Tillering, + vs -

[skeaterbait]

I have heard that a bit of negative tiller is what you want for three under shooters. What does a positive tiller gain?

[Bowjunkie]

First of all, two bows, perfectly tillered/balanced at full draw for the same shooter, shooting them both the exact same way could EASILY show different tiller measurements at brace. Right? We could change just one variable of many, like location of bow center, and it would totally blow the theory you heard out of the water.

If someone understands these things, I don't know why they would make such an overly simplified, generalized statement. And if they don't understand, they have no business giving tiller advice, imo.

Secondly, there's so much directly opposing advice offered regarding tiller, it makes you wonder who, if anyone, should be believed. I've found the majority of the advice I've seen offered over the years, some published in books by respected bowyers and archers, to lack objectivity, adequately descriptive reasoning, and/or oppose my own findings.

I don't blindly agree with anyone in regard to this, never did, and prefer detailed, reasoned explanations by anyone offering their 'facts' over generalities like "a bit of negative tiller is what you want for three under shooters". My response to that person would be, "Really? Why?" and then, "Prove it, please". Not because I think they're incorrect necessarily, as much as I want to know if they've actually done the work, seen the proof, or are they just regurgitating what they've heard... perhaps from other unsubstantiated sources.

Heck, I've seen many folks directly contradict their own advice in the same paragraph. It CAN'T be both, so which is it? And others take the bulk of it as gospel. This tiller thing is so largely misunderstood. It's crazy... and kind of sad.

So don't believe everything you hear about tiller. In fact, you'd be better off not to believe any of it, and go forth with an objective mind to uncover the truths on your own.

[skeaterbait]

Can't argue with that line of thinking.  

[Wolftrail]

Thats a good reasoning Junkie.

[Jackpine Boyz]

Agreed, I final tiller based on the bow owner drawing the way they plan to shoot and adjust. Tillering trees do not replicate how we hold the bow which is very variable.  I've shot split and 3 under.  But with all the variables some are even some are +/-.
If I have a choice, I keep the bottom limb the stronger of the 2 as I seem to stress mine a bit more and it weakens over time.

[Bowjunkie]

"Tillering trees do not replicate how we hold the bow."

That's another generalization.

They certainly can replicate our holds/fulcrums. But most don't even try.

Not all tillering trees are created equal. Some are infinitely more variable than others, and come much closer to replicating various archers' holds than their counterparts.

Unfortunately, the common untruth that they can't, is often used as an excuse for mediocrity or a perceived ease of production. not.

It baffles me how the very folks who go to such great lengths and effort to coax bows from standing trees, choose to try to make things easy for themselves when it comes to, arguably, the most important part.

But I digress, from what I've seen, the stronger you keep a bottom limb, relative to dynamic balance, the more it will weaken with use. Hey, just flip the bow over, right? and oh-oh... gotta repeat.. and oh-oh... gotta repeat.. Things that make you go... hmmmmm.

[C. Johnson]

I'm certainly no expert, but I just try to get both limbs bending equally.  As close as possible.  I fully acknowledge that I have a lot to learn on the subject, but it seems to not be as critical as some folks would have me believe.

Honestly, I get it close and my bows seem to shoot just fine.  I tiller mine to be balanced on center.  Whichever limb is slightly stronger, becomes the lower limb.  

I've made myself nuts with this.  I've had bows come off the form with identical measurements on both limbs at brace height only to be off by an inch or more at full draw.  And vice versa.

Now, if the measurements at brace height are within .250" of each other as measured at four points on each limb and at full draw, I call it good.

[skeaterbait]

I guess my bow making/tillering could be summed up as the neanderthal method... "arrow hit spot? Kronk happy"

[Todd Cook]

I believe it is as critical as some would want you to believe. Ye, you can get the tiller out of whack and the bow can be shot fairly well. For a while. It took me a while to figure out that if the limbs are fighting each other(bad tiller) the bow won't hold up. I made several selfbows that started out shooting good, but over time and several shots the limb(usually the bottom) would start to take set. The limbs need to go through the draw cycle together, in relation to how you hold the bow. If they do, assuming decent design, the bow can last a long time.

[C. Johnson]

I should add that I only build glass bows.  I'm sure it's very critical on an all wood bow.

[Mo_coon-catcher]

I try to keep tillering simple. I hang the bow from the scale by a rope loop that I feed through itself and clip on. Early in the tiller on the long string I pull from center of the string so the handle stays level as I work it back . Once I have it braced I clip the pull rope from where the middle finger would be pulling from so that the pull force would be the center of your pull force as if you were using 3 fingers. Hooked up this way the bow will tip towards the top limb, when as you come to full draw the handle section will level out and the limb tips should end up at an even point compared to each other and the handle. When that happens the bow almost always is a smooth and quiet shooter.

