Saturday, 9 December 2017

Awkward Yew Stave

Andy, the guy for whom I'd shortened the bow collected it this morning and was very pleased with it, we had a quick try out and he could feel the extra draw weight. We also shot the Chinese repeater and another couple of bows.
I've done some more heat work on the tricky Yew stave and it's beginning to look more like a bow, it's been a bit of a pain, but it will hopefully be a handsome bow eventually. Here's a pic of it at about 65# at 24" so it's coming along.
I took some video to show what I'd done:- https://youtu.be/8-Fk_YIYew4
The deflex dip just right of the grip makes it look weak there and the left limb is stiffer than it appears, as it has some natural deflex near the tip. There's a bit of a kink 2/3 of the way along the righ limb... other than that it's ramrod straight ;-)

Friday, 8 December 2017

Endless Steam Correction!

I got the re-work job finished on the Adrian Hayes Boo backed Ipe bow, I even found some polyurethane varnish to touch up where the tips had been re-worked. It looks very much in keeping with the original and is now 54# at 26"
I then got back to the English Yew stave which is rather S shaped, I've got it down to somewhere near draw weight but the tiller looks awful due to the shape of the stave. I've taken out some of the deflex and a hint of the reflex, and a bit more of the deflex and then some twist in one limb that was in
danger of giving no heart wood on one side and no sapwood on t'other. I'm now taking out even more of the deflex. The corrections get easier as each time there is less wood to bend as the bow has been worked down a tad. It often takes a few goes to get it right and the bow can settle a fair bit after being bent too. It's looking good but now has a bit of sideways bend ...beginning to get a tad irritating now, but patience is a virtue and I've clamped it up and done some dry heat near the grip with it pulled sideways by about an inch. The back was covered in masking tape to help keep the heat off the sapwood. I'll give it a few hours to cool down and have a look, some of the bend will spring out, if I've overdone it a little gentle heat will relax it back. It's tricky to get heat bends right especially when it's just half an inch over the length of a limb, all pretty subtle.
I want to leave some of the character, but I also don't want it to look off kilter.

At the weekend shoot there was a guy I'd made a bow for earlier in the year, I didn't recognise him at first due to his hat, but the bow seemed familiar. Once we got chatting it all flooded back, the bow has some character a bit like this one and is from spliced English Yew billets. The moor I saw of it the better it looked !

I've started on another project, a shooting machine for testing flight bows and arrows. I'm basing it roughly on Clarence N Hickman's shooting machine (pictured). I've got the bottom part done, but it's only really a prototype out of scrap timber to get an idea of how I'll build the final thing. Not sure if it will stand up to shooting a warbow.
I sometimes get people asking if I have plans for stuff, but I rarely draw plans... I can visualize things to a point, but I soon find that I need to work in three dimensions to see and feel how things go together. This part of the machine virtually designed itself once I'd hinged the first two bits together, but to try an draw it on paper or hold it all in my head was almost impossible.

There's still a lot to do and I may have the bow mounted either horizontally or canted at a bit of an angle. The trigger mechanism isn't a problem, but I'll try and make it simulate the archers fingers. I think a good firm but flexible mount for the bow may be one of the surprisingly trick bit.
I'm in no rush with this and it's a fun fill in project which could provide some interesting insights into making better flight arrows for next years forays into flight shooting.

Monday, 4 December 2017

Last Shoot of the Year


I went to the ILAA Windsor Great Park shoot on Sunday with my mate JT in his new(ish) Landrover. mmmm warm seats, nice.
We were lucky with the weather but I stupidly wore my Summer boots which are "water resistant" and we all know that means they are about as good as a sieve. There was a good turn out and much passing of hip flasks, great to meet up with everyone and I even managed a handful of scoring shots. I'd taken 5# off my Hickory backed Yew bow to make it more manageable, I was drawing 28" all day, but took it out to 32" for the flight shot at the end with a new arrow that I'd made the day before and it produced a creditable distance, up hill in damp conditions (about 250 yards).

