Monday, 29 December 2014

I'm Messing with Yew

Just started tinkering with stuff again. It's damn cold in the garage, but a few minutes here and there will get some projects finished or up and running.
I have two Yew billets splice together which just aren't right, one billet needs rotating relative to the other else it will end up with a load of twist or sapwood being much too thick along one edge. Fortunately I left the billets nice and long, so I've just sawn across the splice and I'm trimming one of 'em carefully on the band saw to  re-align it and provide a flat belly face that I can use to rest on the bandsaw table when re-cutting the splice.
It sometime feels like a big waste of time re-doing something, but in reality it's far better to recognise when it's not right and do it again. Or at least put it to one side for some further thought rather than pressing on with a job doomed to failure or mediocrity.

S'pose I should do my review of the year, but it's really a no contest!

The big highlight of bow making was the Tennessee Classic. It was brilliant to put faces to names and get a different perspective on bows and just about everything else! Hopefully in 2015 I'll get to use the staves I brought back with me and a pair of nice snake skins which I was given. I'm not a huge fan of snake skins, as snakes are so rare in the UK. But many of 'em in the US are from road kill, snakes are vastly more plentiful there and it was a very generous gift.

Over the year we had a joyous wedding and a sad bereavement but I don't really want to dwell too much on the personal, as we all have our highs and lows.

What is it with Christmas and teeth? I was having a lovely bowl of Turkey soup yesterday (one of my fave' things about Christmas) when one of my crowns popped off! So that's a trip to the Dentist tomorrow... what joy!

Here's to all my friends and acquaintances, some of whom I've had the pleasure of meeting, some have sent me kind messages throughout the year, and some are just fleeting visitors to these pages.
Lets hope some of this will kindle interest in another generation of bowyers.
Wishing you all the best for 2015, may your bows draw sweetly and all your arrows fly true!

Saturday, 20 December 2014

Winding Down For Christmas

I'm beginning to shake off this damn cold at last, I'd also given my back a slight twinge.
A few glasses of wine and a good bop at the works 'do' last night has loosened me up and got me energised again.
The sun's shining too. Hopefully after a bit of a break I'll get back to it with a vengeance.
You know how it is with a cold... you think I'll go and sort out my staves or look at that splice etc... but then you just haven't got the energy or it's too cold in the garage.
I have an arrow plate and grip to do, but it's a mistake to work on bows because you feel you should...gotta do it when you actually want to.

I've been doing some musing instead.
I have a couple of longbows to make for people and some visitors who postponed a few weeks back. I want to make a flight bow or two, and a Hazel warbow, I've got the Hornbeam and Osage from the Tennessee Classic too. maybe the Hornbeam will make a flight bow.
For flight bows do I aim at the 35# 50# or unlimited class and what style?
It's a bit daft anyway as the only bow style that precludes man made materials is (I believe) longbow.
Now if only NFAS did a flight shoot, maybe I'll get off my fat backside and E-mail them. The NFAS 'primitive class' would give self bows a chance, but would still need a seperate category for horn sinew composites as they will vastly out range the other types.
Maybe use some Laburnum I've had for ages, I want to try a Hazel backed bow at some point too.
It would be nice to get to a flight shoot next year, but I don't actually get to that many shoots, probably 4 a year.
No shortage of things to do

Sunday, 14 December 2014

Pyramid Taper Test

Even as a kid making crossbow prods I wondered what was the optimum taper on a bow limb of even thickness, or did it matter?

Last week there was a thread on Primitive Archer (PA) which skirted around the question and some people mentioned learned papers or said they'd done the test but only hinted at the result. Only one person had the balls to say they thought it didn't matter.
I wasn't sure... after all a limb with an even straight taper down to nothing will always be half the width at half it's length regardless of how wide it starts! Will it self regulate and always give the same curve when drawn?
Or will the narrower bow bend more like a dead straight bow with most bend in the middle?
Why can you never find a straight answer to the simple question?
Well after 40 years I've done the test!

Two test bows 40" long (plus 1" for tiny slim nocks) one tapering from 3" at the centre to zero and the other from 1.5" to zero. These were sawn on the bandsaw from Polycarbonate sheet. The sawing isn't perfect so the tiller isn't exactly symmetrical.
The wider bow is of course a higher draw weight, I can't actually measure it as they are both so light.

