tillering for balance and "timing"

[jwillis]

Do the limb tips need to pull the same distance at full draw regardless of bow grip location relative to bow center and string pulling location relative to string center? For example, equal vs. unequal length limbs, and split finger vs. three-under pulling styles. Jim

[George Tsoukalas]

No matter the type of bow the first 6 shots are for sensing the balance. Is the pressure even on the handle as I draw or are the limbs tippy. How does it feel on release? Do the limbs slam home together (thump) or one at a time (thump, thump). I do like the bottom limb just a little stiffer  at full draw by a 1/4 to a 1/2 inch. Jawge

[jwillis]

I know that we have beaten this horse many times, but the issue is still not completely resolved in my mind. I've made a lot of bows a lot of different ways and I still have not resolved this issue. I have read everything that I can find on this subject...archery forums, magazine articles, instructions materials, books, etc, but have never found a comprehensive guide. There is a lot of misinformation, mistakes, and just plain confusion available about this subject. If someone knows of a clear and concise guide, please point me to it.

It just seems that if we are making a bow with positive or negative tiller to create dynamic balance for a certain shooting style, grip location, string location, limb length, etc, that it forces the limbs to be different strengths. If the limbs need to pull to the same distance from the back of the bow at full draw in order for them to be equal strength and return to brace at the same time during the power stroke (effectively canceling out any possible vibration), then creating positive or negative tiller is forcing us to accept at least some vibration in order to achieve dynamic balance. If this is true, it seems that anything other than a bow with equal length limbs, grip at bow center, and string pulling location at string center requires a compromise between balance, performance, and possible reduced limb longevity.

If the limbs don't need to pull the same distance in order to return to brace at exactly the same time, then please confirm that. I can't seem to understand how they could possibly pull to different distances and then return at the same time. I have read a lot of debates about this issue...they are tied together by a string so they must return together vs. they return at different times vs. they travel different distances at different speeds, ect. Maybe I'm just missing something obvious here?

Jim

[George Tsoukalas]

This is quite an issue for you, jwillis. I'm afraid I can't help you much beyond what I do. I usually place the arrow pass 1.25 in above center but this is not written in stone,  That coupled with the slightly raised nock point means I pulling close to center.  I tiller the  bottom limb just a bit stiffer to counteract any additional strain the split fingered draw may  place on the bottom limb.  Again the first few shots are important. BTW my preferred design is 2.5 in on either side of center for a 5 in handle but have tried many other handle types. That's it. Nice and simple. Jawge

[jwillis]

George you're a real nice man...lol. Thanks for the grace. I just realized the error in my thinking...DOAH. Looks like I had another brain fart. Since I'm pushing the bow and pulling the string at the contact points of the archer on my tillering tree, then I am correct in tillering the limbs until they pull the same distance. If I were to move my bow to the center and pull from the center of the string, then the bow will show the correct positive or negative tiller and limbs will not pull the same distance. Sorry if I created any confusion. Jim

[Jesse]

The sweetest shooting bow I ever built had even tiller and the throat of the grip where you put all the pressure was dead center. Arrow rest was 1 1/8 above that.
 I learned to trace  the belly of one limb at brace on a table then flip to the other limb and make sure its bending the same along the whole bow. Not just that the tips end up at the same place. Hard to do it good enough just by eye. Of course this doesn't apply to a character bow. 

[Pappy]

I do about like Jawges except 1 1/4 each side of center,Bottom limb a little stiff 1/4 to 3/8.
I then shoot it,holding it where it feels good and move my hand up and down the grip a little as I shoot and see where it feel and shoots the best,I then mark it and that is the arrow pass.
No problem for me but I am a pretty simple guy anyway.I try not to think to much. Gives me a headache.
   Pappy

[Del the cat]

This is actually a great Q.
I agree that there is an awfull lot spoke about it which isn't clear.
My take is that I try to tiller supporting the bow pretty much at a point (free to rock) where it will be supported by the hand and pull it back where the fingers below the arrow will be (I even have a two pronged hook on my tiller rope.
This can show up some weird rocking movement very early in the draw, eg the top limb tends to pull down at the start because the fingers are above the grip point. I think this allows a good feel of how the bow will work. HOWEVER, in order to see if the limbs are moving evenly I compromise a tad and support the bow nearer the arrow pass so the tips starts horizontal and finish horizontal.
I find a problem when people say 'stronger by 1/2"' I can't actually visualise how this is being measured, and I think that one man's 'stronger' could be construed a 'weaker' by someone else.
I think we need very clear concise unambiguous explations.
Of course  'clear concise unambiguous' is difficult on a curved bow with no good solid frame of reference.
I'd suggest a line extending through the grip, and the grip pressure point or arrow passare the only stable frames of reference.
I'm glad you posted as I think it needs some good discussion.
Del 

[Pappy]

My 1/4 to 3/8 stiff is usually measure at brace ,along the limb length at 3 or 4 inch
increments. Of course it depends on the stave,Character starves you can throw that out the window. Some say at brace don't matter it is at full draw that counts,that is true but I have found if you keep it close to where you want at brace,full draw will follow.
   Pappy

[Del the cat]

My 1/4 to 3/8 stiff is usually measure at brace ,along the limb length at 3 or 4 inch
increments. Of course it depends on the stave,Character starves you can throw that out the window. Some say at brace don't matter it is at full draw that counts,that is true but I have found if you keep it close to where you want at brace,full draw will follow.
   Pappy

Just to clarify, that's lower limb closer to the string than the upper limb (at brace)....right?
Del

[George Tsoukalas]

Key phrase "tillering for balance and timing".  The design doesn't give you balance and timing. The tillering does. Anyway, I don't care what the stave does at brace. I want the bottom limb a 1/4" stiffer at full draw. This becomes particularly important with character staves not so much with others. Jawge

[Badger]

I used to tiller the bow by drawing it back as my fingers would and watching to see if the arrow comes straight back and returns staying level. Now I figure it is where the atring is when I let go of it that counts so I draw it back where the arrow fits on the string and look for it to stay level their not paying too much attention to positive or negative tiller. Steve

[bucksbuoy]

Despite all our best efforts you will always feel a natural hinge or pinch at your grip point. This is the "working center" of the bow and you typically want to aline your working center with the actual center of the bow and shoot an inch or two above it. If you are a vulcan and prefer to strangle the bow then this pinch point will be more towards the bottom of your hand and you will nedd to shoot 3 or four inches above true center and definitley wear an arm guard. Essentialy the center or the bow is were you hold it. Not were you shoot from. I can still remember I was 12 years old sitting in a barbers chair with severe back lash on my arm when this was explained to me. hahahaha!