Sunday, 29 May 2016

More Messing With Arrow Shafts

My mate JT brought over some 3/8" Ash shafts for making some Warbow flight arrows. They are rather coarse grained and don't machine very well... mind I hadn't perfected my travelling steady for turning arrow shafts at that point. The problem is the shafts aren't precision items, so the steady needs to hold the shaft firmly, but with a little 'give'.
I finally made the mk3 steady, which when waxed with beeswax/turps polish works nicely. It has a 3/8" hole with a slot cut right into it and two other slots allowing it to flex a tad. It works really nicely on some Maple shafts I had left over from ages ago, they were a whisker fatter than the Ash, but the steady took up the slack, mind it did squeak a bit!
It would be easy enough to make this sort of steady for different sized shafts and make a version with an adjustable blade (say a pencil sharper blade or a bit of hacksaw blade sharpened) behind the steady for use with an electric drill rather than a lathe.
In terms of spine the maple is very similar to the Ash. This got me to thinking what other woods would be good, Hazel seems like a possibility, so I strolled over to the woods and cut some shoots, I also cut a bit of Elder, which is very soft and green, maybe it will harden up as it seasons.
The Hazel may season quite quickly, I straightened the shoots by hand while they are green and soft, it turned out that one bit had been standing dead, it was much harder and it snapped as I tried to straighten it. I think some rot had set in as it was an odd colour inside. Yew would probably make a superb arrow, but there's a sad lack of decent clean straight Yew, although I'll bear it in mind for offcuts in future. A Yew Warbow flight arrow would surely be a thing of beauty, maybe with a tiny  brass point?

I s'pose I should mention, I'm turning shafts to overall size, they will then be tapered at each end with my arrow taper jig. The taper jig doesn't remove material as fast as the lathe, so it's best to use the lathe first.
Enough musing, here's a couple of pics

Saturday, 28 May 2016

Flight Shooting Fail

The grass in the secret flight shooting field has shot up over the last two weeks and was too long. It didn't stop us trying, but it took an age to find 'em and we didn't want to risk shooting them again.
They were shot from a 100# warm up bow, not the 120#.
It's impossible to draw definitive conclusions from such sparse data, but there are some tentative conclusions. I shot the arrow with the odd flights from a short draw and it was predictably short and can be ignored.
Of the other 4 arrows two were very close to each other, one was about 6 yards further and one was about 6 yards short. I noted that the flight was fairly clean  but there was some tail waggle
The furthest was the weakest spine (70-75#)
The shortest wasn't the strongest spine but was 80 -85#
I can tentatively surmise that weaker spine isn't significantly worse and that spine isn't overly critical as there was no vast difference.
I'll be measuring up some other flight arrows which I know have performed fairly well from the bow in question, and see if I can improve on those.
The downer is that we have no where to shoot for distance unless the field gets cut for hay.

A friend is giving me some pieces of parchment so I can experiment with that for fletchings. It's good to share materials, I sent some horn to one of the UK guys on Primitive Archer.
There's a good community spirit, the mini bow (24" long) I made from the broken Yew heartwood primitive got to the Marshall Primitive meet in the USA and apparently was quite impressive. The mini bows shot well, one of the guys sent some pics reckons they would get you meat if the need arose (or presumably stop a zombie when the apocalypse comes).

Tuesday, 24 May 2016

Musings on Flight Arrows

Boring post alert!
I've been asking for opinions on flight arrows and one suggestion was to select the spine by getting 'em to fly straight without flights. That's fair enough, so why do we need flights at all?... well the back end may well waggle in flight or move round in a circle, I've seen it with an arrow with wet flights the point went straight and the nock was describing a 3 inch circle!
The flights will also damp down the vibration/oscillation of the arrow caused by it flexing round the bow. This begs the question, how long does the vibration last?
So, I took one of the shafts I'm using and clamped one end in the vice, I pulled the free end out by one inch (a reasonable deflection) and let go... blimey the damn thing was vibrating significantly for at least 4 seconds! Well even at at 150fps it would still be vibrating after travelling 200 yards!
Ok there are loads of errors and approximations there:-
1. The mode of vibration is more likely to be with either end stationary (nodes) and the middle moving (anti-node), rather than the one end fixed (node) and the end an anti-node.
2.The deflection would probably be less.

