Friday, 20 October 2017

Oh Bugger!

It's times like this you wish you hadn't left a tap dripping all yesterday morning!
 I had to spend a good deal of time mopping up the garage floor, fortunately most of the boxes on the floor are plastic rather than cardboard these days. A dustpan and brush got up a good deal of the water, and I have plenty of sawdust to help soak it up.

Next irritation was my bandsaw blade breaking, now this was a 1/4" 4tpi blade with extra set which my mate Stuart had bought as a thanks for the bandsaw usage and stuff. It's a blade configuration I hadn't used and it turned out to be very good, cutting nice and straight. I'd imagined that a wide blade would cut straighter but I found the narrower blade better, also good for following curves. (my other blades are 1/2").
The blade is still pretty new and V sharp so I was reluctant to bin it.

There are plenty of Youtube videos on brazing broken blades. This blade had broken on the weld, but I don't think it was a manufacturing defect, more likely due to me cutting odd shape 1/4 logs freehand.
I had an off-cut of Dexion which made a handy guide to clamp the blade to. I just sawed two slots and bent a section out of the way, cleaned up the sharp corners with a file and the jig was ready... only problem was finding the flux and brazing rod. I really must make another draw for welding and brazing supplies.
The ends of the blade were chamfered on the belt sander, coated with flux and carefully clamped up on the jig.
I think the brazing rod I have is quite a high melting point as it didn't want top flow at first, but once the joint was really glowing bright yellow it suddenly flowed. A bit of careful filing and then I tried it on the bandsaw, it clicked a bit as it went through the guides so I put a small grind wheel in my electric drill and lightly ran it over the sides and back of the join. It now runs lovely and smooth, good job all round, taught me a new trick and I have the jig for next time.
Here's a pic of my G-clamp nest, a couple of old shelf brackets screwed to the wall and it keeps 'em all handy and tidy.

Thursday, 19 October 2017

Sawing Some Yew

I've had two 1/4 logs on the garage floor since about January and I trimmed them down a bit the other week. I've taken them down further into 2 big slabs which are wide enough for warbows and some useful off-cuts.
The wood isn't as good as I'd hoped, there is a lot of blueish discolouration in the sapwood and the sap/heart boundary is all over the place even by my standards, I think it's just too undulating, so what I'll probably do is cut it into heartwood staves, billets and slats for use in bamboo backed Yew bows or crossbow prods or experimental work like flight bows.
I won't be too hasty as it requires some thought to make best use of the wood. I dare say plenty of usable yew gets discarded because it's not perfect... and maybe this is what some people mean when they say English Yew is no good, of course the point is I'm sure you could find similar gnarly wood from anywhere, one is simply limited by choice...
What's the best Yew? The bit that you've actually got!

One pic shows how the heart sap boundary doesn't follow the rings. This Yew was fairly large diameter (about 16") rather than the ideal pipe straight 5 or 6" diameter we'd all love to find.

Wednesday, 18 October 2017

Now't Much

I took the tri-lam and re-tillered Twister to the club on Sunday. I shot about a dozen from the tri-lam, not worrying about getting a 28" draw, just shooting as I normally wood (about 27") at the big practice boss from about 25 yards or so at a scrap of paper in the centre. It seemed nice and smooth giving a reasonably consistent group, a tad left of the paper but a nice vertical line of arrows. I was just banging 'em out quick to give the bow an extra few arrows.
I then picked up Twister which had disappointed me a few weeks earlier when it had felt stiff and unyielding. That's what had led me to re-tiller it.
I was a good 25 yards or so from the target. I pushed out my left hand drew, and... thud 1/2" left of the paper... Drew and thud, 1/2" right of the paper... Drew and clatter as arrow number 3 hit arrow number 2 .
Yup, that's how Twister should shoot. My confidence flooded back and I joined the guys to shoot about 7 of the 3D targets with a good degree of success.
I took my leave feeling much happier, I didn't want to over do it as I've been getting a lot of neck stiffness when I shoot, and it's a wise man who knows when to quit.

I've not started another bow yet, just waiting for the urge to hit me, I've been giving the lathe a good clean and adjust and reading some pap sci-fi on my kindle. Those damn Zarlacks keep jumping out of hyperspace into the summer house while I'm in there reading with Emily the cat on my lap. Must transfer power from my old car battery to boost the shielding...

