Monday, 30 June 2014

Arrow Plate Done

I've shot over 80 arrows through it now and I've done the arrow plate. I adjusted the grip and nocking point a bit too. I can start giving it decent coats of Danish oil every night now.
 The pic shows some of the features. The pith centreline and a nice blush of pinkish red round one of the knots.

Meanwhile I've been asked to make a light weight Yew longbow... one of my pet hates really, but I happen to have a skinny bit of Yew that might just do it. I've jumped in, roughing it out on the bandsaw and beavering away with a spokeshave. I'm quite optimistic despite it being some Yew that was seasoned under a leaky tarpaulin for many years and had got rather wet (not by me, I hasten to add). There is a nasty knot on one side near the tip, it was bulging up and the sapwood was all going dark, either turning to heart wood or rot, not sure which. So I've rasped it down and overlaid a long slim sapwood patch.
Been re-furbishing some arrows for the ILAA shoot next Sunday, it's a two day event, but I'm just going to the Sunday, mainly to get some flight shots with my old refurbished Yew longbow.
http://www.longbow-archers.com/keyeventsstgeorge.html

Saturday, 28 June 2014

Shooting and Arrow Pass Adjustment

I've started 'shooting in' the bow. My 'standard' arrows are a bit under spined for it but they go blisteringly fast. I've been shooting some stiffer 11/32" shafted arrows instead, they go hard and fast. I'll have to try it through the chrono' some time, but I might wire up a new lamp for the chrono' as the previous arrangement was a bit feeble (and it got shot a couple of times!)
I noticed the arrows were marking the bow a little too near the belly so I rasped off a little to adjust the curve of the side of the bow, I rubbed it with chalk and you can see the arrow now touches the bow centrally, this also helps to show where the arrow plate will go when I do it (an inlay of Water buffalo horn).
My interpretation of the marks is this (it may be wrong of course!) The lower mark is where the arrow is resting on my knuckle as I draw it back The next mark up, is where it flies from the bow slightly higher due to the nock point on the string being deliberately slightly raised, this stops the flights ripping into your knuckle. The highest mark is the flight rubbing on the bow. Maybe the centre mark is the shaft going both back and being loosed and the other two marks are fletchings touching the bow. The real point is the marks are near the centre of the bow, which is where I want them.
The full draw pic is grabbed from video... I really need to put up something to stop the glare (or adjust the exposure), anyhow it shows the tiller of the bow.
I've also taken a picture showing the thickness and ring count of the sapwood as requested a couple of posts back.

Update:-
I just shot it through the chrono' I was consistently getting 172fps with the 11/32" shafted arrows which weigh 450gn. The 5/16" arrows which are underspined gave me 178 fps but were harder to get a clean reading as they were flexing through the chrono. I'll try it for distance tomorrow.

I've eased the upper limb off a whisker, just a light touch with the rasp and then scraper to take out the marks. on it's inner third as the draw weight was 62# @ 28" and in the pic that upper limb looks a tad stiff above the grip.
It feels good to shoot, I did find it a bit heavy to draw, but a few tweaks has eased it off and I've got used to it. It's prob' had about 50 arrows through it now.



Friday, 27 June 2014

Cleaned and Oiled

The bow isn't finished yet, but I couldn't resist polishing up the nocks, giving it a wipe with Danish Oil and trying the manual settings on my new camera. I've managed to get a good pic of the back of the bow, showing the feature waggle and knots of the top limb, you can see how I've followed the growth rings where possible and worked around the knots. I need to get it back on the tiller and see how the draw weight is. It's normally very tricky to get a pic showing the rings on Yew. I used a large aperture setting and a tripod to get the pic... I don't really know what I'm doing tho' !

Update:- It's now 60# at 27 1/2 " according to my digital scale. It's impossible to really measure that accurately. Bottom line is, once it's sanded a bit more and settled in, it will be near as dammit 60# at 28"