So lets assume the oscillation dies down twice as quick and was half as big, so we'll divide the time by 4. That still gives 1 second which is 150 feet or 30 yards as we sometimes call it.
That pretty much ties in with the sort of waggle you can sometimes see.
Ha! Just found a better test. I tried to hold the ends and twang the middle but it wasn't really feasible... but clamping the middle and twanging both ends simultaneously produces the same result from a topological view point! Yes the vibration dies down quicker, but does go on for about a second... there, I'm not as daft as I look! :-)
Ah, but the fletchings aren't at the anti node, so they won't be damping out the movement, Hmmm I'm more confused than when I started. maybe I should try having fletchings in the middle of the arrow too? just kidding... or am I?

I'm not suggesting that this is by any means a good mathematical model, but maybe it's indicative of the usefulness of the fletchings. It's a trade off between stabilising the arrow rapidly and increased drag for the rest of the flight.
I'm pretty sure that actual testing is the only way to optimise the arrow to the bow, no way you can buy an "off the shelf" flight arrow.

Monday, 23 May 2016

First Warbow Flight Arrow

I've got it finished and shot it through my heaviest bows, which aren't really much over about 80# @ 32" but at least the arrow survived, they were sticking in at a slight angle, (nock to the left) it's pretty irrelevant with an underweight bow.
I'm not sure if the flights are too thin and flexible, it needs a proper test. The spine is only 75-80# so I think I'll make up the next two from higher spines. I'll probably fletch 'em with my usual commercial flights, but trimmed down to low profile with my hot plate feather shaper.
The nock end of the arrow has a rod of horn (approx 3.5mm diameter) glued down the centre. The end is tapered by about 4 degrees (too slide set to 2 degrees) a small flat is filed on each side and a sliver of horn glued on with rapid epoxy. The end is then bound with fine linen thread, low viscosity superglue is dabbed onto the thread and soaks in hardening the whole lot. It was then all sanded down smooth on the belt sander and wiped over with epoxy to make it smooth.
The ears of horn give a secure deep nock, but don't actually grip the string. the nock groove itself is smoother with a round needle file.
If I get 3 made up, we might get to test 'em at the weekend or one evening. (you reading this JT? ;-) )

Thursday, 19 May 2016

Turning Flight Arrow Points

This is really an aide memoir for me as I don't use my little lathe that often and I forget how I did it last time. The critical bit is turning down the neck, if the right end of the work isn't supported it will just bend or snap off. The female centre I use is just a scrap of brass rod with a hole in held in a chuck which is a bit big. When I bought that chuck on line I thought bigger was more useful, but it's not always the case, as it stops me getting the tool in close without it overhanging the tool post a long way. I expect any of you who are skilled machinists will see I'm probably doing it all wrong. Any hints or suggestions gratefully received.
I was surprised how light the point is, I could have gone a bit longer on the neck and point maybe.
Once the point is glued into a shaft they will be finished together with very light cuts to blend in a smooth taper and get a good finish.
The point of all this is to try different spines from 120# warbow (and assorted other bows) to hopefully get a clean flight.
I have a theory, I've since found it is also held by others, that you need a much lower spine than one would think for flight arrows which have to flex round the bow (as opposed to being centre shot). This is due to the lightness of the arrow and specifically the lightness of the point. There is much less inertia resisting the huge initial acceleration and thus less bending force.
I had one bloke on a Facebook group telling me I didn't know what I was talking about in a rather abrasive manner... I left the group.
I'm happy to indulge in reasoned argument or discussion, but there seem to be few people these days who understand the rules of arguing logically. You have to counter a point or explanation with facts or logic, calling someone an idiot doesn't really achieve much.
I'm happy to share my knowledge and lack of it, and I'm quite happy to be wrong!
But I wasn't going to waste time trying to explain something to someone who couldn't distinguish between a 1/4 pound arrow and a flight arrow.
I've glued in one of the points and blended it in on the lathe, (slide set to 5 degree angle) I could possibly taper it a bit more. The arrow weighs 499.8 grain which is convenient, doubtless it will be a tad over 500 when it's finished. The balance is nicely just fore of centre.

Monday, 16 May 2016

Patch and Arrow Plate Done

The 'Transatlantic' bow (American Yew belly, English Yew back) has been refubished, the patch is pretty good. The yellow arrows in the pic show the extent of the patch.
The bow needed a hint of re-tillering, the lower limb has taken a bit of set over the years and unfortunately I can't use heat to straighten it because of the glue line. The upper limb, where the patch is, has been evened out a tad which has re balanced the bow a bit.
I've only shot one arrow at about 27" draw so far. I'll shoot it at 32" when it's had another day to cure the glue. meanwhile I've added a huge arrow plate. Because it's been shooting warbow arrows with their cheese-grater whipping round the fletchings, the wood at the arrow pass had been ripped to hell.
Anyhow it's looking better now and should give a few more years service.

