Ozbow

Hi all
Just finished up this lil beauty using a piece of yew i thought would be no good at all due to knots. Granted this is a kids bow but I'm still suprised that it didn't break considering the back is not at all flat and quite bumpy and wavey and consists of a mixture of heart wood and sap wood and some bad knots that go right through from back to belly. The bow is 40" tip to tip and is drawing about 10#@17"

cmoore,

I think you have done a good job on that little bow. As usual, I did a analysis of your tillering job which is actually pretty good even though my picture does not look like it is. I have rotated your picture so that your tiller is vertical.

The reason for it looking wrong is that you have simply placed it on the tiller unevenly which makes the right limb bulge more than the left. That can be ascertained by measuring the length of the strings from each tip back to the tiller. The string line C-D is longer than the string ling C-E which means that it isn't centred. The green line above the bow's back shows that the right hand side of the riser area is higher than the left side. So, if you had positioned it a bit differently, it would have shown you tiller job to better effect.

Don't be surprised that your little bow did not blow. The stressors on a small bow are just as great as on a full sized adult bow from a mechanical perspective. I have long held a doubtful suspicion about the integrity of Yew being entirely dependent upon the integrity of the back surface and especially the sapwood.

In TBB Vol. 2 I think it was, Paul Comstock made a Yew bow for his teenaged daughter which had violated back rings and no sapwood at all and he reported that it shot fine. I have one here with me with seriously violayed sapwood growth rings which is quite sound and shoots fine.

Good Job cmoore ! Sure a Bow like yours will look better with a lovely thin line of Sapwood for a Back but you have just proved that is all it does is look better. Besides it has character, and it shoots Arrows, what more could you want !

regards Jacko