Limb taper

[DC]

Is limb taper always linear? Like .070 per 6" all the way out the limb or is there a style/design where it changes? I'm trying to arrive at some ground rules for myself when I'm tillering R/D's. I'm thinking that eliptical tillering would have to have an increasing taper. The front profile would have some influence too, wouldn't it?

[willie]

Is limb taper always linear?

not at all. consider the thickness profile of a molly or something with a siyah

[Del the cat]

It depends.
On a bow with no width taper (or very little) the perfect theoretical taper is some fancy mathematical  curve which increases as you reach the tip... but it pretty much sorts itself out if you do a linear taper rough out, allowing the tips to be a bit thick and work outwards on the tillering as the limbs come back... then taper last 6-10" or so into a graceful curve when you do the nocks.
On a bow with constant thickness (pyramid bow) the width taper is linear from full width to zero at the tip.
The difference is due to stiffness bing proportional to width, but proportional to the cube of the thickness.
There's probably an equation for the thisness taper somewhere... but it is probably of no real practical use unless you are making a bow limb on an NC milling machine
Del

[Stick Bender]

Most guys I know making Tri-lam D/R bows are running a linear tapear in conjunction with tip wedges Bayu Ben that used to come around hear I believe he ran a .006 pre taper the taper depends on front view like Del said ,I personally run a pre linear taper on all my wood bows and touch up during tiller ,with lam bows you can get very close to tiller with it ,putting less stress on the wood in my opinion & time to tiller , when you figure out the pre taper for your given design it's easy to build the next one , so does every design have a linear taper no ,do most bow designs have it yes , just my thoughts , but front view can also be altered for taper effect some guys leave the outer third wide and side tiller for effect & mass !