three under tiller

[fujimo]

hiya all
could someone explain to me the differences in tiller between split finger, and 3 under, if i was to take a well tillered split finger bow- osage self bow, bend thru the handle design- currently 60#, and re tiller it for 3 under( and i want to shed 10 lbs of draw weight )- what would the fundamental differences be, and how should i go about it??
thanks
wayne

[bigcountry]

IMO, you want the top limb bending more (stronger bottom) with a split finger tiller.   I used to tiller my bows even because I shoot 3 under, but found the bow is not balanced still with 3under, and give the top limb an extra 1-2".  That way it naturally appears to be bending more if both bottom and top have the same bend.

[fujimo]

this is how my bows are tillered right now- the top limb, is 2 inches longer than bottom limb, and the bottom limb has about 1/4 positive tiller- ie, it stiffer than top limb.

[bigcountry]

I have been experimenting lately looking at tiller with various hand placements.  In my opinon 1/4" positive is perfect for 3 under, and even more needed with split finger.  I could be wrong.  

I do know my bows that are even tillered are not balanced well when I draw and I have to nock lower than usual.

[hova]

i dont get how you can shoot three under. i tried it and it feels like i might as well shoot 4 under.


i tiller all my bows to even on the stick , then adjust for feel. tiller is like salt and pepper...to taste...

-hov

[bjansen]

Fujimo, try searching the bench for three under tiller.  There has been at least 1-2 long strings of posts in the past about it...with all kinds of various viewpoints and theory.  You'll find some great info in the search.

[John Scifres]

Here is how I would do it.  Find the sweet spot for shooting it now 3 under.  Mark where your middle finger lies on the string.  

Then use a pulley-style tillering tree and put your hook where you marked your middle finger.  Start reducing weight gently with a scraper.  Count your scrapes 10 at a time.  

Exercise it to 25" 30 pulls and check tiller and weight after each round until tiller is perfect and weight is 3-4 pounds over your target.  Find the sweet spot again and repeat tillering.  Finish it and shoot it.

  Tillering Tutorial

As far as "fundamental differences", you will have 3 fingers under the arrow instead of 2