Where did positive tiller come from?

[Marc St Louis]

My statement was directed at Pat with equal length limbs in mind, what I usually make with a stiff handle bow.  Taking a stave with no character and tillering it out so that it stays still in the hand while drawing will usually result in a slight positive tiller.  Pat has come and clarified his statement saying that he was referring to unequal length limbs such as longbows, to which I still disagree.

In any case, I agree with Mike.  Hand pressure and how you draw make a difference

[George Tsoukalas]

Oh my! I don't understand all the furor.

Most of my bows have equal limbs. The arrow pass is usually 1.25 in above center but that can vary depending on tiller.

Some do not.

I tiller from the geometric middle of the bow.

The bow comes off the rope and pulley and I check tiller in front of a mirror as I draw it, window at night or have my wife snap a digi. I believe noting approximates how you hold a bow in the hand. That includes tillering from where you draw.

I want the limbs tillered evenly or the bottom limb stiff by about a 1/4 inch at full draw. A few swipes with a scraper accomplishes that.

What really counts is what the bow is doing at full draw. As long as brace is close, i don't care much more than that.

I have made many bows like this and a few with shorter lower limbs All are balanced on the draw and all are balanced when in the hand walking.

The tillering process takes care of variations in design, etc.

There is more than one way to make a bow.
If you want to make the stump end the bottom. Fine. There may be some merit in that. I don't know. I have not tested it. It is not important to me.

If you only want to cut bow wood when there is a full moon. That's fine too. I never tested that either.

Chances are if you think a factor makes a difference it probably will.

Jawge

[Josh B]

I gotta agree with Jawge.  Definitely more than one way to make a bow.  A lot of us are self taught, so there are gonna be a lot of different solutions to problems.  I don't measure for positive tiller, most of the time I don't measure much of anything.  Sometimes that causes me some grief though, I don't recommend that approach.  I can't say that I've ever payed attention to which end of the stave was the trunk end, so I don't know if that matters either.  I know that I should probably take this with a more scientific approach,  but this isn't rocket science for me.  Its just something I enjoy doing as long as I keep it simple.   My great great uncle Fred was a carpenter, but he never owned a square.  His philosophy was" if it looks good to the eye, it can't be to far off".  For the most part, that is my approach to making bows.  Of course I have to add to that,  if it feels good in the hand throughout the draw and release, it can't be far off.  Just my .02.      Josh

[PatM]

It seems the original thought for this thread was that there might be a "better" way of tillering a bow or laying out the limb length but the basic shootability of the bow should be the prime consideration.
 Most people seem to agree that slight positive tiller , however it is believed to be achieved) accomplishes that best. It has stood the test of many years of bowmaking and shooting.
 There is nothing wrong with thinking that you can change all that  and switching things up but you'll very likely come right back to the proven way of doing things.

[SLIMBOB]

That sums it up for me as well Josh.  I have found this post very interesting, as it is good to try and understand why something works.  Positive tiller for me is the result of my tiller not necessarily the goal.  I know that for the bow to be balanced as I draw it, the bottom limb will typically be just a tad stiffer.  I shoot with a lot of heel in my grip, split finger.  I believe that shifts the dynamic center down.  I cant the bow a good bit which I believe shifts it back up some.  If I'm shooting off a shelf I hold the bow a little different than if off the hand, so a formula for me to use or a measurement is out.  Does it balance when it's drawn?  I made a bow a year and a half ago when I first joined PA.  When the tiller was done, the bow appeared weak in the bottom limb, but it shot well.  I popped the shelf off and turned the bow over.  It looked swell in the pic but you could feel that it tipped as you drew it, no bueno.  I turned it back over and posted the pics.  I was chided by a few for the tiller being off as the bottom limb appeared weak.  I simply knew that not to be the case on this bow.  It balanced well, and that is the goal.  No measurements required.

[lostarrow]

It really is very simple.
You put different forces on the bow limbs when you draw the bow by hand.
Bow hand pressure point and the point where you actually pull the string from are what you need to think about and their relation with where actual measured center is on the bow.
Tiller you bow to bend evenly and be balanced at full draw and the lower limb needs to be stiffer.
It really is as simple as that.
I don't understand what you are all talking about! Just tiller the darned bow to be balanced in the hand at full draw. 
This is, always has been and always should be the way to tiller a bow.
I'm saying no more.

 Come on Mike, if it were that simple , the monkeys would rule the world (not sure they don't right now ) I know you said you weren't saying any more ,but............................. you didn't give a reason for why you want the bottom limb to be stiffer. Now we are falling back into the dangerous territory of " we've always done it that way."  I'm not saying it's wrong , It's just that no one has convinced me that it's right.

My statement was directed at Pat with equal length limbs in mind, what I usually make with a stiff handle bow.  Taking a stave with no character and tillering it out so that it stays still in the hand while drawing will usually result in a slight positive tiller.  Pat has come and clarified his statement saying that he was referring to unequal length limbs such as longbows, to which I still disagree.

