3-Under and tiller question?

[CUJO]

I would like to hear the theory of some of the bowyers that go equal tiller?

Marc

[autumn spirit]

Interesting post.  I recently started mess'n round with three under and was impressed with the accuracy.  However, not so impressed with the increased noice level.  I was telling a friend about my experimenting while at the range a few days ago, so he thought he would give her a go.  His comment after putting two arrows through his Widow....too loud.

[Pete W]

Everything I read and was told said to go "0" tiller for 3 under. Today I was talking to Marc, at Chek-Mate, {Cujo} and this subject came up.
 He asked how I set the tiller on my ILF bows."0" of course.
 I just went downstairs and  shot a bow at "0" tiller, then changed it to 3/8" positive.
 Much quieter!!
 Thanks Marc.

 Pete

[buckster]

This is awesome feedback gentlemen, thanks SO much.

MARC, Good to hear you chime in here buddy.
I just ordered a LH Checkmate Hunter III from Chad recently, so be sure to work your tillering majic for me 3-under, and I requested a small grip for my girlie man hands.

   

[Don Baker]

Here is my take on even tiller for 3-under.

First off, the pivot point of the grip is below the center line of the bow and the 3 fingers pulling the string are also below the center line of the bow.

Those 2 factors are going to result in the string contacting the lower limb faster than the top limb which causes an imbalance in limb timing.

The main function of tiller is to help both limbs return to brace height at the same time, resulting in less noise and more of the limbs efficiency imparted to the arrow.

I would think that an even or negative tiller would be more beneficial as it would make the bottom limb weaker and therefore slower,allowing both limbs to return to brace at the same speed.

Don't know if that makes sense, but that is my take on it anyway.    

Don

[SERGIO VENNERI]

Alright Don ! Finally someone that knows a bit about geometry and physics  The more positive tiller theory does not hold water ! And I don't mean this as an insult to any Bowyer, i want to make that very clear !
         To keep it simple just take any length of bendable wood  and place its center against your knee with your hands at each end and try and bend it , if all things are equal dimensionally the wood should bend at the center , are we all agreed on that?? Then move the wood off center against your knee and again bend it , voila, the wood bends more on the longer side, so to make it bend equally you have to weaken the shorter limb.This is actually called the" static balance" of the bow. The actual tiller is a moving ( dynamic )  and called the " dynamic tiller ".
       As  Jim alludes to, when he tillers more positive " sometimes you might have to make some adjustments to the nock point",you shouldn't have to.
         When I switched to 3 under in the 80's , i was shooting Silvertips and Paul recommended i send them back for rebalancing. it just happened i was going out west for a vacation , so i brought my "
'Tips and visited Paul and we rebalanced to "o", by weakening the lower limb.The bows were instantly quieter. JMHO.

[CUJO]

The best way to see is try an ILF with adjustable tiller , try it both ways. My money will be on the more pos tiller..

[SERGIO VENNERI]

Marc;
        I agree that an ilf Bow would be a good test , as long as it was done with high speed photography to show the dynamic balance of the limbs in recovery, this would also eliminate any bias or placebo effect. Jack howard , Earl Hoyt and others have already done this and even recommend 1/8 negative balance on short recurves.My money is still on buying bows with negative tiller. by the way Marc ,i do like the looks of your Bows !

[larryh]

if the archer is pulling with equal pressure on all three fingers the lower limb would have to be stiffer to keep the limbs timed.
most people have less pressure on the third finger and are in fact pulling just about the same as a standard pull so even or slight positive tiller works for a lot of three finger under shooters.
black widow is tillering on the assumption that the archer ordering the bow is pulling equally with all three fingers.

[Txnrog]

So does it change if your primary pressure point is further down the string? I shoot 3 under, and most of the weight is on my middle finger, with a little weight on my ring finger, and very little weight on my index .. . as evidenced by the nifty calluses I am developing.

I am having a bow built currently, and curious what I should be looking for in a tiller. I recently bought a trees shadowhawk that shoots good for me, but we had to raise the nock point, and it has a very definate 'twang' in my hands.

[Jim Neaves]

With all due respect the pivot point is above center line!

[George Vernon]

I shoot 3 under and have been able to get good flight and low noise out of bows originally made for split.  It seems to me the 3 under shooter is moving the 'center' of the pulling force down the string versus where the center would be if shooting split.  As a result, the upper limb should be worked less to get the same draw length.  Hence a lower tiller, perhaps zero, would be in order.  Make sense?

[Morning Star]

I pulled up this thread doing some research as I have recently switched to 3 under.  I shoot a couple Widows tillered for split. I ended up having a 5/8 nock point and noisey bows when shooting 3 under.  I talked to Roger at Widow today and asked him about the tiller.  He advised they will tiller the bows evenly for 3 under and it should fix both the noise and high nock points.