Kyle

[J.F. Miller]

Originally posted by Bowjunkie:
First of all, two bows, perfectly tillered/balanced at full draw for the same shooter, shooting them both the exact same way could EASILY show different tiller measurements at brace. Right? We could change just one variable of many, like location of bow center, and it would totally blow the theory you heard out of the water.

If someone understands these things, I don't know why they would make such an overly simplified, generalized statement. And if they don't understand, they have no business giving tiller advice, imo.

Secondly, there's so much directly opposing advice offered regarding tiller, it makes you wonder who, if anyone, should be believed. I've found the majority of the advice I've seen offered over the years, some published in books by respected bowyers and archers, to lack objectivity, adequately descriptive reasoning, and/or oppose my own findings.

I don't blindly agree with anyone in regard to this, never did, and prefer detailed, reasoned explanations by anyone offering their 'facts' over generalities like "a bit of negative tiller is what you want for three under shooters". My response to that person would be, "Really? Why?" and then, "Prove it, please". Not because I think they're incorrect necessarily, as much as I want to know if they've actually done the work, seen the proof, or are they just regurgitating what they've heard... perhaps from other unsubstantiated sources.

Heck, I've seen many folks directly contradict their own advice in the same paragraph. It CAN'T be both, so which is it? And others take the bulk of it as gospel. This tiller thing is so largely misunderstood. It's crazy... and kind of sad.

So don't believe everything you hear about tiller. In fact, you'd be better off not to believe any of it, and go forth with an objective mind to uncover the truths on your own.

EXACTLY. well put, Bowjunkie

[Roy from Pa]

I tiller my bows for equal limb timing, not by inducing a certain predetermined positive or negative tiller.

I let the equal limb timing determine what the tiller will be.

[Al Dean]

I tiller mine, glass bows, by where I have to put the nock point to shoot properly and quietly.  I like a 7/16 nock point.  So when I shoot a bow during build and say it requires a 5/8 nock point to shoot properly.  I will sand bottom limb a bit to take some of the positive tiller out until I get nock point to where I want.  May take several tries.  Of course my preferred nock point may be different than yours.  Tiller ends up where it does, +-, for that particular bow.

[skeaterbait]

So all in all it sounds like the rigid science of tillering comes down to a one rock solid rule.

You definitely have to have positive tiller, unless negative or even is better.

[Roy from Pa]

You definitely have to have positive tiller.

NO

unless negative or even is better.

Maybe

 

[Roy from Pa]

Tillering for equal limb timing for split finger.

The pull rope follows the black line on the wall, which means both limbs are bending in sync.

 

Tillering for equal limb timing for 3 under.

 

[Wolftrail]

I try to make it look good in the mirror at full draw.  Other than that I do not shoot my wood bows 3 under, it places more stress on the bottom limb.  Shooting 3 under on the glass bows works better for me.

[Jackpine Boyz]

Bowjunkie,
how is your tiller tree set up?  i have the typical pulley with a hook attached to the bow string that i put at center or fix with string nocks slightly below for some variation.  since people typically draw with 3 fingers and various tension on each finger, i see variations from shooter to shooter even when using both 3 under or split.  i personally don't have much variation when i shoot split vs 3 under with my self bows, but i've seen some people with very notable differences.  the inherent differences potentially present in various self bows such as knots and holes further effect tiller.  i know several proffesional bowyers in wi with glass bows that typically don't worry about slight variations but they also see certain shooters requiring +/- tiller adjustments.  Fixed crawl is a whole other tillering challenge as well.  ILF bows also have adjustable limbs for various styles in addition to tuning. I wasn't expecting to be attacked for agreeing with you, but if there is a better way to build a bow, i would to know it. Having final tillering done after the bow's owner runs some arrows through it seems to be a simple and effective way to me, i wasn't trying to be lazy.

[PEARL DRUMS]

In the world of natural bows negative and positive means virtually nothing. Bow hand balance is everything. Glass bows are perfectly symmetrical out of the oven and have a more predetermined tiller. Natural bows can have, for example, reflex off the bottom fade and deflex off the top fade creating a negative measurement. Yet have perfect balance in the bow hand. If you were to take this hypothetical bow and make it appear proper to your eye you would effectively toss it out of balance and make a loud, uncomfortable bow.