Monday 2 July 2012

Flexing Hornbeam

The bow is begining to flex, it has 4" of natural reflex and it's taking about 45# on a long string to even get the limbs back to somewhere near straight.
The bow flipped on the tiller and the scale fell on the floor, it stopped working so I opened it up to find out what was wrong. The mechansim is self explanatory with a toothed rack engaging onto a cog to turn the indicator hand. The rack had slipped out of engagement. I used a G clamp to avoid it happening again.
The pic on the right shows how the bark is lifting cleanly off now.
I'm expecting to pull some of the reflex out during tillering, but maybe end up with an inch or two.
It's going to be difficult to get a good tiller and draw weight, the big danger is making it too weak and finding that when I get it braced the extra leverage of the short string gives me a 20# bow. The other extreme is that the stress is just too much with that big reflex and it explodes.
What I may have to do is keep an eye on the amount of set and if it is getting too much I may have to use heat to take out a little bit of the reflex.
Hopefully I can just turn it into a bow without any messing about.
Hmmm, I've done a bit more and I'm getting a bad feeling about it. If I draw it I feel I could just keep pulling it back until it blew, and yet I'd be expecting the draw weight to come up.
It hasn't taken any set yet (well maybe it's lost 1/2" of reflex) I also heard a slight 'tick' as I pulled it back... that is normally the death knell for a bow, but it could be the bark as a section near the grip had come loose.
That's a good thing as I'm trying to get some bend into the handle region. maybe I've bitten off more than I can chew?
Anyhow, a couple of days at work will stop me messing with it.

2 comments:

  1. Go slow. You'd be my hero of the day if you turned this one into abow. It doesn't look like one a bit yet. Well, maybe a tiny little, but that is mostly hopeful imagination from my part. I'll follow you trough this one with exitement. That bark will surely tick some more, don't get unnerved.

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  2. Yeah, maybe I'll manage it if I aim for 20# at 18" draw ;)

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