Positive tiller guys, how much do you do? 1/8"? 1/4"?

[toomanyknots]

I dont think a bow should move at all in a year if its properly built and braced. I was thinking general use after 5,6 or even 7 years of shooting it. I didnt say your bows are tillered wrong, I wouldnt know if they where. A given bow, in general, shouldnt take on set that quickly if its tillered well, built well and braced correctley. The few bows I have made that "caved in" as I call it had design issues, and or tiller issues. Most have been fixed with reheating and retillering, as most of the worked wood is removed.

Your taking what I'm saying out of context. When I said was I was having problems with my bottom limb weakening over time, I never said the bow was caving in or taking any noticeable set. I had been using about 1/16" lower of positive tiller on the bottom limb, and after a bit of time, the bottom limb was weakening, to where at brace height the string was even, or 1/16" lower on the upper side at most. Which undoubtedly was causing trouble with balance when the bow was drawn (unless flipped over like PatB mentioned) or lowering the arrow pass a bit to center. Which is of course no problem with a cord wrapped handle like I will typically use, or naked handle, like on a naked elb. But with a static arrow pass or shelf, it can become an issue. This is with the arrow being shot about 1/2" above center. Not tooting my own horn or anything but I do know what a good tiller looks like, and am quite aware of what an under built bow looks like, so I do know that was not the problem.

[PEARL DRUMS]

So if a weakening limb isnt "caving in" or taking set, what is it called when the tiller changes by a 1/4"?

[Roy]

F'ed up...

[toomanyknots]

So if a weakening limb isnt "caving in" or taking set, what is it called when the tiller changes by a 1/4"?

Math never was your best subject, was it. 

[PEARL DRUMS]

For the record Im not trying to do anything more than help you figure out why your limbs do this, its not normal and adding a more positive brace wont fix it for you. I can shut up and you can continue on with your quest if you want me to. Its no problem here.

[steve b.]

Why do we judge the tiller of bows on this site by looking at pics of them if the real tiller should be measured down to the 1/16th inch?
I never see anyone say that a bow's tiller looks good but make to measure that tiller before calling it good.  Never.

[PEARL DRUMS]

Just thought of a possibility TMK. Of the bows that you noticed the change in, where any of them osage with sapwodd left on? Maybe just maybe leaving sapwood on osage staves is the culprit. Maybe the weaker sapwood is giving way to a stronger belly of heartwood?

[toomanyknots]

For the record Im not trying to do anything more than help you figure out why your limbs do this, its not normal and adding a more positive brace wont fix it for you. I can shut up and you can continue on with your quest if you want me to. Its no problem here.

Oh come on, it was just a little joke. I said 1/16", you said 1/4", etc etc...     Anyway, Yes the bottom limb I guess is taking set here, you are correct, what I meant is that neither limb appeared to take any measurable string follow most of the time, (pretty sure anyway) and I guess set would be the wrong word to use here. (It's 5 hours before I usually get up at 4:00 PM , gimme a break yall,  ) And yes, all bows that I had do this on me I have fixed by weakening the upper limb, effectively producing a more positive tiller. Which I am stating to think I should of done in the first place.

[PEARL DRUMS]

Maybe some more exercise time as you tiller can work it out also. Maybe the bow isnt being tested enough prior to full draw and the changes register too late.

[FlintWalker]

I usually start with around 1/8" pos. on the top limb. Then I just shoot it and see what it feels like. If it needs more or less I can usaully feel it and see it in the way my arrows are flying. I usually end up around 1/4" pos.  on top for shooting split finger. Shelf is about 1-1/4" above center. I don't care what it looks like.If it don't shoot good, it's just fancy fire wood.

[Pappy]

You are correct steve b. that's just the way I do it,not saying everyone should.
 Lord know I believe their are many way to skin a cat,just good conversation.If you want to do it all by eye then by all means do it. I will keep my ruler.
even a bad tillered bow will hit the same make everytime if it is pointed and held the same using the same arrow.   enough for me,don't know why I get into the conversations. I need to go to work.
   Pappy

[Roy]

Cause they are fun conversations, Pappy. Like a dog chasen his tail:)

[toomanyknots]

Just thought of a possibility TMK. Of the bows that you noticed the change in, where any of them osage with sapwodd left on? Maybe just maybe leaving sapwood on osage staves is the culprit. Maybe the weaker sapwood is giving way to a stronger belly of heartwood?

No, mostly hackberry and red oak. Plenty of people make sapwood backed osage bows. Also that doesn't make any sense why one limb would be stronger than the other? I think it a more likely conclusion that I have not been allowing enough positive tiller with only 1/16" of an inch, and seeing as most people use a good amount more, from an 1/8" of an inch to 1/4", I have assumed this to be the case. As well as when put in practice for me, it seems to hold true. If there were any tiller or design problems with the couple bows I have had this problem with like you have proposed, I would of taken that all into account. Although I fail to see why positive tiller and balance are not parts of a bows design? Either, thank you for your advice.

[Pat B]

Ballance is important. I just don't use a measuring tool to measure the tiller.  There are other things to think about...how you grip the handle and whether you shoot split fingers or 3 under.

[Roy]

Now your learning toomany.. At least 1/8th to start.