Friday 1 November 2013

Warbow Flexing

I've pulled the warbow back to about brace height on a long string. the scale is reading 140# at this point.
However it's deceptive when pulling on a long string. Once the bow is braced in that position the scale would be reading zero! If you plot a force draw curve for a bow, it goes from full weight at full draw to zero at brace height. So that 140# becomes stored energy in bracing the bow and it's hard to judge what it becomes as a real draw weight from a braced bow.
That's why it's important to get a short string on a bow as soon as it's safe to do so.
E.G. I took the 100# Elm warbow and put it up on the tiller with the same long string and winched it back until the tips had come back 6" (to about brace height). The scale read 55#, this gives me some sort of reference and implies I'm about on track with the big Yew bow.
Most of the flexing is on the inner third at the mo', but again, a short string changes the angles and leverage so I want to get to a low brace pretty soon.
I may put the Elm bow up on the tiller at 32" and draw round it to give me a reference curve... dunno
Update:- I had to make a tillering string out of the last of my Angel Majesty as the Dacron is like damn rubber at these weights.
Got it to a 2" brace now so I can see it has plenty of draw weight still.
I've ordered some Astro Flite... dunno what that's like, the vast proliferation of string types oft' referred to generically as 'Fastflite' leaves me stoatally* confused. The Astroflite is about half the price of Angel Majesty and twice the price of Dacron, so hopefully it should be ok.

* stoatally...
As in the old joke:-
What's the difference between a stoat and a weasel?
A weasel is weasilly distinguished whereas a stoat is stoatally different. :-)

3 comments:

  1. You're going to need a pet gorilla just to brace this brute!!

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  2. Good idea to compare it to the elm bow. I never took a done bow back on the long string.
    Make a video of he bracing, please...

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  3. Difficult to show it being braced as I'd be standing between the camera and the bow.
    I put the string on the right limb, slipped down a few inches from the nock. The left loop is in groove of the nock with the rope over it like in the picture. I then winch it back on the rope as in the pic to flex the bow and slide the loop over the right nock, which has a double groove. Then I let down the winch and it's strung. It's too strong to brace it by hand at the moment.
    More pics tomorrow, hopefiully I'll get it to maybe a 4" brace and be able to see a decent curve at a sensible draw weight.

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