Length/width?

[DC]

I tried my edge grained yew (http://www.primitivearcher.com/smf/index.php/topic,63436.0.html) in my machine the other day and it's lost about 10 fps. I'm assuming this is due to set so I'm making another. This one is 1/4" wider and a couple of inches longer. I'm hoping this extra wood will hold off some set. This got me wondering, how much do you have to lengthen/widen a bow to make a noticeable difference? I realise this is hard to answer but will an inch longer make a small, medium or large difference? Back to the edge grained bow. If you were trying to do what I am doing(reproducing a bow that won't lose 10 fps after a few hundred shots) how much bigger would you make it? length or width?

[Selfbowman]

Can't really say D.C. I have been moving mass around in the limbs of 67-69 in. Osage bows for about three years now. Trying to eliminate set. The closest to no set has been a pyramid design. I see no set bows of other design all the time though. It depends on how good at tiller you got  that day. I think we all have a bad tiller day once in a while. Or once in a while we have a good tiller day! Arvin

[Del the cat]

Now it's settled down, strap it straight and heat treat the belly maybe and have another look at the tiller.
My fave bow got a bit tired, I refreshed it that way and it better than before, the tiller had definitely shifted over a few of years.
Del

[Badger]

    Most of the time when they loose weight and performance over time it is because they gained back some moisture or they were not sufficiently exercised during the tillering stages.  I go strictly by mass weight which is controlled by width. Zero set almost never happens. I built one yesterday 73" long and 1" wide. It shows only 1/2" set after unstringing but I did loose 3# between 25" and 28". The first pull to 28" will read 52# and the second pull will read 50# 3rd pull 49# and this is where it stays. Rest it for 10 min and the same thing happens.

[DC]

Now it's settled down, strap it straight and heat treat the belly maybe and have another look at the tiller.
My fave bow got a bit tired, I refreshed it that way and it better than before, the tiller had definitely shifted over a few of years.
Del

It's got a maple backing. I'd be afraid to heat it

[DC]

So, could losing 10fps after a few hundred shots be considered "normal"?

[Badger]

  It would be normal if the bow was extra dry and then was allowed to stabilize at a higher MC, I have a feeling it lost that speed long before a few hundred shots. If you tiller a bow out at the same MC you will be shooting it at and have exercised it properly during tillering they normally won't change at all. It is pretty normal for a bow to pull slightly higher on the first pull then drop slightly after that but much better when the first pull is the same as the second, very good sign.