Have a question Guys about tillering

[Roy from Pa]

I didn't know Boston had a baseball team:) LOL

I don't care for making glass bows either, but I will say the guys on here make some nice glass bows.  


But Wood is Good Stuff....

And most of what Art tells me goes in one ear and out the other, I only remember the good stuff he says:) I write that down so I don't fergetit:)

[SEMO_HUNTER]

I guess I misunderstood how the experiment would go? If the string is stationary at the point where it contacts the string, then it should pull to the heavier side. If it's allowed to slide on the string then it should "slide" to the weaker side. That's just how I visioned it, but I'm probably wrong.

This is too much like thinking and it makes my head hurt. Them damn Yankees are supposed to be the smart ones anyway.      

[Roy from Pa]

Trust me Elmo, the rope drifts to the strong side, dat's all ya gotta write down:)

[George Tsoukalas]

I am certainly happy to be enlightned, Art. Believe me I can use all that I an get.
"The more efficient the equipment the more efficient the kill. That's my only mentality."
Me too. My rant wasn't about efficiency, for the record.
But, Art, there is no need to put baseball down.    Jawge

[George Tsoukalas]

I figured y'all would light up your torches on me.
That's ok, Art. I like ribbing. It's what we men do.  Every now and then I gotta do a rant so you guys know I'm still around.
I like flower gardening and ballroom dancing. YOu can imagine the ribbing I take from my brothers. LOL.
"Trust me Elmo, the rope drifts to the strong side, dat's all ya gotta write down:)"
That's ok, Semo. Took me 10 years to figure that one out. Boston, sure does, Roy. I hear they won the World Series 2004 and 2007. I thought I'd never even see one in my life. I love baseball almost as much as primitive archery. It's close.  
Jawge

[SEMO_HUNTER]

Originally posted by Art B:
Don't even own a glass bow George.

The more efficient the equipment the more efficient the kill. That's my only mentality.

+1 on that Art, I've got one glass bow a Bear Grizzly and I'll keep it forever cause it was passed down to me by my uncle. When it's time I may pass it down to my oldest nephew.

I'm all about making the most efficient bow I can, that's one reason why I stepped it up a notch with the bamboo backing. I'm rather pleased so far and a heck of alot more zip.
I want to reach a point where I hunt with my own bows and nothing else, just like some of you all do.  

[Roy from Pa]

I also have 1 glass bow. A Bear Victor Viking Takedown which I bought in 1970, maybe 71, could be 72, I forget now:) Took a slew of deer with it and it still shoots great, but darn it's about 5 pounds heavier than any of my BBO Bow's.

[SEMO_HUNTER]

That's pretty Roybert, I'd just keep it hung up somewhere for looking at.

[Stiks-n-Strings]

I'll have to say Jawge hit it on the head with the glass mentality. Don't misunderstand me. I love all bows without wheels and shoot both all wood and glass but I only build wood bows. When I first started I had glass bow mentality and ruined some good staves trying to make them look like what I thought they should look like. Glass bow building and wood bow building are two different playgrounds.

Once i figured that out I started building some shooters. And for the record Jawge I like a little baseball myself bud,    

Alot of good input here on this subject and I always learn something so thanks for that.

I tiller my bows like Scifres on a fulcrum, the same Dean Torges does it. I do my tweaking in the hand while shooting in. But what I do works for me.

Stiks

[Roy from Pa]

I have seen these Ellipse pictures before but never tried it, how's it look?


 

[SEMO_HUNTER]

Looks pretty good Roy, maybe just a little more work on left side mid limb. It looks like it's not bending quite as much as the right limb.
Overall not bad for a Yankee that has a bird dog that points bullfrogs.  

[Art B]

What you're seeing Chris is a bow being tillered for a split finger draw. That left/lower limb will come round when draw by hand.

You would be correct if he were tillering for three under where the bow's center and drawing forces are more centered...Art

[NYArrow]

I can't quite wrap my mind around Art's statement. In my mind it seem three under would bring the limb around even more than split finger. I always assumed split was a more centralized form of shooting and 3 under is where the stronger bottom limb comes into play. I'm not saying he is wrong I just have trouble picturing it. Any help for a dummy like me?

