Unfortunately, folks are told to avoid negative tiller like the plague, and they do.
X2