Tuesday, 31 May 2011

Repair Work in Progress

The pictures speak for themselves, the rubber binding will come off tomorrow night and I'll then carefully blend in that overlay. All I need now is patience...
Pic 1, before any work was done, cracks indicated in red. Pic 2 the knot excavated into a clean hole and the area flattened. Pic 3 the knot after filling with a Yew plug and the area flattened down to accept the slip of sapwood which has been prepared to be glued on. Final pic with the rubber binding in place. Note the offcut of carpet on the vice jaws to protect the bow.

By the way, it's the first time I've done a repair like this so I'm doing a lot of thinking before taking action. My main plan was to avoid removing wood if possible, to maintain the flow of grain around the knot for maximum strength, (which is why I didn't drill it out to accept a round peg) and to create a smooth continuous sapwood layer over a decent length to take the tension. The glued in plug doesn't really add much other than to provide a flat surface on which to glue the sapwood overlay.

Sunday, 29 May 2011

Roving Marks Shoot

Great day out at the Robert Hardy Roving Marks Shoot run by the Medieval Society.
We were shooting at long range in very blustery conditions, I was privileged to meet some of the big names of bow making and archery.
Robert Hardy was there in the afternoon and joined some of the shooting and presented prizes.
I was pleased to have him look over a couple of my bows. Three of mine were being shot, however pride comes before a fall and there was a tiny sliver of sapwood lifting on the back of Roy's bow by the end of the day.
I'd been hoping to hand over the bow, but although he was really pleased with it after a days shooting, I felt I should bring it back home for careful evaluation and a little remedial work. Hopefully the bow will be fine , but better to be safe than sorry.
Here's a couple of pics to give the flavour of the event, which was marked by the great company and friendly atmosphere, there was a wonderful spread at lunchtime and tea and cake at the end, all extremely civilised.

The pics show the two bows I made from sister staves with particularly dense dark heart wood. I snapped them as close to full draw as I could get.

Update:- I've had a good look at the bow, the sliver of sap wood was near a knot which on close examination and picking at it with a needle file has been revealed to be more extensive than I realised.
I'll post a load of pics when I've done all the work.

Thursday, 26 May 2011

Hazel Bow Mistakes/Problems

These pics show how the lower limb is weak, the overheated area and the chrysal.
Click on the last pic to see it full size, I've marked a red line either side of the chrysal so you can see it, and how deep it goes through the limb.
Surprisingly you can see there is still a hint of reflex and it shoots ok.
The first pic has the top limb uppermost, second pic, top limb to the right.

Hopefully seeing my mistakes will encourage people who are having a go that even with a few problems and bad tillering you can end up with a shootable bow, and that it's not possible to get it right every time.
I'm not sure what I'll do with the bow, I may not bother finishing it, but it will certainly be a usefull reference for the next Hazel bow.

Yesterday there was a fire engine alongside the woodland, I shall have to pop over and have a look, maybe there is some wood down or a burnt tree which needs tidying up (and turning into a bow).

Monday, 23 May 2011

Hazel Bow Pics

The Hazel bow is about 36 pounds at 28", I've pulled it back to 29". The lower limb is a bit weak, with hindsight I should have made it the other way up with the narrower limb at the top. The top limb is a tad longer and thus less stressed, but basically I just rushed the whole thing, got a tad cocky and cut it too close on the bandsaw and it came out too narrow.
Ok it shoots, and as a light bow it's ok, but not really the standard I expect of myself, although considering the cost of the stave (£0.00) it's worth every penny.

Sunday, 22 May 2011

Hazel Bow

I can't win 'em all.
The Hazel bow is looking good, it still has a hint of recurve at the tips, but I've spotted some chrysals (compression fractures) on the belly, they look to run deep too.
It's about 40 pounds at 28" but the stiff tips effectively make the working limb shorter and increase the stress.
The chrysals go diagonally across the belly and are visible on the edge of the bow, appearing to penetrate to about half way through.
I think I went a bit mad on the heat treating and also tried to make the bow too narrow. Changing too many things from the proven design is a mistake, my scientific/engineering background should have stopped me trying too many things at once, but hey, this is fun not work!
Hmmm ok the bow looks pretty but would you rather have a wider bow with a bit of set, or a narrow one with no set and chrysals?
You don't get ow't for now't (translation for anyone outside the UK 'you don't get anything for nothing')!
I shall press on with it and see how it performs and how long it lasts. The problem is on the lower limb, so maybe I'll need some crotch protection!
A while back someone asked if I make mistakes and get failures... well that's a 'yes'.
It just makes me realise how 'right' my little favourite Hazel bow is.