Just for completeness I've done a parallel limbed one. The difference in curve is clear to see.

The curve is near as dammit identical within the limits of my sawing.(Especially considering the huge difference in width at the centre)
One helpful soul on PA said, "Doesn't this just prove what we already knew?"
There is a huge difference between being directed to learned papers and having people allude to the fact that they've done it and actually seeing the test.
On a bow limb of constant thickness tapering to a point, does the width of the limb at the wide end change the curve of the limb?
No not with the constraints of a realistic bow limb and a realistic deflection ( according to this test... terms and conditions apply etc!)

Does it effect the draw weight? Yes.
Now we didn't need any differential calculus for that now did we?

Friday, 12 December 2014

The One Arrow Test

I made a new string for the reworked bow, taking the bracing height up from a rather low 5 1/2" to 5 3/4". The bow was marked up as 6" max but it also had 30" max draw, so even going to 6" brace at a normal 28" draw would be no problem.
I shot 6 arrows through it to let the string settle and get a feel of the bow. I then tied on a nocking point and went back with just one arrow for my "one arrow test"... no messing about aiming, just bring it up and loose.
I think it passes!

The bow looks a lot less tired now, I'll buff up the nocks, re-write the poundage and give it a good waxing.

I hadn't shot it before I worked on it as I didn't trust the string, but after this work it certainly feels like a good bow at a nice weight, I don't suppose it's lost much speed, and it it now gets drawn to a full 28" rather than the previous short snatched loose, I expect the owner will find the cast better and more consistent.

Thursday, 11 December 2014

Reworking a Bow

Always interesting working other bows even though I'm not that keen on it. Hard exotic hardwoods are tougher to work than Yew.
Anyhow this bow has a few oddities the guy I'm doing it for had put a strange rubber boot over the lower nock to protect it... hmmm well, all it's done is retain the dirt and disguise the fact that one ply of the 3ply string had worn right through!

The wear is IMO primarily due to poor nock shaping, this is one of my pet hates. As a bow is drawn the angle of string and bow tip changes from about 15 degrees to near 90 so a simple straight edged groove can't fit the string at both brace and full draw!
The bow tiller seemed to be a bit stiff tipped and somehow looked a bit off, the more I looked the more I thought the grip looked too low down the bow, and to get it to sit on the tiller I had to support it just below the arrow pass ,even then it tilted a huge amount down on the upper limb.
So, I measure the arrow pass...
It was in the middle!
N'owt "wrong" with that as such, but it's more conventional to have it about 1" above centre.
Allowing for a 4" grip and 1" arrow pass you get a compromise. It's always a compromise of some sort as the hand and arrow pass can't be in the same place.

Just to illustrate:- Take a 72" bow (nock to nock measurement) with a 4" grip.
With the arrow pass dead centre:-
The upper limb is 36" long and the lower  32" long (36-4) that's a 4" difference.
Now with the arrow pass 1" above centre:-
The upper limb is 35" (36-1) long and the lower 33" (36-3) that's a 2" difference.
So just moving the arrow pass 1" makes a visible 2" difference... that's why we usually make that compromise. Not essential, it just looks more even, after all there are plenty of asymmetric bows just look at the Japanese Yumi bow.

Here are the before and after pics of the bow at 50# and 44# (lower pic) you can decide for yourself which you think has the nice tiller if indeed you can spot the difference.
Actually it's hard to see much difference as the lighting is different and the bow id supported on the tiller tree in a slightly different position. I took the weight off along the whole limb but mostly the outer 1/3 especially on the upper (right) limb.
By the way, I've tidied up the nocks... you can see from the line I've added to the pic' how at full draw the string would chaffe over that sharp edge.

