Thursday, 12 July 2012

Hornbeam Looking Better

video
It's recovered to almost 40# at 28" with no overall reflex or deflex.
The lower limb still has rather a kink to it and I might ease off the upper limb a hint more.
The kink is where the knot and natural bend was and I don't want to try too hard to straighten it and risk fracturing it, maybe I'll fill that knot which will just stiffen it a tad.
It's looking much better  now and shoots with a decent punch.
The brace height is still low, a shorter proper string and a whisker off the right limb and I'll be able to shoot it in with 50 arrows or so and see how it settles down. I'm much happier with it now.
Hmmm! I've just looked at the previous video again and I'm not convinced it's actually looking much 'better' I think it looks slightly less symetrical at full draw, but then it should, as it isn't symetrical at brace!
The right limb now looks a bit less hinged. this all illustrates how subjective it is. The only real truth will come from the chronometer, although I didn't measure the speed before the last work.
Interestingly there are plenty of cases of bows being reduced substantially in draw weight, but shooting faster because the tiller has been improved.
Anyhow I'll post some still shots when I've done the final tweaking and got a decent string on it.
Update:-
I've thinned the outer third of the upper limb and scraped it a bit nearer the grip too, I put it on the tiller and it read 30# !, seems a bit odd, but after a while I twigged. It slowly recovers when unstrung to have a hint of reflex, but the draw weight drops off once strung for a while and the reflex disappears. This recoverable rreflex is 'string follow' as opposed to 'set' which is permanent, a minor distinction I s'pose.
It also illustrates how draw weights can sometimes be missleading.
When it's all finished I'll take the draw weight after I've shot a dozen arrow from it, probably find it is about 30#, but hopefully a fast 30 pounder.
Update2:-
I've made the string and it shoots nicely, after 6 shots it weighed in at 37# at 28". After more shots and getting my son to take some video of me shooting into the garage (you can see I don't have much room!) I took the string off. With the tips of the bow held up against the door frame I could slip one finger between the door frame and the grip (belly side) so it's followed the string a bit, but I dare say that after an hour or so it will be back about straight.

2 comments:

  1. That is coming along nicely! I is a challenging piece of wood, isn't it? :)
    Good work! What is the wood like to the touch and to work with? Seems quite bright to look at.

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  2. It's quite nice to work with, not as hard as Ash, not quite so smooth and easy as Hazel. After the heat treatment I could really feel it was crisper to work.
    With hind sight I'd should probably used heat to get it more symetrical earlier, but it's turned out ok and shows that the wood behaves reasonably. I'd rather have some set and string follow than a broken bow any day.
    Hard to say if it performs better than hazel. I'll shoot it through the chrono some time.
    I think Hazel probably wins on the grounds of it's easier to find a straight bit!

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