Saturday, 21 May 2011

Roy's Bow and Stringing Jig

I've been working hard to get the bow finished for a shoot tomorrow, but I'd got my dates in a muddle, it's next week! At least it means I can try it up the club tomorrow instead and get it shot in.
I forgot to put my tab on when posing for this pic and the string was rather cutting into my fingers, hence the slightly short draw (well that's my excuse!)

The red grip and serving is rather handsome and contrasts nicely with the Mother of Pearl arrowplate. I've kept the nocks small to keep the overall bow length down and keep the tips light (The bow is 70.5" tip to tip). The lovely dark heartwood and creamy sapwood shows up well in the close up shots. The draw weight has been tested with my new spring dial scale, it read 62 lb first time, but then as I let it down I noticed the zero had shifted, this shows how even a spring scale spring actually stretches slightly with use, but at least this one has a zero adjustment.
I reset it and measured again, 58lb this time, of course winching it back slowly affects the draw weight, so I'm happy it's 60 lb. As an illustration, if you winch a bow back to full draw and it reads 50, if you wait a few minutes the weight will drop by at least 2 pounds and maybe as much as 4 as the wood relaxes.

The Stringing jig is made of odds and ends I had lying about, and a couple of wire fence tensioning bolts (modified a bit) from the gardening section of B&Q) It works a treat allowing me to get a nice lot of tension on the string when serving the loops, this stops a ugly gap opening up at the start of the loop when the bow is used.

Monday, 16 May 2011

Filled Nock Hole

I filled the hole with Waterbuffalo horn filing dust and epoxy, a fairly dry mix and it's turned out ok. It's surprising how much dust you can mix in with the epoxy, the more you tamp it down and compress it, the wetter it looks. It's polished better than the coarse raspings but not as good as natural horn.
the nock is a reasonable compromise between strength, keeping the feature and the limb length.
Mind once I've shot it a bit I may decide to take 1/2" off each limb!
It's hard to take a pic of something so small, and yes, I should have put a rule in the pic so you could see the scale... I hope you can see the slightly concave area just before the nock on the first pic, it's part of the interest.
You can also see it's a bit over cooked, bearing in mind how white Hazel is normally, lets just hope the tip doesn't snap off when I draw it! I'll leave it a few days to re-hydrate before stressing it.
I've realised I havn't actually checked the string will hold in that groove yet, but I'm sure I can tweak it as required, the other limb tip is ludicrously narrow, a mere 7mm wide, but the limb tip has been left nice and deep to keep it stiff, about 17mm.

Random Stuff

My old spring scale on the tiller ig is getting a bit battered and it's difficult to read it whilst trying to look at the bow. I've ordered a nice big dial scale which goes up to 200 lb, don't worry I don't want to make bow that heavy! Anyhow I'm waiting for that to arrive before doing the horn nocks on the Yew longbow so I can check I havn't made it over weight it's back to 60# at 27" now and all nicely scraped.
So Roy, if you read this and suddenly think, maybe 55 pounds would be better speak now or forever hold your peace!

The Hazel bow is coming along nicely, I got it back to 40 @28 last night and it's still not a nice hint of recurve, of course I had to fiddle with it and heat a bit more back into the lower limb... I had it set under the heat gun at 220 degrees and then forgot it whilst I watched a documentary about photo reconnaissance in WWII hunting out the V weapon sites. Whoops, it got a bit toasted, but fortunately it's near the tip which is supposed to be a fairly stiff, slight recurve.
That tip has a little feature on it, a small knot visible on back and belly, however when I picked out the bark and dead wood it turned out to be a nice big hole going right through and my nock was mostly hanging onto thin air! This illustrates nicely that the leverage at the nock is so small that you don't need a lot of material.
I want to retain the feature but also want to add a small horn overlay. I also don't want to shorten the limb. There is no obvious way to do all those 3 things at once, maybe I'll experiment with mixing Waterbuffalo horn dust and epoxy and filling the hole, I'll have to do a try out first to see if it looks ok.
I've tried it with fine horn shavings made with my rasp and it looks ok, a few pin holes in the surface and it doesn't buff up. I think I need finer dust so I've been making some with a file and collecting it, not the most exciting job. I'll use that on the bow and post a pic when it's done.