Meanwhile the 24" mini bow has been posted off to the USA as the "UK Entry" to the Marshall Mini Bow Challenge. Hopefully there will be some pics of the fun.

Sunday, 15 May 2016

Patch Progress and a Mini Bow

I chiselled out the splinter but it went quite deep in places and would be very difficult to shape a matching piece. I could now see the extent of the problem so I rasped out all the split, fading it out gently at either end, making sure the the pin knots were covered, mind there is another pin knot about 1/2" further along, but to extend the patch over that would have been tricky as there is a dip there. Got to draw the line somewhere, and I s'pose it's just gut feel and experience.
The tricky thing is to make the patch so that it needs very little to blend it in, I want the natural under bark surface left for maximum integrity and also to look right. 3rd pic shows chunk of Yew sapwood from which I'll cut the patch... it's got a lovely clean back.
The pics tell the story, I'll post more tomorrow when the strapping comes off.
Meanwhile, I've made the 24" bow, it's about 35# at 12"
I'm adding some finishing touches, (  sort of parrot.turtle head to the bottom nock ) and hoping to ship it out the the States for the Marshall Mini Bow Challenge :-)

Saturday, 14 May 2016

More Repairs!

The Transatlantic bow made back in 2013 for a friend of mine has popped a splinter on the back.
It's a North American Yew heartwood belly with an English Yew sapwood back.
The splinter starts at a row of pin knots and runs about 6" down the bow. It doesn't go right through the sapwood. I'm not quite sure how I'll fix it, do I let in a a narrow strip or take the sapwood down to about half thickness right across the bow? I think it's about 75# draw weigh at 32" but I'm not sure, I'll re test it once it's repaired. Letting in a narrow strip is tricky and maybe a patch overlaying that whole row of pins would be good. I'll think on it over a nice cup of tea.
You can see from the pics, the sapwood back was very good and pristine, it still has some cambium on it, but the row of pins was obviously a weak point. Just goes to show how critical a bow's back is.
I like to keep an eye on bows and maintain them.
I have plenty of good Yew sapwood, as I keep all the strips I saw off when I have to reduce extra thick sapwood.

Meanwhile I'm making a 24" bow from one of the limbs of the rawhide backed primitive just for a laugh!

Friday, 13 May 2016

Destruction Test!

The yew heartwood primitive I made just didn't want to be a bow. the back patch I did was a bit half hearted and the rawhide backing was more in hope than expectation.
So... I decided to destruction test it.
It showed up a few things, the glue line on the patch failed probably due to it being too short and not very well fitted, long and shallow is best for patches. It also showed that the rawhide may have held off the failure but it didn't stop the explosion.
Anyhow, see for yourselves! Video in slo' mo'

The two limbs are still pretty sound so I may try to make 'em into mini bows... there is a mini bow challenge on Primitive Archer, maximum bow length 24", could be fun.

Thursday, 12 May 2016

Warbow Flight Arrow &Stuff

I mended the bamboo flight arrow that had split along it's length and reinforced the nock with some horn down the centre and some linen binding. It stood up to the 120# bow but waggled in flight. probably too weak a spine and the fletchings didn't straighten it quick enough.
Flight arrows are a bit of a dark art and my opinions may be complete tosh... so read on but be prepared to disagree! There are plenty of people who know more about it than me.
There are two main main differences between flight bows in terms of the arrow. Centre shot and those that are not, of course there are variations in draw weight and length.
With centre shot you want the arrow stiff as possible, but with a warbow and other non centre shot bows the arrow is going to have to flex round the bow. Because the flight arrow has a much lighter point than a normal arrow IMO it won't need such a stiff spine as normal, as there is less inertia to resist the huge acceleration.
As an example if you draw up an arrow with a point of infinite weight it will have a hard time trying to accelerate and the force from the string will try to bend the arrow, so a very heavy spine is needed to resist the huge bending force. Conversely the arrow with a very light point will have little or no inertia at the point to keep it moving in a straight line and to resist the acceleration and it will try to kick left as the back of the arrow travells towards the centre of the bow while the point is left of centre because of the grip. Because of this a lighter spine will help a true flight by allowing it to flex round the bow..
So what am I blethering on about? My hypothesis is that flight arrows which need to bend round the bow will need to be a lighter spine than expected.

