Everything an amateur bowyer does to turn a log into a bow throughout the year.
Making bows, longbows and primitive bows with all the tips, tricks and problems.
Friday, 28 September 2012
Final Adjustments and Angst
The bow wasn't really comfortable in the hand , so i extended the grip down a bit towards the lower limb keeping a careful eye on the thickness of the limb. I couldn't narrow it down into the thin section.
it feels more comfortable now and the hand isn't pushing the arrow up above the arrow plate.
It shoots sweeter now and the finishing has dropped a pound or two so it now draws about 48# at 28" and I pulled it back to 29" where it showed 50#. (I normally test bows to 1" overdraw)
The second pic shows the nice figure on the belly of the top limb.
I was wiping on another coat of Danish Oil when I noticed a couple of tiny compression marks on the belly on the upper limb. I wasn't amused as they had just appeared out of the blue. This is what caused my angst. Should I just leave well alone or fiddle with it?
Chrysals aren't fatal, they are just ugly! I've had bows with the odd few chrysals which I've bound with thread and epoxy that are still shooting well, I have one old Hazel bow made in 1 hour with it's belly smothered in chrysals running right across that still shoots.
The chrysals basically warn that the bow is overstressed in that area, maybe drawing it to 29" was enough to cause them .
It's not an issue as they are barely visible, however, it's also not ideal and I decided the tiller was perhaps a tad too elliptical and a little judicious relieving of the inner 2/3 of each limb (especially the lower which could be seen as a whisker stiff) was in order.
Basically I ran a coarse file/scraper and sandpaper of the belly areas in question and also rasped a whisker off one edge of the lower limb where it was wider than the upper.
These precautions will take the load off the outer 1/3 of the upper limb, the down side is it sacrifices a hint of draw weight, we are just talking a pound or two here, so the bow is still over 45#.
Hard to tell if it's my imagination but I think it feels smoother now, hard to tell as I have a bit of a cold and I'm only good for 10 minute burst of work.
These things always seem to bite you on the backside at the very moment you think you've finished. I'd just posted some pics of the bow on Primitive Archer and it grieves me to confess to my little bit or re-tillering.
Still a stitch in time saves nine and other pithy old saying.
A bit about nocks:-
Here's a sketch of two nock styles and a shot of the lower nock which has less trimmed off and is rounder and more solid. Two reasons for this. a) it is likely to get rested on the ground. b) leaving a bulkier tip helps to stop the lower string loop falling off when it's being strung or stored upright.
Update:-Shot it through the chrono'
Normal shot (about 27" draw) 155fps.
Full draw using whole 28" of arrow 160fps.
Final Update to this post:- I'm not happy with the chrysals so I've started roughing out the better half of the log. It still has some character, but not so severe. It's those small clusters of knots and swoops that cause the problems. You need to leave a tiny bit of extra wood around knots for security, but that can leave weak points between the knotty areas... sort of damned if you do and damned if you don't. The new stave with more gentle undulations will be easier to keep an even thickness. I'll also make the tiller a bit more circular.
Mind I won't throw out the baby with the bath water and go back to a complete arc of a circle, I may make some slightly eliptical templates. Anyhow it's work in progress.