Sunday, 15 May 2011

Primitive Archery/Bowyers Meet

Great day out on Saturday, the primitive Archery meet was held at the Magna Carta Club http://www.magnacarta-archery.co.uk/ .
It's a two day event, but I could only make the Saturday.
It was a real eye opener to see so many primitive bows there and the variety and quality of the craftmanship put me in awe (see the pic left. They are not my bows, I think they were made by Peter Broad.
The people were really friendly and it was refreshing to be able to talk to people who understood the intricacies of the wood and the techniques, we were joking about stuff which would have been wasted on non bowyers. Hmmm that sounds pretentious, there were peole there wanting to start out making bows too and there was plenty of free advice and help on offer.
One of the recurring themes was that the received wisdom always needs questioning, there was a guy there (Bob?... sorry but I'm awful with names) who'd made a very long Hazel bow from a smallish diameter stave.
It was effectively a 'longbow' but with a roughly semicircular back and flat belly. He was tall with a very long draw, and I was expecting a soft trajectory, but that bow really threw the arrows.
He'd made a nice primitive crossbow too with a wooden bow and wooden trigger mechanism of a type I hadn't seen before, people were queueing up to have a go with it. There was atl-atl throwing too, an atl-atl beings like a giant long arrow (see in the left of the photo) thrown with the aid of a throwing stick. Axes were also being thrown and there was a demo of how to use a sling, using tennis balls for safety as they were flying in all directions!
People were swapping and trading stuff too so I came home with one less Hazel stave and a lovely slat of Bamboo, which I'll eventually use to back a bow, brobably an Ipe/Bamboo recurve...

I met a few people who I'd only previously met online which was great and everyone was very friendly. I shall certainly go next year and take more of my stuff, Sunday is a 'Primitive Championship' shoot, which I'm sure will take place in the same good natured spirit as the shooting on the practice course on Saturday.
My personal thanks to Wally and everyone else involved in the organistion... Oh and I left my Portsmouth football club mug there, so hopefully someone will find it a home (obviously not with a Southampton supporter!)

Thursday, 12 May 2011

Roy's Bow and Stuff

This is the last of this years Yew, I'm aiming for 60 pounds at 28". It's back to 60 at 26 at a low brace (4.5"). So it's nearly there, I've just about finished with the rasp and it's mostly scraper and files now, maybe a little rasping. Here's a couple of pics (excuse my hand in front of the lens!)

I've been mad busy building 3 bows simultaneously, I've been hoping to get the Hazel bow finished for the weekend when there's a primive archery event, but I ran into problems, yet more twist (seems to be a running theme lately), with a flat section limb it can hardly bend sideways, so if it's out of true in any way it will try and twist. Because I've put a few inches of recurve in and heat treated the belly it's all the more twitchy. Anyhow I relieved the stiffer edge, but the twist just didn't want to go... hmmm maybe rather than weakening the stiff edge I should stiffen the weak edge!? It could well be that during the heat treating I hadn't done one edge of the belly as much as the other. The 'fish tail' attachment on the hot air gun gives a afirly narrow jet of hot air which I'd run up the centre of each limb along the belly, and maybe one edge didn't get enough heat.
I've clamped it back up and heat treated the 'weak' edge, of course I've now got to leave it for a few days to see if it's worked, so it won't be ready for the primitive event. Never mind, I'll take it along as a work in progress, my trusty Hazel bow will do for shooting.
The other bow I've been doing is the 50 pound Yew longbow for myself, blimey it's fast! Almost as fast as the 75pound bow, I clocked it at 167feet per second through my chrono' and when we took a long shot at the club (about 170 yards I'd guess) I aimed really high and the arrow was in the air so long I had time to pull out a chair and read the paper.
I haven't put a grip or arrow plate on it yet, but I'm seriously pleased with the performance.

And another thing! That string making jig is pants , so I found a bit of old Dexion at work which was going spare, ( L section steel about 8foot long with holes and slots on both faces, the stuff they use to make racking). I'll use that to make a good solid jig.