The bamboo arrow mentioned at the start of this tedious post is only spined at 40-45# much to the consternation of my mate JT who shot it from the 120# bow!
Yes it's a bit under spined but not by as much as one might expect, maybe 55-60 would be about right?
So that's what I'm trying to do... stiffen one of those bamboo shafts... but how?
I've started by drilling out down the centre of another 'boo shaft (40-50# spine form the same batch of shafts). I used a red hot length of steel wire to break through initially, but then I brazed a 3.5mm drill bit onto a length of straightened wire coat hanger and carefully fed that through with an electric drill. I'm hoping to fill the shaft with a length of garden cane which I have turned down to size.
How to turn cane down to size? It's easy to turn down a half inch length, but a long bit wobbles all over the place, so I made up a travelling steady to go on the lathe, it sits just behind the cutting tool and supports the shaft, as the cutting tool is wound along the rest follows it.
Video of the travelling steady here:-
All this is just a bit of fun, I don't know if it add much to the stiffness, but it's something to try. There are so many variables with a flight arrow. The 'boo is naturally tapered, do I have the fat end at the point or nock end? Do I stiffen the whole shaft, the point end, or just the centre section? What size fletchings etc.
One advantage with a warbow flight arrow is that it should be rugged enough to test over 10 yards in my garage, ideally I want it to have straightened up within 10 yards.

Meanwhile I've finished the rawhide backing on the primitive bow, I'm not sure how well it will stand up, but I have shot it, it looks pretty good, and if it does fail, it shouldn't explode, rather fold up or just loose cast.
DAMN! I've just spotted a crack opening up on the edge at full draw, the rawhide is holding it together, but it's just a "wall hanger" now, still at least I tried. Interestingly the patch has held , but the wood tearing about a quarter inch further up the limb.... maybe I should simply make a bow out of wood shavings and Resintite!

Monday, 9 May 2016

Warbow Belly Patch Done

I got the patch glued up yesterday so it was ready for rasping down this morning.
To help saw the patch out I used a big round steel clamp that I have lying around (part of the packing from my dust extractor) you can see it in the pic and it acted as a template for both the scoop I rasped out and the patch. it gives you an idea of the actual shape. I have seen people use the round nose of a belt sander to shape the scoop, but to my way of thinking that is far too small a radius as gives less glue area. I have no real evidence for that, just my gut feel, any comments or experience would be welcomed. I used the usual Resintite glue and plenty of masking tape to protect the rest of the bow limb, especially the sapwood... don't want glue all over that!
Enough chat, I'll let the pics do the talking.

In the final finished pic you can just see where the grain swirls around where the pin used to be. So the plug of the knot hole is now solid and embedded with in the bow underneath the patch... hopefully that should stop it pinching!

Saturday, 7 May 2016

Warbow Preventative Maintenance

I went out to shoot the 80 pounder and see my mate JT try the 120# Warbow I made for him a while back. The was a fair head wind so we didn't make vast distances. I managed 227 yards with the 80 pounder and a flight arrow.
JT showed me a bit of a pinch on the 130# Warbow I made back in 2013, it had slowly been getting more noticeable over the preceding months. With it braced you could feel it with a fingernail and I said he should let me put in a patch rather than risk shooting it. No good having it explode and then saying, I should have patched it!
The pinch seems to run from a relatively small pin knot, but when I rasped it out and dug out the knot it was surprisingly big, it's no wonder the surrounding wood had buckled as the manky wood round the heart of the pin was compressing. The knot doesn't go right right through to the sapwood which is a good thing.

I'll fill it with a Yew plug and patch over a matching piece of Yew heartwood, hopefully it will be barely visible and will extend the bow's life.
Warbows are notorious for having a short life, and this sort of thing shows the value of inspecting a bow and acting in time. Many bows will succumb to pinches round knots and they can cause the bow to take excessive set and lose poundage and cast, especially at higher poundages.
In the lower pic, my finger nail is marking how deep the probe goes into that hole! You can see I haven't had to rasp out too deep, but I've made it a long shallow scoop so there will be plenty of glue area and no sharp corners. The hard bit will be to find some matching wood. I do actually have the bottom part of the stave from which the bow was made! Mind I'm not sure if it will be long enough.