Monday, 8 December 2014

Tired Out

A long days shooting yesterday at Windsor with the ILAA, a little drizzle in the morning ,but it brightened up. However many of us took off the wet weather gear for the afternoon and were hit by an icy squally shower. Still it didn't dampen our enthusiasm too much.
Some fine shooting in fine company. The pre-shoot registration was at Combermere barracks in their regimental museum which was excellent.
I wasn't at my best so I've not taken any pics and this is just a brief post.
I took along three bamboo backed Yew bows, my old 60#, the deflex/reflex 35# and the 40# replacement for the 35pounder.
They all performed well and I gave the 40# plenty of exercise (not quite as fast as the 35#) I moved up to the 60# for the afternoon to give me more range on the long shots and a longer flight shot.
The 35# reflex deflex found a new home with a lady who enjoyed it's cast. I let her use two of my flight arrows and she was about 12yards short of the 200 yard mark which is pretty good for 35#.
It was only about 15 paces short of the 60# bow which I was drawing to about 30" shooting flight arrows which I'd made for a 100# Elm Warbow.
I also came back with a bow from one of the club guys who wants a few pounds taking off the draw weight. Not my fave' job, but it's easy to get a little overbowed as none of us are getting any younger and a bow we thought we could manage a year or so ago get a bit tough in Winters icy grasp. It's something I'll do for fellow club members or people who take the trouble to visit (bearing bottles of wine!)
For the record I just measured it at 49# at 28" (5 1/2" brace) it's signed by the bowyer as 51# @ 29" so that looks fine. I'm only tillering it at 28" as it's damn cold in the garage and it's been short drawn up to now (short drawn because it's a tad too heavy for the user).

As always it was good to chat with old friends and put a few faces to names. I had a good chat with Nick Toy who is a fellow bowyer who's name has been cropping up on the various archer forums lately.
Thanks to Brian, his charming wife and all involved in the organisation.
I must admit A long hot shower and a Sunday roast was much needed  by the time I got home.
That'll do I think I need a cuppa and a catnap.

Saturday, 6 December 2014

Chrono' Test Boo backed Yew and Hedby

There's an ILAA shoot in Windsor great part tomorrow, a good chance to try a few bows. I thought I'd shoot the Hedeby through the chrono' to see how it performed. I was waiting to hear from the lady who commissioned it, I hadn't heard for a while and thought if she dropped out, I could cut off the long handles, fit horn nocks and see what difference it made to the speed.
I got an E-mail from her this morning so I won't be sawing the ends off!

While the chrono was set up I shot the new Bamboo backed Yew through it too. Prior to this I'd narrowed the tips, reduced the nocks and got the draw weight down to the required 40#.
Here are the results.

Hedeby bow approx 47# @28" average speed 145 fps (best 149.8)

Bamboo backed Yew 40# @28" average speed 154fps (best 156.1)

The difference between the two is there for several reasons.
The Hedeby is built to look heavy but be a manageable draw weight and thus has some deflex and also the long handles adding to tip mass.
The Bamboo backed Yew is built for maximum performance consistent with the BLBS Longbow definition. As such it has no deflex or set, the belly is heat treated yew and the bamboo back is thin and narrow.
To summarize it's "show vs go" mind the Hedby is still a sweet shooter and withing the general draw weight plus one hundred fps approximation.

Tomorrow I'll take the 35# boo backed Yew Reflex Deflex bow, the latest 40# straight version (built to replace it) and maybe my Hickory backed Yew which takes a 32" draw. Not sure which I'll shoot as I'm not 100% (bunged up sinuses) still a day out in fresh air may help shake it off.

Just found One of my best flight arrows is missing it's point.... too knackered to make a new on tonight.

Monday, 1 December 2014

Target Bow Nearly Finished

I've got the nocks done, and carefully shaped them so the string sits well away from the limbs to satisfy any BLBS pedants. It's a whisker over 40# (42.6#) but that can be lost with a little fettling.
No problems of reflex or deflex this time...Here's full draw and the nocks taken with the bow braced (they are not fully polished yet).
It needs a string, arrow plate and grip.
Update:- Got the string made and tried some test shots, pretty smooth, but it will benefit from a grip, the boo backing is a tad hard and square in the hand. I tried some shots from the 35# Deflex Reflex bow which this is to replace. The DR is faster I think, but not much in it. I may get the tips on this bow working a bit more and that will loose the extra couple of pound excess draw weight.

There has been a lot of discussion of tillering on one of the forums. Maybe this picture of an ellipse drawn to match one limb may help.
The ellipse is centred on the edge of the grip/fade area. It's a fairly rounded ellipse rather than my usual arc of a circle. Quite a good fit.