Thursday, 26 June 2014

Looking Good

I've heat treated a couple of slight deflex areas out of each limb. I hadn't intended to, but I though it would look so much better with straighter limbs. This effectively gave it about an inch or two of reflex compared to how it was and so the draw length at 60# dropped back to 23" .
I also took about 3/8" off the top limb when I added the tip overlay, I did this to match up the limb length a bit better.
If you compare it with the full draw pic in the previous post, it just looks more even, especially when you consider it's coming back one more inch.
The tips seemed to be working too hard now, so I carefully rasped off a little here and there with the cabinet rasp to even up the tiller.
It's looking great now and is back to about 24" at 60# I've shot a few arrow from it and exercised it a good deal. I'll continue cleaning up the back and easing off the belly to creep it back to 28"
The pics give an idea of how it coming on. The grip shows the central pith line of the log up it's centre, this may open slightly as the freshly exposed wood dries. Tiny cracks always radiate from that centre, so in some ways it's good to expose it so the pith itself will just expand fractionally rather than forcing the wood to crack. the picture of the back or the grip shows how I've left extra thickness of the sapwood, this is both decorative and functional. It adds strength where the grip is narrowed and makes it more comfortable too.

The Waterbuffalo horn tip overlays are just roughed out, not polished yet. I'm working with cabinet rasp and scraper mostly now, but I'm also cleaning up the edges of the bow and the grip rounding and smoothing with 80 grit paper diabolo fashion. I'm more cautious on the back and I'm still carefully scraping here and there to follow a ring where possible and ease off around the knots to leave a little extra sapwood but not so much that it's carrying excess weight. It's all just look and feel now, running the finger and thumb along to feel the thickness of the limb checking for any thick spots or dips. Of course the thick spots tend to be where the knots are but it's a tricky compromise, leave 'em too thick and you have a weak spot between the knots. I've found that sound knots on the belly can actually be stiffer than the surrounding wood and need no extra thickness. It's the knots protruding through to the back where you need maybe a hint of extra width or thickness.
It's called experience, with a smattering of good fortune. Yew is pretty forgiving stuff as long as you don't do anything too silly. Care and patience is generally rewarded. But any bow is still a whisker away from breaking at full draw.

Update:- As I eased down the belly it became obvious that a small knot running across the belly wasn't solid, so I picked out the loose stuff and filled it with epoxy/Yew dust mix. It's back to 60# at 26" now, so that's about it as some finishing and shooting in will settle it those last couple of inches.
I had a test shot using one of my heaviest arrows which I shoot from the warbows. i used that to give the bow something to work against and to keep the speed down as the string still has the aluminium adjuster on it. From 10 yards, it smacked home dead centre
in a very satisfactory manner knocking the boss over!
It's down to scraping, sanding, fiddling and fettling now.
It will be very handsome when it's cleaned up and given a wipe of Danish Oil. I'll take it up the club for some shooting on Sunday, then add the arrow plate an fine tune it.




Monday, 23 June 2014

Yew primitive 60# @ 23"

I had a try with my new camera mounted on the garage wall. I left the garage door shut, so the lighting isn't great. It gives a comparison with the other camera. V similar but maybe a hint better, The old camera has a bigger lens and aperture but fewer pixels. This pic is a still grabbed from video. Looking good, right limb maybe a tad stiff in the outer 1/3.
I should add an unbraced pic really as the bow has a tiny hint of ref just out of the grip, then a hint of deflex.
I'll mull it over and spend some time cleaning up the back before pressing on towards full draw.
Note the lower limb has a black Water-buffalo horn overlay, the upper limb is still just self nocked for now. I did that so I could narrow the limb tip further and I didn't want to risk it splitting the wood.

Spend a good deal of time fussing over the bow narrowing tips, bringing the fade on the lower limb closer in to the grip, opening up an arrow pass a little further up into the upper limb fade.
It's looking good now and would probably take a full draw, but I don't want to pull it past 60#. Currently it's about 60# at 24" so pretty close. (That interpolates to about 72# at 28" so I actually draw it...)
Comparing the tips with my 70# longbow shows it's carrying a lot of extra tip mass. The longbow is about 0.5" circular section where the horn nock starts. This bow is more like 0.6 thick and 0.7" wide, it also gets wider quite quickly. Now I don't want it to look like a Neolithic bow with a  longbow outer 1/3rd grafted on the end, but I will reduce the tips and blend them in, taking the opportunity to keep improving the string-line.
The lower limb looks pretty much dead straight while the upper has a sprinkling of knots and a gentle waggle. The twist near the grip is still evident, but the outers are true and move nicely as it's drawn.
In the pic you can see a fair bit or the heartwood belly showing on the right limb near the grip where the twist exposes it, as you look along the limb, you can see the edge of the limb the same as on the left limb.
I've had a couple of short draw shots and it feels good. back to work for a couple of days, which is good, as it will stop me rushing it. Hopefully I'll have it up to full draw draw by the weekend and I'll try it at the club, I can't wait to see how far it will fling my 'standard' arrow as it's the heaviest primitive I've made.
Update:-
Did a bit more this evening 60# @ 25" and looking a nicer curve to it.

