Saturday, 2 July 2016

Boo Backed Yew done ... or is it?

The bow is looking really good and shoots very crisply.
I twisted the string up a bit to get the brace height right and thought it looked a tad off, the lower limb looks a little over stiff at brace. Generally the lower limb is tillered a little stiffer to allow for the asymmetry of the draw, but this seemed a bit too much.
I put it on the tiller and it looks lovely at full draw, so I won't panic and over react, I'll get it shot in and see if it settles at all, I'll also let the guy I'm making it for shoot it to see how he finds it.

It's not actually a problem, just me being hypercritical... I don't s'pose most archers would even notice. There are plenty of little tweaks I can do to adjust it here are some of the things I could do in no particular order:-
1. Ease off the lower limb a tad, (but I don't want to drop poundage).
2. Do a tiny heat bend on the lower limb to deflex it a hint  (but I don't want to drop poundage).
3. Heat treat the upper limb to stiffen it a tad.
4. Do a slight heat bend in the upper limb to remove deflex or add reflex.
5. Take an inch off the upper limb to stiffen it a tad.
6. Leave it alone and stop being obsessive!

Here's a couple of pics showing some of the interesting grain. It's worth noting the the billets were cut from wood which would have been marginal for a self bow due to bends and twist such that the sapwood would lie along the back of the bow. By careful sawing the wood is fine as billets for backing with another wood as it will all in compression and the grain direction isn't so important. Of course there is a risk of warping and such like, but it's all part of the fun. On one billet thre are signs of the central pith of the wood along the centre of the belly, but on the other limb there are signs of it along one edge. That lovely swirling grain in the left pic, is a handsome feature, but probably couldn't exist in a self bow.

I've just shot another 10 arrows and had another look... it's fine, I think it's just the unbraced shape showing. The two billets are not a perfect match even with the bit of heat bending I did in the early stages before glue up. After all, it's not supposed to be a laminated recurve made on a former! Anyhow I'll calm down, have a nice cup of tea and keep shooting it in over the course of the day.
It does shoot nicely and rings like a bell when given a good crisp loose from a full 28" draw, yet doesn't feel at all harsh. I've stuck 5 scraps of masking tape on the boss so I can spread the shots around.

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