"which tiller is better for what?"

[willie]

In another thread, a discussion has me asking why I would want my tiller shape to be more circular or elliptical. Or put another way, why would I choose to make a parallel limb bow with a thickness taper, over a pyramid limb bow with a constant thickness limb.

Does one limb design shoot some kinds of arrows better than others? I am wondering which would be better for heavy arrows, and which would be better for lighter arrows. and why it is so. Does the tiller shape itself (circular or elliptical) make the difference? Or is tiller shape secondary to why one kind of limb works better for some arrows?

[Badger]

    Pretty much a toss up for a straight limbed bow. Pyramid is a great design and simple. I prefer what I call a semi pyramid or semi parallel. I build the bow with parallel limbs but refine the side tapers as I near completion of tiller. I try to remove mass from the outer and mid limbs when I can spare it. The parallel limb take better to the r/d designs we see so much of now I feel although I have seen plenty of pyramids that were r/d as well.

[sleek]

I build a hybrid of parallel and pyramid.  The first 7 inches after the fades is parallel the goes to pyramid to the tips. Then I work on narrowing the last 7 inches of the tips down to something of a eiffel tower profile. Not all i build are like that but most are.

[Carson (CMB)]

Looking at the extreme end of the spectrum, there are examples of highly whip-tillered yew target bows made to shoot very light cedar target arrows, and then there are bend through the handle longbows of the tropics that are made to shoot heavy long arrows. I see it as the mass in the limb moving forward relating to the mass of the arrow being shot, though it might not be that simple.

[sleek]

I think you got it 100%... for whatever my opinion is worth on that...

[BowEd]

Really I personally think the goal would be is to get the energy storage of the limbs to be on the inner two thirds of the bow tillering well to take as little set as possible[so parallel limbs go there] and the outer third[narrowed but thickened] to be lighter but stiffer.Not doing much work at that position of the limbs so it's not stressed and retaining any reflex put to it.A bow like that will shoot any kind of arrow fast I feel.The full draw look on a bow like that will look more elipse if not reflexed much.Working almost right into the fades.Refining it to be a more streamlined lever type bow with the transition to the levers.It's the way I've been building bows for quite some time now.If it was reflexed it could be called a reflexed lever bow.These type bows don't conform to any type of tradition or culture but shoot very well for me.They conform to Tim Bakers' way of thinking.Carsons' point I agree with as a whole too.
So your gonna have to find through making and testing what you like and what works for you.

[willie]

Looking at the extreme end of the spectrum, there are examples ......

I like Carsons  idea of looking at the extreme ends of the spectrum, but perhaps there are examples of both styles that shoot light arrows well?  Steve mentions a toss-up, and I presume that is an opinion formed from his observations of winning shots in  light arrow flight shooting?

As for the opposite extreme, are there events that shoot heavy grain per pound arrows? What do the shooters prefer?

I find it hard to draw conclusions from the tropical bows that shoot long heavy arrows, their low strain design bows might just be the best they can do with their humidity problems. Same with supposing "what might have been" with the warbows of hundreds of years ago.

[BowEd]

The only event I know of is just hunting as far as shooting heavy arrows go.The mantra Tim continually speaks of pretty much holds true for efficient type bows and that's where it's at.Although there are plenty of master type bowyres on here that do it with different styles of bows.

[Badger]

  Willie, I compete with 500 grain broadhead arrows at the flight shoots which are hunting weight arrows. The only real difference with the light flight arrow  bows is that they tend to be slightly shorter and we might pay more attention to taking mass out of the outer limbs. My longest light arrow shots have always been in practice and they were always with regular hunting bows as opposed to the lighter flight arrow bows.

[Badger]

Really I personally think the goal would be is to get the energy storage of the limbs to be on the inner two thirds of the bow tillering well to take as little set as possible[so parallel limbs go there] and the outer third[narrowed but thickened] to be lighter but stiffer.Not doing much work at that position of the limbs so it's not stressed and retaining any reflex put to it.A bow like that will shoot any kind of arrow fast I feel.The full draw look on a bow like that will look more elipse if not reflexed much.Working almost right into the fades.Refining it to be a more streamlined lever type bow with the transition to the levers.It's the way I've been building bows for quite some time now.If it was reflexed it could be called a reflexed lever bow.These type bows don't conform to any type of tradition or culture but shoot very well for me.They conform to Tim Bakers' way of thinking.Carsons' point I agree with as a whole too.
So your gonna have to find through making and testing what you like and what works for you.

      I don't like set anywhere on a bow. I like to think of a bow being 3 seperate parts, handle, springs and levers. The least amount of spring you can get away with the better because it causes problems in every other aspect of the bow besides supplying the raw power. If the levers are designed right they give the leverage back to the arrow so the arrow can slow down the arms as it is coming back to brace. The limbs are not supposed to slam home as is often said.

     If you are to compare bows built right here on PA to the bows shot at the first mojam, these bows today would far exceed the speed they measured then. Your best references are looking at the present day bows. The bow that one that contest would be ok by todays standards but nothing special.

[willie]

Thanks Steve. Flight shooting sounds like fun, and there must be a lot more involved than design.

[mikekeswick]

From a scientific point of view a given piece of wood can bend so far without taking set. Make it thinner - it can bend further. Make it thicker - it can't bend as far.
No set inner limb, a fraction midlimb and the rest out to the tips.
you can work it all out from that

A pyramid (theoretically!) should have automatic even strain as the wood will be the same thickness, therefore should all be bending the same amount, same bend same strain. Parallel width limbs need some thickness taper and therefore require a little more skill to distribute the stress evenly.

[mikekeswick]

Then once you have all that sorted you can start to make bows that will shoot light arrows best (light,fast moving limbs) and bows that will shoot heavy arrows best (elb's long,slower moving limbs).

[Badger]

Then once you have all that sorted you can start to make bows that will shoot light arrows best (light,fast moving limbs) and bows that will shoot heavy arrows best (elb's long,slower moving limbs).

  Mike one thing funny about shooting the light arrows is that none of the very fast flight bows I have built so far have really gotten any great distance because of arrow flight and release problems. Overall little 62" pyramid style bows with a little reflex and real light thin out limbs seem to score better even though they don't have quite the speed. Most of the records set are set using simple designs.

[willie]

Most of the records set are set using simple designs.

Thanks again Steve. Something to contemplate

and bows that will shoot heavy arrows best (elb's long,slower moving limbs)

Mike, if this is your experience, please take a moment and say why you think it's so. Is it because of the tiller profile, or other reasons ?