One of the guys there was talking over his Adrian Hayes bow and saying that he is drawing shorter now due to injury and could do with a bit more poundage. It's an interesting looking bow, lovely and narrow with a Bamboo back Ipe belly and some other wood in the core. It's lovely and slim, as I've not worked Ipe before I offered to take an inch off each tip which should give him another 5# without over stressing the bow as it's now being drawn shorter.
I bought the bow home and took a quick bit of video to see what it's doing at present.
The right limb looks maybe a tiny hint weak and it's drawing about 50# at 28" and about 45 at 26.5"
Of course it's hard to measure that accurately due to parallax errors etc, but at least I've got the "before" shot... Just realised, I hadn't adjusted the rule to allow for the slightly thinner bow, but the odd 1/4" isn't going to make much difference.
I'll take an inch off each end, put on temporary knocks and see how it looks before re-nocking it.
Update:-
I've cut about an inch of each limb and glued on temporary nocks, the string has been threaded through my magic string adjusting ring to shorten it and I've had it on the tiller, it's about 53# at 26" now! So I'll have another look later to double check the tiller and measure limb lengths and then fit the nocks, I may bring the actual nock grooves in another 1/4" on each limb, but I don't want to over do it.


Meanwhile I'll also be working the Yew stave to see if it needs a bit more steam correction.
My replacement camera arrived this afternoon, very clean and it tests out fine. The old one had a small scratch on the lens when I got it off E-bay, this one is perfect, and now I have 3 batteries. there was no software disc with it, but of course I have the software on the PC from the camera. Result!
Dunno if I'm allowed to use it until Christmas tho' as it counts as part of my pressie from my better half.

Friday, 1 December 2017

Waggly Yew ELB

I've started on the English yew ELB, looking for 63# @28" it's rather waggly and first time on the tiller it looked just too weird with a deflex region looking like it was doing all the bending, a bit of an optical illusion I think. Anyhow I resolved to steam out some of the deflex to make it more manageable. The difference is quite subtle but if you click between the two pics you should be able to see it. In the bottom pic (after) the left tip is about an inch further up. Before the steam bending I could put the tips on the floor (back uppermost) and get two or three fingers under the grip, but now I can't.

I was thinking of a new camera for Cristmas, but I found one on E-bay, the same model as the one which I messed up only £40, that's the great advantage of buying the old models, you get good value for money and at that price if it gets full of Yew dust again it's not the end of the world.
I was chatting to my brother about the camera and we wondered how the dust gets in... then it dawned on us. As the lens telescopes outwards, it will be drawing in the surrounding air acting like a bellows as it comes in and out! If I have the same problem again I'll make up a jig to hold the centre section of the lens firmly so that I can replace the outer one without pushing the assembly back in on itself and screwing it up.

I'm also re-working one of my longbows, a Hickory backed Yew, it's the only one I have that's tillered out to 32" and it's a bit of a handful for a long days shooting in cold weather.
I'm hoping to go to the ILAA roving marks shoot in Windsor Great Park on Sunday, so I'm working the bow down from 60# at 28" to about 55# that should be more comfortable and if I warm up I can take it back to 32".
Most of the work is rounding the back some more and reducing the width. There are a couple of pinches on the belly so I'm leaving those areas alone. Hopefully with the narrowed tips it should still be pretty quick. Many backed bows have backs that are horribly flat and square cornered and a bit of rounding can improve the look and comfort in the hand greatly, without jeopardising the performance.


Wednesday, 29 November 2017

Damn


I was testing the re-worked prod on the tiller and the back gave way! It cracked gracefully rather than exploding, which is good as the scale stayed on the string rather than crashing to the floor and needing a rebuild.
I thought it was being videoed, but I hadn't set the camera correctly... grrr, that's 'cos I'm back to using my old Kodak Z1012IS and I'd forgotten how to start recording. I've gone back to that camera due to me rendering my Canon "M.B.R" (mended beyond repair)!

