REALLY tiller on the edges?

[Del the cat]

Yes, dead straight taper... all limbs same length ... no fiddle factors.
Simple is good with experiments. Fewest possible number of variables.
Del

[George Tsoukalas]

Del, it would seem to me that the piece of plastic you triangled and bent will bend elliptically with the wider portions bending  very little. Yes?

If so then that is precisely want you do not want in a bow because the outer portions of the limb, if they bend more, will yield  more set.

Rather, the near handle, wider wood needs to bend more resulting in a more rounded circular tiller. Cuts down on set.

How you get there does not matter. Tiller edges, belly or a combination.

IMHO.

Jawge

[Jim Davis]

I encourage lots of youse guys to make a test piece like this, clamp the wide end and and push on the pointy end. Even for those of us who have been making bows for years, it will be an eye-opener bordering on a jaw-dropper for those who have not tried this.

Jim Davis (who only makes "pyramid bows" because of this bending behavior.)

[PatM]

Remember it is a string gripped in the  center that bends the limb, not a force pushing straight down on the tip.

[mikekeswick]

Push diagonally then!
Asharrow is dead right.
It's all logic as Badger said above.
The experiment should be between two actual bows. One a pyramid taper and one with no width taper until say 8 inches from the tips. Tiller them both to take the same overall amount of set and just look at them at full draw.
Badger I agree that the more working limb there is the more the bow 'buckles' when the string hits home. This is another reason why Turkish hornbows are so fast.
Simple. 

[Lucasade]

I can't add anything to this discussion, but reading all you experts discussing tillering from first principles is really helpful for the likes of me who as yet know essentially squat about it but like to know the 'why' as well as the 'how' - so thank you!

[Pappy]

Usually only do it when I am getting really close to what I want, little harder to take to much off the edge so for fine tuning and final tiller I use it some. Interesting conversation going on.
   Pappy

[Springbuck]

I'm not sure where you got the Info on side tillering pyramid bows, I've built a ton of them and don't think I've ever side tillered one, I start with an even thickness but buy the time I'm done tillering there's usually a silght thickness taper

I agree.  Mine end up with almost no taper in thickness, but the thing I like about pyramid bows is that I cut the fron profile out and then don't mess with it.  The very slight thickness taper sort of happens by default.  For instance, I put maybe a slight trapezoid to the cross section, and smooth that in and I'm done.

If all your previous bows were simply tapered side to side in straight lines, like a long, skinny triangle, there shouldn't be room for much front to back taper.  The regular bend of the consistent side taper isn't just good for bows, it is essentially an engineering principle.  So, I'm puzzled, a little.

[bow101]

My bow is hard maple.  It's a Christmas gift and, being that we're well into Dec., there's no way I'm gonna commit it to an experiment.     Hopefully, it'll be "harvesting" forest rats next year.

It'll be interesting to see Del's results!!

Lately this is all I make Maple Lam bows with a 20" power lam.  About 1 3/4"  fade down to about 3/8" - - - 1/2" tips.  I do not touch the bellys nor are the lams tapered.   I just taper them down, have to be careful where you start because of limb twist.
My bows take about 1" -  1 1/2" of set, and they are all stressed to over 29".  Maple is very forgiving the wood fibers stretch more than most woods. 

[Knoll]

Thanks, 101, for the post.
Fyi, I busted the $!*& bow shortly after getting to full brace.   
I've got a couple maple bows and do like 'em.  But haven't tried the lam route yet.

[Dvshunter]

Alright mike. You have suffered enough. Come by the shop and I'll get you fixed up on a good stave to make a suitable bow from

[Knoll]

Alright mike. You have suffered enough. Come by the shop and I'll get you fixed up on a good stave to make a suitable bow from