Hi guys,
Just finished making my second bow (not counting the half dozen board bows that did not survive my tillering before it). It has a few issues, but I've shot about 100 arrows through it and learned a great deal more about tillering and bow design, as usual mostly through hindsight.
Its a swamp bloodwood, 65" NTN and 40 lb at 29". Limb width is 1.5". I have made it for a friend of mine who is interested in archery, and I thought 40 lb would be a good starting weight for him. It was also a good excuse to experiment with building in an arrow shelf, and it's the first time I've ever made a leather handle. I also experimented with heat treating the belly, which helped a little but its a very dense wood, so I'm not sure how much good its actually done.
The upper limb has taken more set than the lower, the lower is at 1 1/4" and the upper at 2". I can see (with hindsight) that the upper is bending a little too much just out of the fades, and not quite enough at about 10-12 inches out. I found that one hard to see at the time, as the limb has a natural lump right at the end of the fade, and another one just after the part where it's not bending enough. That second lump may also account for some of the set difference between the two limbs? I'm not sure. That lump is around where I started to taper the limb too.
Also, for both limbs I can see they have both taken some set at the exact point that I made the limbs start to taper towards the tip. In the future with this wood, I think a better design will be to make it full width along its length except the handle and last 6 inches of both limbs, which will be rigid. I also don't think 1.5" limb width was quite enough for this bow, and I should have gone for 1 3/4. And I think 65" NTN was maybe too short for a 29" draw. And I need to make the leather handle neater in the future.
But, I'll chalk all that up to experience and improve on it next time.
The bow is great fun to shoot! Its obviously not very powerful, but it is VERY accurate. Once I account for drop, that is. It lacks the kick of my first bow which is a 55lb, and has a little more hand shock than I'd expect for its weight, but it does the job and I hope it lasts him a while and, you know, doesn't explode in his face