[Roy from Pa]

Don't worry, Art can't either:)

[Art B]

Your thinking is reversed NYArrow. Three under is more apt to evenly strain both limbs where as split fingers adds extra strain to the lower limb causing the need for a stronger lower limb.

But all this is somewhat overstated because everybody grips a bow differently, no matter what method of draw they use. This positive/even tiller/stronger limb debate can be done away with, IMO, simply by tillering for even limb strain at full draw.

When you hear someone recommend a 1/4" positive tiller for split fingers and an even tiller for three under, what you're really getting is a one-size fits-all approach to cover the vast majority. In reality, if you tiller for even limb strain at full draw, you'll find your true tiller is much closer than the above approach........Art

[Bowjunkie]

Ok, after some real life testing, I edited this post because I was wrong in a part of my logic. But things still may not be what you think they are, or have been led to believe, so read on....

I respectfully disagree, Art. I concur with what NYArrow said. "In my mind it seem three under would bring the limb around even more than split finger. I always assumed split was a more centralized form of shooting and 3 under is where the stronger bottom limb comes into play."

Here's my thinking. The string is effectively divided into two parts of set length once the string hand is placed and begins pulling. It may help visualize this if we think of the bottom tip(left tip in Roy's pictures) as point A, the top tip(right tip) as point B, and the hook(or fingers) on the string as point C.

     

Sliding the string hand 'C' down toward the bottom tip 'A' shortens the distance A-C and lengthens B-C. These work basically as levers, and longer levers complete more work with the same force. Now, we're still drawing 'C' to anchor regardless, so since A-C is now a shorter lever, it is overpowered by side 'B' and tips that way. Hence, limb 'A' needs to be stronger to resist it and again establish balance.

In order for my example to act right, balanced at full draw, the left limb needs to be stronger. Stronger because of the force added to the bottom limb, not the top.

So, three under strains the bottom limb more than split, calling for a stronger bottom limb, and split finger strains the top more calling for a stronger top limb. Now, by stronger, I mean 'in relation to' being tillered the other way, not necessarily stronger as viewed at brace when compared to the other limb... but some truths are apparent there as well.

Art, you said, "When you hear someone recommend a 1/4" positive tiller for split fingers and an even tiller for three under, what you're really getting is a one-size fits-all approach to cover the vast majority."

I'd say what you're getting is poor advice... since the opposite results in better-tillered bows in each regard.

Better advice is; To tiller the bow so that the limbs see equal strain at full draw with the fulcrum point under the bow hand exactly where the shooter prefers it in the grip, and the fulcrum point on the string facilitating his grip there(three under, split, etc)... while disregarding advised arbitrary 'tiller measurements', such as 1/8 or 1/4 positive, etc.

A bow tillered evenly, with its center at the center of the handle, and pulled by the center of the string, will show both limbs flexing equally. Yep, hard to dispute that.

If the same bow, tillered evenly, is pulled from above string center, the top limb comes around sooner, bringing the arrow nock with it, and must be strengthened so that it won't. The converse is true as well.

It's definitely opposite of the advice often given.

[red hill]

Geez, bowjunkie, what engineering school you teach at?    :D   (That's South Arkansas speak for, "High tech description.")
Seriously, your illustration and explanation is quite understandable.
Keep up the explanations, guys, I'm learning tons.
Stan

[Roy from Pa]

Well now I am confused. Art from WV says this, and Bowjunkie from Pa says this.

But which way will the pull rope slide towards, to the weak limb or strong limb? Dat's all I wanna know.  

And the other thing I wanna know is, should I pull the bow from the center of the handle on the tree, or should I pull it from the top of the handle, which is closer to where I will pull it when shooting it .

[SEMO_HUNTER]

I sold my compound and started making my own trad bows for myself in order to get away from "Complicated" and gravitate toward "Simple".......so much for simple.

Maybe this is effectively what I'm doing when I make the bottom limb a more positive tiller than the top limb to shoot well with my 2 fingers under style release? And didn't even realize it?
Or did I.   :rolleyes:

[Rattus58]

Well not having done any of this yet, I'd say its a little offset to the right... or am I looking at it wrong?

Aloha...