I saw a You-tube vid showing how to get the outer lens element off for cleaning out the dust (it had a ton of Yew dust in there). Hmmm, it came off ok, but I couldn't get it back together!... mind it was an E-bay purchase anyway and had given good service.
I could possibly have mended it, but my eyesight isn't what it was, I don't have the tiny screwdrivers and I'd be doing it just to prove I could, rather than because I wanted to or needed to! So I decided to bin it rather than wind myself up... My Dad could have done it in his heyday as he used to mend cameras as a paying hobby, he's no longer alive, but it brough back some memories.
Just as well Santa will be coming shortly!

The mistake with the prod was cutting out the bamboo backing with the grain all running dead straight instead of bending strips to make the grain follow the curved shape of the bow (as viewed from the front or back).
The main thing is I now have a good idea of the necessary length and thickness to reach my target draw weight. Just got to build it with some care and attention to detail
Bit of a shame really as I'd done the work on the mount, but it just means it's all ready to go once I make the new prod... that may have to wait a bit as I'm a bit fed up with crossbow prods and I haven't got any decent Yew off-cuts for the belly at the moment.
Other than all that, things are going swimmingly!
I'll pick up the Yew bow from the English Yew which was brought round a few weeks back.

Tuesday, 28 November 2017

Crossbow Prod Mount



The crossbow prod has had the bamboo planed off it, about an inch of Elm spliced onto each tip and a new bamboo backing glued on with about 1.5" of deflex. The spliced tips are curved  towards the back in a tiny reflex this allows a stringer to sit near the tips as an aid to stringing.
I've had the prod on the tiller braced (about 2.5") and drawn to 100# at 12" . I'm hoping for 14", but didn't want to push my luck before I had it mounted on the bow.

I've made the prod mount and did a quick dirty tryout with the prod bound in place with a bit of rubber strapping. The final fixing will have leather between the prod and the aluminium and will be bound on tight with 4mm rubber cord (which may be replaced with rawhide eventually).
I may glue some this pieces of wood or bamboo on the top and bottom edges of the prod to help locate it correctly.
The vertical parts of the mount either side of the track may be used to mount rubber bump stops/ string catchers, enabling a low brace and longer power power stroke.
Nervy times as I don't want to do all this work and have it smash, and even if it does work, how fast will it be?
Just as well I enjoy all this!

If all this works, eventually I'll get to work on the proper stock made from some decent timber.

Wednesday, 22 November 2017

Prod Failure Mode

The experimental crossbow pod is too strong. To reduce weight, improve the tiller and increase draw I've been reducing the width, however it came to a point where the back was too stressed and it popped a splinter with a satisfying "crack!"
Of course the splinter started at a node and I can see that maybe I'd rasped down the node a bit too much. The fibres seem to flow up at the node and as I peeled back the splinter it ran up and out of the bamboo at the next node. This gave me the idea of stripping off the bamboo and re-backing the bow. It might be another iteration of the design before a completely new version. After all it would be good to see how far I can get it back at 120#

I've learned enough from this to make a better version, a tad longer, some built in deflex, a bit less core thickness, and a thicker Yew belly to allow removal of wood from the belly for tillering rather than making it too thin in the limbs.
the final test before it broke got it to a 10" draw (measured from the belly) at 120#  which would extrapolate to about 168# at 14" . Ideally I want 120# at 14" draw at 120#

Now I have a better idea of dimensions I can cut my various components for the prod closer to finished size.
To have the prod still in one piece is hand too as a pattern.
Update:- As I started planing off the bamboo it occurred to me that I could try it again. I'd rasped the limbs such that the back was narrower, and as I planed some off I found the back was returning to it's wider dimension. I sanded it up on the belt sander and gave it another go, getting it back to about 13" at 90# . All very promising, the outer fibres of the bamboo are the strongest, but maybe going down about 1mm still leaves decent material, and maybe the back and belly strength is better matched... mind it could all just mean it performs sluggishly.
Anyhow it's all good dimensional info for the mk2 . I'll clean it up further and try for the 14" draw!