Friday, 18 May 2012

Nocks, Tweaks and Test Shots

 
On the last full draw pic, I had a sneaking suspicion that the left limb looked longer, so now I've got the nocks on I remeasured the centre and it was about a quarter of an inch out. Where I'd adjusted the string it had also moved the tape marking the point on the string where it should be drawn from. These errors were small and the minor work I've done near the tips makes the tiller look even better now.
Since these pics were taken I've taken a whisker off the right limb by that knot just right of the grip as it looks a tad stiff there and the right limb looks a little stiffer than the left. These are real subtleties now, as when an ellipse is drawn on it in 'Paint' it looks very good. I'm now trying hard not to tinker with it any more.
At the primitive meet last weekend I saw a bow with really slim nocks, they were antler which is much harder than horn, but I though I'd go for a slimmer style of nock, narrower than my normal and with the string groove limited to the back of the bow rather than extending round the sides. The white Waterbuffalo horn is translucent and you can see the grain of the heartwood through it at the sides.
When I first started doing horn nocks I didn't much like it and found it very time consuming. Now I've become more adept and honed my technique I rather enjoy it as they have a sculptural quality and can have some individuality. These days I drill the horn, shape the tip and glue the horn onto the bow before I do any shaping of the horn. With the horn glued in place it's much easier to shape and the bow provides a long handle to guide it carefully under the bandsaw to rough out the shape of the nock, this saves a good deal of laborious rasping. It's a bit nerve wracking the first time as a bandsaw can runaway from you if you blink! Of course a good deal of care is required to avoid rasping the bow limb and careful holding of the bow is essential. I use a piece of old woollen carpet draped over the vice jaws which I have slightly open to rest the bow in or to lightly clamp it. The other end of the bow rests on my trusty cushion and sometimes my plastic tool cady is rested on top of it to stop it waggling about.
You can see the heartwood is fairly pale, it will be a bit darker when the Danish oil is on it and the whole bow will have some nice honey tones.
I've really just got the string to make, the arrow plate, some finishing and shooting in before it's finished. This bow won't have a leather grip as it's fairly large and comfortable to hold.
Test shots:-
Wow, it certainly slams home the arrows. I've had a stiff neck for a few weeks and shooting the 5/16" 100grain point arrows was jarring the back of my neck. It was grouping fairly well. I tried a 125grain point, not much different.
I then went for the 11/32" 100 grain ones, smooth as silk, tighter group, hitting the scrap of paper that was on the target with 2 out of 4 arrows.
Weather permitting I'll take it to the club tomorrow and get it shot in. It'll be interesting to shoot it through the chrono' as it seems quick to me. Looks handsome too in an understated way.

2 comments:

  1. I really like you paint-images with the circles to show the tiller.

    Is there a set of rules to figure out the centre and radius of the circle or is it just a matter of experience & trial and error?

    /Håkan

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  2. I just draw an elipse/circle and pull it around for a best fit (it takes several attempts). It needs to be viewed carefully to show any slight problems, but it will helps show up any big errors. I expect it to centre it on the vertical line of the tiller tree. On the previous full draw pics, I noticed the best fit was centred a bit left of centre, it's now more central.
    On one bow I made, I really tried for an arc of a circle so I centred an actual circle on the point where the string is being pulled to see how close I got.
    Some people go for a much flatter ellipse, but it depends on the style of the bow and personal preference. It doesn't work quite so well on bows with long stiff grips or heavily recurved tips. It's just an aid really and sometimes the eye can be deceived by the the heart sap boundary or big knots so it can help. The real test is a full draw shot with an arrow on the string.

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