Sunday, 22 June 2014

Removing the Twist from Yew Primitive

The twist on the Yew primitive was getting a bit problematic as it was twisting in the same direction as the sideways waggle in the limb was trying to twist the bow. Two out of line forces acting in the same direction was a bad thing.
There is no way to remove the sideways waggle, so I steamed out the twist. The pics (one from each end of the set up show how I did it. An off cut of square plastic drain pipe contained the steam along most of the limb and a length of 2x1 was made into a wrench to hold the limb tip and apply the twist. A length of rubber strapping applied the force, held in place by my inertial restraint device (or Anvil as it's sometimes called!) The steam is from a wallpaper stripper and it is going into the drainpipe through the black flexible hose. The ends of the drainpipe are loosely closed off with foam plastic offcuts to contain the steam, I've left a drain hole at one end for the water to run out where the steam condenses. The workmate is blocked up at one end on bricks to ensure the water runs out rather than soaking the wood.
The last pic shows the result. There is still some twist near the grip, but the rest of the limb has been eased round to keep the belly of the two limbs pretty much parallel. You can see the place where the string line gets very near the edge of the limb, which of course tends to twist the limb. It's looking more like a bow now, and I've remove a bit more wood at the grip, this was helpful for clamping the bow onto the jig.
The Yew went soft with the steam remarkably quickly, probably because the limbs are relatively thin and have plenty of surface to absorb the heat. Also the steam and twist was spread out over a good length of limb.
I was very pleased how it went. I followed my first rule of heat bending.
Spend as much time planning and jigging it up as you do heating.

As well as removing the twist, I applied a little force/movement to remove a small deflex bend, which was by the sideways waggle. I'm not sure how much that took out, but I didn't want to over stress it as there are some knots in that area.

Update:-
It's now 60# at 22" and I've heated out an ugly bit of deflex from the tip of the lower limb, I haven't gone mad with it and flipped the tip, just straightened it..

Saturday, 21 June 2014

Yew Primitive Braced

The Yew primitive is coming along, it at a low brace now and pulling 60# at 20" so it's coming on well.
I've spent a good deal of time going over back getting it to a single growth ring or with the growth rings running along the length of the bow. I've left a little extra sapwood round the few knots which come through the back. The string line has been repeatedly checked and the tips narrowed somewhat. There is a big wiggle in the top limb, but this is less evident now the tips are narrower. Hopefully when it's finished the string line will just about stay inside the limbs at all points.
I left my old string adjuster with a guy in Tennessee so I turned the mkII from some soft Aluminium bar, before I made it I'd been using an old bearing which I had lying about.
Up at the club today I had a play with the new camera, got some nice slo' mo' from medieval corner. also tested a few flight arrows from Twister, I couldn't use the 70# Yew longbow as they'd have gone out of the field. I got about 200yards which is pretty good from a 47# self wood bow.
Here's a V short clip of an arrow leaving warbow taken at 120 frames per second and then slowed further with Windows MovieMaker.
You'll need to view it full screen, the tails on the medieval headgear flap about a bit and the rotation of the bow in the hand is interesting.
video

Thursday, 19 June 2014

Slow Mo' Hat Cam

I bought a new camera of E-Bay a Canon PowerShot230 HS it's a few years old but it has loads of features and in someways better than my old Kodak Z1012. It only cost me £69 which I think was a bargain. It didn't have a memory card but I used the one I got with the cheapo 60fps kodak I bought a while back just to try some slightly slower motion filming.

The big advantage is it will shoot at 120 and 240 frames per second. At 240 the resolution isn't so good but 120 fps gives a good idea of arrow flight. Note:- The video is further slowed in Windows Movie maker which allows 0.5, 0.25 and 0.125 speeds.

I couldn't resist playing about and mounting it onto an old hard hat, it took a lot of messing about to get it in the right place at the right angle so you can see an arrow go. You can see a hole above the temple of the hard hat where I first tried to mount it. I used the camera mount from a broken old camera tripod, I knew it would come in handy one day.
 It's mounted to allow for the tilt of my head in my normal shooting style. I s'pose I could use my old camera on a tripod to get some video of me shooting with the hat cam on!
video
Enough chat, here's a clip (this is the 240 fps) of course it gets compressed a bit down loading it onto here. You can also see the lights flickering at 50Hz.