Saturday, 7 May 2011

Angel Majesty

Don't you love (or hate) those crazy Japanese product names?
Ok, it's a bow string material (ludicrously expensive) which I thought I'd try.
Damn, I got the string a tad short, the stuff just doesn't stretch at all. A Dacron string which appears too short is generally just right as it will stretch a bit as it's shot in and will require some twisting to shorten it again. But this stuff just doesn't shift at all, it twangs with a much higher note than the Dacron.
The traditional bowyers Bible says that it is faster because you can make the string of fewer strands and thus lighter and it's the reduced mass which increases the speed.
Irritatingly, the string has zero information with it and the manufacturers website isn't much better, merely recomending a thread count for recurves or compounds.... hmm maybe they don't shoot longbow in Japan, and maybe their Yumi bows have traditional silk strings?
Anyhow I made a 10 strand string which I thought was going to be long enough, but it gives me a bracing height about 1/2" over my fistimelle (That's a fist with the thumb raised like a 'thumbs up' sign which is the traditional measure for a longbow bracing height... very handy).
I've fettled the nocks a bit which has brought it down a whisker but I'm not really happy, so I'll make another string. I can re-use the material from the first string on a shorter bow as it's so expensive. (Over £30 for a reel about half the size of a reel of Dacron which is about £8).
I havn't shot it as a fully finished string yet so I can't really say if I can feel the difference.
Re-making the string made me realise that I needed some sort of jig to hold the string under tension whilst I was serving it (serving is the whipping applied to protect the nock ends and centre section of the string).
I had a long piece of 2x2" which I'd made into a portable tillering rig which I used last Monday, so I added some bits to that to hold the string.
Most effective, a length of rubber strap provides the tension and the string is held by winding it in the manner of a cleat.
The string is first wound between two nails to form a long skein, lttle tabs of masking tape keep the two sides separate, the ends are tied. One of the 'sides' is whipped for about 2", the ends of the wipping are then folded over to meet each other and form a loop, bothe sides are then wipped together for the main body of the string.
Thus you can see there are half as many strands in the loop as there are in the main body, a few extra strands are added at the loops before serving for extra strength and to bulk up the string a little so it doesn't cut into the nock so much.

Friday, 6 May 2011

Mother Of Pearl (MOP)

I'm getting towards the final stages on my last 2 Yew longbows for this year.
The one I'm doing for myself has pale waterbuffalo nocks and I'm not sure what to use as the arrow plate. MOP is fairly expensive and difficult to find in a good thickness.
Whilst looking around some antique places with my wife I came across this MOP pendant only £3 , what a bargain!
If you buy on the internet the p&p could be that much, I could also see there was some nice thick sections and the quality was good.
It's rather hard and brittle to work with, but fine metalworking saws and files will cut and shape it.
The photo doesn't do it justice as it looks like cheap plastic, it can sometimes be difficult to tell with natural materials. (At the bow making demo' last Monday everyone thought my horn nocks were plastic!)

The second bow, for a chap called Roy, is coming along nicely. The heat straightening is all done and I've had it up on the tiller, currently it's back to 60 pounds at about 20 inches (that's from an unbraced position e.g the sting is just slipped onto the bow).
I've got some nice leather for grips, and I think for my bow it will be either no grip or the pale 'veg tan' leather like I used for my quiver.
I remember Roy fancied some of my dark red leather, maybe an MOP arrow plate, or the black waterbuffalo?

Monday, 2 May 2011

Beltane Festival

I set up my bow making equipment at the Celtic Harmony Camp, Beltane Festival.
It was great fun but rather tiring.
The archery club had also set up a 'have a go' with a 3D rubber Centurion and Wild boar as two of the targets. The centurion got a right pasting as you can imagine!
A group of young lads seemed to adopt me and my bowmaking, they were very well behaved if a tad boisterous, asking questions with such rapidity that I couldn't get the answers out in time.
They were sensible enough to be allowed to try the drawknife and spokeshave (their parents were close at hand) and they seemed to really enjoy using the tools.
I'd taken the runty little bit of Hazel (cut in August, pic on this blog if you really want to see it) to demostrate some of the processes and it exploded spectacularly on the tiller at 35 pounds draw weight!
A real crowd pleaser, this showed that despite simplicty of the process it can go wrong with a bang. I was crouched down winding the winch when it blew and thus avoided getting a whack on the head
The weather was glorious and I manged to stroll around and have a look at some of the other activities, drumming, clay pot making, pony rides, face painting and all sorts of stuff. Owls were flown too which is always a great crowd pleaser.
The animals at the camp had young too, there were lambs and some really cute goslings which my wife was threatening to kidnap and take home.
I didn't get much real work done other than de-barking a couple of staves, but it was fun to show off my craft.