Thursday, 7 November 2013

Tiller Improvements

I've bought a pulley so that I'll have 2:1 advantage when pulling on the tiller rope by hand. This will allow me to dynamically flex the warbow. The pulley was only about £4 including postage, it's stainless steel and looked a tad flimsy when it arrived, however close inspection convinced me it was up to the job. Heavier duty ones which are actually load rated are more expensive, but 150# or so on the tiller isn't a huge load. After all it's rated as suitable for boat rigging and washing lines, and the lower pulley is just a washing line one from a hardware shop. Here's a vid showing how it moves, most of the bend is still in the inner 1/3 and the right limb looks stiffer, so I may swap the bow round.
The video shows how it is this morning (Thursday) hopefully by the end of the weekend it will be getting V close to full draw).
A worrying development:-
There are a few fine longitudinal cracks in the belly, they've been there for ages from the seasoning, probably radiating out from the centre of the log. I was hoping they would disappear as I worked down the stave.
I've done some work on the outer thirds and found it looks better reversed on the tiller. I re-strung it and gave it a pull, I could feel a pinch under my bow hand and one of those cracks has developed a crack across the grain to another fine longitudinal crack, like a 'H', it's only a fine sliver of wood bulging up but not nice....
I flooded it with low viscosity superglue, unstrung it and bound it up tight.
I feel it will be ok as the grip section is still pretty heavy and most of the extra flexing needed to reach full draw will be from the outer bow limbs. Worst case, it will keep pinching and raise a splinter in which case I'll rasp out a section and lay in some fresh wood. At least it's on the belly.
Never easy working with a stave, I'll press on... fingers crossed.
I've taken the binding off now and I can't even see where it was...I'm not counting my chickens, and I'm not going to flex it until I've reduced the outer limbs a bit more.
The actual pinch was sort of on the side of the belly which isn't quite so worrying. If you take the back as 12 o'clock and the belly as 6 o'clock. The pinch was between two cracks which were at about 4 and 5 o'clock.
Dunno if that makes sense. Anyhow, I'm feeling calmer again...whew.

1 comment:

  1. Eeeeeeeek!!!!! Panties at 90% capacity here Del......and I don't mean at the front !!!