Monday, 16 June 2014

Yew Primitive on Tiller and Nettle Cordage

I've been wanting to make some natural cordage for some time so I can make a simple bow from entirely natural materials. I happened upon a large patch of tall stinging nettles so I gave it a go. There are tons of videos on You tube, so I won't bother going over the process, I'll just say, it was relatively quick and quite fun. The fibres dried over night and I used some beeswax polish on them to help keep them supple and together whilst twisting it up. I'd gathered 50 stinging nettles and used about half to make about 7' of simple cordage. I made it a bit thick, for a bow string I think 3 thinner cords made up into a string would be much better.
The end on shot of the bow shows the heartwood/sapwood and gives an idea of the belly and the waggle in the far limb, which will probably be the upper one.
There is a little twist in the limbs, E.G The boundary between heart and sapwood twists as it runs down the bow. I'll allow that wist to be present in the finished bow to maintain an even thickness of heart/sapwood throughout the limbs, I'll just need to watch for any twist or sideways bend while tillering. Mind wide limbs are unlikely to bend sideways, so it's mostly twist I'll be watch out for twist.

The Traditional Bowyers Bible vol 2 has a good section on making strings, but again there is probably plenty on You tube.
video
Here's a brief video showing the Yew primitive starting to flex, I pull it to 60# maximum, it's looking good.

Saturday, 14 June 2014

Flight Arrow Video

I don't know how well this will show up as it gets compressed when down loaded. It shows two fight arrows one with my regular 35-40 spine and one with 30-35 and a slightly lighter point.
One goes much more sideways than the other, but both just about get straight after 10 yards.
You'll need to view it full screen and play it a few times. It has been cut so the two fly one after the other with no wasted time waiting for the action. A better camera and loads of extra lighting would show it better, but it's not bad for a £20 E-bay camera. It serves the purpose, it will be interesting to see which flies further, my money is on the second slightly weaker spined arrow. The shoot is on July 6th, so there's a bit of a wait.
Looking closely at the video I can see the arrows show up better as they pass over the two lamps which are on the floor in front of the target. If I do it again I'll arrange some better lighting, pointing upwards.
video
Meanwhile I've done some more on the Yew primitive, I've not done much over the last few days as we had a few days away B&B'ing ended up at the Romney Hythe & Dymchurch Light Railway which was rather fun. Had a real seaside holiday feel, and the trains really go along at quite a speed.

Saturday, 7 June 2014

Even Lighter Flight Aroww

I've just tested my lightest flight arrow yet 375 grains, it's 5/16" shaft (30-35 spine) 28" long tapered at each end with a tiny brass point. I tried it from the 70 pound Yew longbow bow, it's difficult to see exactly what it does over 10 yards, but it seemed to leave the bow and snake violently coming back straight just in time to hit the boss.
I think it would be hard to get the weigh down much from that as if the point is much lighter it would make the centre of mass too close to the geometric centre. Oddly the Turkish flight arrows had the centre of mass behind the centre of gravity! However work by Clarence N Hickman concludes it should be forward of centre. Mind he wasn't testing arrows the same length or shape as the Turkish flight arrows.
For the record a bare 5/16" shaft (32" long) from the same batch weighs 280 grains, which give some idea how light the point is.

If I get time tomorrow I'll see if I can get some footage with my camera which will show it flexing... dunno if it will work.
The bow seemed happy enough with that weight, it didn't really jar or ring. The acceleration is pretty huge so even a light mass has enough inertia to stop it being a dry loose. I did some rough arithmetic a while back and the g force on the arrow was surprisingly high.

I just re-did my 'back of the envelope' calculation assuming a constant acceleration* from 0 to 180 fps over a 21" power stroke I came up with an acceleration of 289g !!!
This seemed mad, so to check it I enlisted the help of Mr Google and came up with this article which shows some practical tests using a lower poundage bow and an accelerometer which gave results of about 200g.
http://www.gcdataconcepts.com/arrow.html
Note in their tests the accelerometer has added considerable mass to the arrow which could account (along with the lower poundage) for the discrepancy between my figure and theirs.
So, under 200g acceleration the arrow effectively "weighs" 10.7 pounds so it's nowhere near a dry loose.
Now these figures probably sound bonkers to you so please feel free to check them and correct me if I've slipped up.