In any case, I agree with Mike.  Hand pressure and how you draw make a difference

    If I'm reading correctly , and it is difficult to sometimes decipher the nuances of our language in type, you  and Pat are coming  to the same conclusion  from different angles.    If your stiff handle bow that balances in the hand (I'm assuming the bow hand is in the dimensional center?)   is longer below that point to the fades  than it is above that point to the top fade ,the bottom limb is shorter . If it is tillered on a tree while clamped ( stiff handle not moving) and the limbs were tillered to bend the same distance at the tips, the bottom limb will be under more stress.(because of it's length).
   Now, when you take it off the tree, it will pivot in the hand  because you changed the  pivot point thus giving you a positive tiller and a weaker top limb.
   But ,you now have a weaker top limb  ! Not only that, but the bow  is tilting forward at full draw. Mike had mentioned that he tillers his  the same. I'm assuming that his bottom limb/relation to center is the same as Marc's thus giving the same result. This all agrees with what PatM said in the first statement, I believe.
 
  Sorry but it still doesn't provide sound reason to make the bottom limb shorter from fade to nock and make it stiffer to compensate. I'm not saying it doesn't work , it obviously does . I've been building them the same.  But the top limb is obviously now the weak link in the chain , instead of taking it's share of the load. This would seem to be the answer to Del's question of why they break on the top limb .
 
  When it comes down to wood bows breaking, the sad truth is , they will all eventually break . If they didn't , we would have a huge array of historical examples to learn from. The ones that get used , break. The better the stress is distributed the longer it will last. The bows Del is talking about at his club likely get used very often (once a week?)  Most of us don't get the chance to do that . Some of us own several bows and change it up  even if we do go often.

  Now ,...... what problem  would there be with truly tillering the limbs the same. I can't see any ,but maybe I'm missing something. I can only think that it would add longevity and shoot as well or better.
Arguments for and against  would be appreciated, even if hypothetical. 
   
       

[George Tsoukalas]

lostarrow, most of us shoot with a split finger draw which puts more strain on the bottom limb. The idea is making it a little stiffer and stronger will compensate.
Jawge

[PatM]

 Make a bow with a positive tiller and then flip it over and se if you like it better upside down. The proof is in the shooting.
 

[lostarrow]

Pat, I'm not saying it would be  better to have a positive tiller on top or bottom . No " one limb stiffer than the other" at all. Just two balanced limbs with no positive tiller.

[bubby]

I think it was started by some trouble maker to have a good argument while drinking beer around the fire 

[PatM]

That's fine but getting the limbs to stay balanced with the different stresses from drawing is what seems to be the issue.
 You can build the bow that way, but can you keep it that way?

[lostarrow]

I'm not sure but I know I'm going to try . We'll see what happens. Thanks for all of the responses guys!

lostarrow, most of us shoot with a split finger draw which puts more strain on the bottom limb. The idea is making it a little stiffer and stronger will compensate.
Jawge

I think we've determined that it's dependant on the layout of the bow . It doesn't have to be stressed more , it's only when you make the bottom limb shorter .

I think it was started by some trouble maker to have a good argument while drinking beer around the fire 

Just as good a guess as any I've ever heard

 As far as doing it the traditional way,  I'm all for it! The problem I have is.......... Who here has definitive proof that they are doing it the traditional way. In the recent past, we've all but lost  the information.I think we can all agree that a lot of B.S. gets thrown into the mix when someone say's" that's how my granddad used to do it"! As  Josh pointed out , a great deal of what we've relearned ,is self taught, and gleened from the tidbits we could gather from any source we could.  (not neccesarily reliable) I used to have a book about how to make a bow, written by an Englishman about 1940-50 or so. I remember him saying to make the tips heavy , because this will help cast the arrow farther and make the bow shoot better. this was the sole purpose of adding horn nocks .Not such a great book , but the only one I had ever seen to that point. (pre internet, and primitive archer was very new on the scene. Almost impossible to find here.)
   I've been working with wood since I was about 10 ( wonderful parents that encouraged that sort of thing) I was given a knife when I was about 6-7 years old and spent most of my "play time " wandering around the bush, which was plentiful where I grew up. I've always been keen to learn how to do and make stuff and with a large extended family, Aunts and Uncles that grew up as self reliant pioneers ,I had plenty of teachers. I studied cabinetmaking and learned how to do the tasks in the traditional manner , before applying the machines. I feel this is a good approach with everything. I have also worked with many that had three time the experience ,but never really learned very much. These were also the fellows that were expected to teach the apprentices. Don't feel I'm trying to buck the system or   throw tradition to the wind( If I was I wouldn't be making wood bows ) I'm also not trying to set any records, or get my name in any books. I just feel that some of the convention we follow may not be done with sound reason. It may be a good rule of thumb in one case and complete nonsense in another.
  Once again , thanks for the input everyone! I feel  this was a fruitful exercise and no one got their feathers ruffled. Makes me proud to be part of this group!