Thursday, 5 May 2016

80 Pounder Virtually There.

I've got the horn nocks done but not polished up (just added the pic of the bottom nock now it's polished). It's pulling 80# at 28" The right (upper) limb is a nice bend, it's been left a bit stiff near the grip to allow extra meat at the splice and give it a nice chunky Warbow look and feel. The extra inch to 29" isn't an issue, I'm simply avoiding pulling it past the 80# at the moment until I'm 100% happy with the tiller. So it will get a few arrows through it at 28" first.
The left limb is a whisker stiff in the tip still although I need to bear in mind it starts with a hint of reflex, it's actually a bit stiff about 1/3 out from centre. A few scrapes with the cabinet scraper should do it, but probably wise to shoot it a bit first before I fiddle too much.
Fitting the nocks usually results in me substantially thinning the last 6-8 inches or so, but it looks like it could do maybe with a tad more as it looks a bit fat!
The overall tiller is a bit more elliptical rather than circular due to the stiffened centre which should result in a slightly faster less stressed bow in theory.
There are a few checks (fine drying splits or growth anomalies in the wood) showing on the belly but the worrying ones which ran off the edge of the bow have all been removed. When they run along the belly it's not a problem, often the central pith of a skinny log will show on the belly and just adds a bit of character.
It's looking very handsome and I may even put a hint of reflex into the right tip just to match it up to the left, that may be my ace in the hole if it loses a few pounds while being shot in.
I'll get on and make a string then I can start shooting it, I think can draw it ok but it will certainly be easier with an arrow on the string.

Meanwhile the rawhide on the Yew heartwood character bow has dried so I'll take the string binding off and have a look. I'm not really looking forward to doing the other limb as it's a messy slippery job, but I am looking forward to seeing the finished job.
Here are some pics with the first limb lightly cleaned up. I pulled it on the tiller and there were no horrible cracking noises, the tiller didn't look too bad and I took it to about 26". I'll press on and do the other limb in the next day or so.
Not sure how I'll finish/seal it to make it weather proof, doubtless the guys on Primitive archer will have suggestions, maybe a modern polyurethane finish, not that I'm a big fan of modern finishes, hence the hide glue.

Tuesday, 3 May 2016

Flight Testing

I nipped out to test a couple of bows, the refubished takedown (40#@ 28") and the Yew 60# @ 28".

With the 40# 'Boo backed Yew takedown I shot two flight arrows , one bamboo and one cedar, they went 212 and 211yards respectively (slight tail wind) which is ok for a regular bow as opposed to a flight bow.
With the 60# I tried a 11/32" shaft 100gn point and a 5/16" shaft 150gn point. These got 192 and 211 yards respectively.
I then tried the 'boo flight arrow which went about 10 yards, that'cos it had split down the middle!
I quit while I was behind. The good thing was the field had dried out and was fine for shooting, the grass being relatively short still.
With the other flight arrow which has a reinforced horn nock the 60# would have gone well past the 200 but I didn't want to push my luck.

I've since repaired the arrow with epoxy, glues a turned horn rod down the centre hole at the nock, and bound round the nock with fine linen thread which then has low viscosity cyanoacrylate glue on it, that is the sanded smooth and faired in with a wipe of epoxy. I did the same binding on my longer bamboo flight arrow and that stood up to a 120# warbow.

Monday, 2 May 2016


I found some huge rawhide dog chews at "Pets at Home". One gives plenty for backing the bow with a continuous piece for each limb. I soaked the dog chew in the rain water butt overnight and unwrapped it this morning, it's pretty slimy messy stuff even after washing in sodium hydroxide (caustic soda) solution and thoroughly rinsing.
It's tough stuff and it needed tin snips to cut it. I've done the patched limb, I'll give that a few days to dry out before doing the other. I use a small deep fat fryer to melt the glue. It's spot calibrated at 70 degrees C and does a great job.
See also this post:-
The glue tend to gel a bit on the cold surface of the bow, but a quick application of more hot glue with a paintbrush helps keep it good and liquid.
It's the combination of water and heat that liquefies the glue so it takes a good time to fully harden/dry. The string binding holds it firmly in place whilst allowing the moisture to dry out, it also leaves a funky ridged surface. A waft with a hot air gun also helps to ensure the glue is liquid under the rawhide.
Hopefully I may end up with a working bow, it seems like a vast amount of work to plough into the bow, but I enjoy the challenge and if it survives, the end result will be something a little bit out of the ordinary.

I expect any of you who are my age are singing "Rawhide" in your heads now!