*Note:- Acceleration from a longbow is not linear, it is highest over the first part of the power stroke where the draw weight is higher. This is why Clarence N Hickman designed the modern recurve bow (with the limbs angled a little towards the archer and then curving away in deflex reflex) he wanted to get a more even, linear acceleration over the whole power stroke rather than the harsh kick up the backside that you get from a longbow. He was after efficiency so that he could get decent arrow speed from a lower draw weight. Why? Because he'd lost some fingers in a rocketry accident, he's the guy who designed the Bazooka and did much work on rockets in WWII.
Of course the cams on a compound allow the designer to manipulate the acceleration curve.



Friday, 6 June 2014

Visit

I had a visit from a young chap today, he's into making bows and doing stuff which is refreshing these days. We got through a good deal of work trying out my various bows, having a go with a drawknife and marking out a couple of bows on some seasoned wood. One old half of a Hazel log had 90 degrees of twist on it but we managed to run a string line down it and rough out a bow shape on the bandsaw. A bit of work with axe and drawknife resulted in a promising looking stave. I found a bit of Yew too, it was the other half of the log that became a 130# Warbow, it was odd stuff with no clear differentiation between heart and sapwood. A couple of nasty knots meant it was no good for a warbow, but we marked it out about 30mm square at the grip and 20 mm square at the tips. I let him run it through the bandsaw producing another reasonable stave. He's been making bows from boards of unknown hardwoods and offcuts of flooring boards etc, so from the tree will provide some more experience and another dimension to his bow making.
It was a hot day and we had the shave horse outside, we even managed a quick walk in the woods tree spotting.
staves
I was ready for a cat nap by the time I'd driven him to the station.
It good to see young guys learning the craft and to give them a hand honing their skills. When I was that age there was no internet and no one I could learn from. The local library had some books and D G Quicks had a shop fairly near which was some help. There is so much more information these days which is great as it means these crafts won't be lost.

Thursday, 5 June 2014

Yew Primitives

I've sorted out my staves, there aren't any simple longbows there, but I have 3 staves that should make nice Yew primitives. I've got three people after them too, one guy wanted an Otzi bow but the information on it is a bit scarce and it way well have been all heartwood. Effectively it was very much like an English longbow, I don't really have a suitable stave and to make one without a sapwood back would need some very clean heartwood and seems like potentially an accident waiting to happen... mind if I find a length of Yew with damaged sapwood but clean heartwood I'll give it a go. Meanwhile I've offered to make a primitive instead, but I don't know what draw weight or length! So that bow's a no go for now, but I can be roughing down the staves to get them flexing.
I don't mind if he doesn't want a primitive, but I need to know so that I can make what is wanted. I have people chasing me for bows that I haven't got the wood for, which is why I would never do it commercially or take deposits for bows. I do it for the love of it and can only use the wood I have!



The one I've picked up is the longest and has a bit of a waggle in what will probably become the upper limb. One guy is after 50-60# and someone else wants about 45# at 27".
There is often discussion about splitting or sawing staves. I think there is a huge argument for sawing Yew as it's so hard to find. Once you are roughing it down with a draw knife and even marking it out with a pencil the lie of the grain will make itself known. That's why I've sawn it out with a waggle, I'm respecting the flow of the grain even with a bandsaw.

Talking of drawknives, mine was getting a bit dull and has a bit of dip in the centre of the blade where it was nicked. I'd been trawling the web looking at sharpening techniques and one suggest avoiding any motorised methods entirely. I found an extra coarse stone on the web which said it would take off good amounts of metal and refurbish damaged edges. When it arrived I was shocked at how small it was, however, when I used it, it did what it said! Mind it still required a good amount of time and effort, but my drawknife is now cutting better than ever. I've also ordered one of those big cigar shaped scythe sharpening stones which may clean it up even further and will be good for putting an edge on some of the garden tools... yes spades can be sharp!

Working a stave that is half a log can be deceptive The belly obviously shows heartwood, but due to the curvature it can appear from the side view that the sapwood is much thicker than it is. E.G The sapwood could curve right over the sides of the bow making it look entirely sapwood from the edge, whereas in reality the heartwood is bulging up in the centre of the bow... maybe a pic would help.

You can see from the pic there is a temptation to remove far too much sapwood from the back. The trick is to have a good look at the end of the stave not just the sides and belly.