Thursday, 12 October 2017

Re-Tillering "Twister"

Now re-working Twister is at first glance verging on the unthinkable, as it's been my fave' bow for years (made in 2011). On a good day I knew I could punch out my left hand at a target and I'd hit it.
Recently though I'd been toying with taking off a little draw weight, also my draw length has dropped a tad and is nearer 27" than 28".
Having been shooting in the tri-lam longbow at a good 28" draw, I realised that twister by comparison felt "stacky", that's to say I'd get to about 26" draw and it then felt stiff and unyielding instead of lively and supple.
Over the Years Twister has taken a little set mid limb (more on the lower) but is still good by my test of putting it belly down on the floor (unstrung) and seeing how many fingers you can get between grip and floor. One or less is good, which is how Twister is. Two is ok, 3 is poor. It was a superb bow, but maybe the two of us aren't quite what we were, so I thought I'd ease off the outer limbs a tad and maybe that would make it feel smoother, take some stress off the mid limbs and ease off the draw weight.
To get myself in shape too I've rasped a bit off my belly ... just kidding... I've re-instated the dozen push ups night and morning.
Unfortunately I didn't take a pic before doing any work, but this first pic shows the tiller after I'd eased off the tips a tad and lost a few pounds. It's at 40# at 28" where it probably started out and nearer 45#.
You can see the tips are stiff and it's bending quite hard mid limb almost in the style of a Mollegabet bow with stiff levers for the outer third. The two circles (or ellipses as they may not be exact circles) are quite tight radius and I'd like to see the stress spread more along the whole limb. It must have been worse than this before I eased off the outer limbs.

I've heat treated the mid section of each limb with the limbs strapped down and a slip of wood about 4mm thick under the back where the set was. That effectively pulls it into the merest hint of reflex so that when the heat treating is done and the strapping off, the limb is about straight.
It's now about 40# @ about 24" which gives me some room to re-tiller whilst keeping a decent draw weight. I think what I need is about 40# at 27" and I'd like the bow to have it's original speed and feel.
I've done a little more work now and actually shot it. Here's an after heat treating both pulled to just over 27"
The curve is looking much better and I've ended up pretty much where it was when first made about 45# @ nearly 28" , I've shot half a dozen arrows and it feels smoother and faster like it's old self.
The difference in curve is pretty subtle but if you look at the chalk marks on the wall behind the right limb you can see in the "after" picture the limb is nicely on the curved line whereas in the first pic the tip is pulled inside that line with more of the bend in the middle/inner limb.
I'll probably quit while I'm ahead now!
Maybe this last pic shows the difference better, I've done the 2 ellipses and this time you can see they are flatter and the tips conform to the curves better.
Finally another try to fit ellipses as well as I can, this one shows the right limb having a slightly tighter curve, which is fine as generally you want the lower limb a tad stiffer.
Right you can plays spot the difference now!

Friday, 6 October 2017

Spine Measurement

Well we all know about spine measurement... or do we?
I've made a quick and dirty spine tester, having noticed one rogue arrow, and using my digital verniers to measure spine is a right fiddle.

A while back on an archery forum on a post regarding how point weight effects spine I made a comment that infinite point weight would effectively give zero spine! e.g If you take a warbow to full draw, put the arrow point against a brick wall (which approximates to infinite weight) the arrow will just explode when you loose (e.g it will flex infinitely).
This was tongue in cheek, but was to illustrate a point and demonstrate a way of reasoning by extrapolating to extremes.
Well some bloke "corrected" me and said I meant infinite spine.
It became apparent that the target archers way of measuring spine to AMO standard is the opposite to the traditional wooden arrow way of measuring spine!
Now this is what is technically known as bloody stupid, however I'll let you decide the rights and wrongs.
The tradition way is to support the arrow at two points 28" apart. OR any other convenient distance, and this is important for shorter flight arrows. You hang a 2 lb weight on the middle of the arrow and measure the deflection in inches. You divide the distance between the two support points by the deflection in inches. (This automatically compensates for differing support distances... clever eh?)
E.G. If we have the supports 28" apart and we get 0.5" deflection that gives 28/0.5 which is 56
So the spine is 56, this number bears some rough relationship to the bow poundage for an average bow.
Note:- as deflection of the shaft increases the spine reduces, so 1" deflection would give 28/1 = 28 spine.
The spine figures are not linear, this shows on the uneven spacing of the scale. Also note, for convenience I've used 26" between the supports.

As far as I can tell the AMO method simply measures the deflection in thousandths of an inch with an 880gram (1.94 lbs) weight applied using a 29" shaft with supports 28" apart.
Has this annoyed you yet? They are randomly mixing metric and imperial and I have no idea what the 29" shaft length is about!
BUT the most worrying thing is they are just measuring deflection. Why does this matter?

If you plot  distance between supports divided by deflection (x) as a graph y=28/x you get a curve and as x gets bigger y gets smaller.
If you plot simple deflection y=x you get a straight line and as x gets bigger y gets bigger...
So the AMO spine runs the opposite way to the old method, bigger number is weaker rather than stiffer!

Now which is right?
Not for me to judge, but I'll just mention that  bending stiffness of a beam k=p/w Where k= bending stiffness.  p = force.  w = deflection

Oh, btw, my 2 lb weight is just a carefully calibrated bag of pebbles :-)

Wednesday, 4 October 2017

Trilam all Done

I've got it finished and over 60 arrows through it (I'll take that up to 100 before final waxing). I've just had it on the tiller and it's almost 50# which is odd, as it looked more like 46# the other day, this illustrates the difficulty of getting good data. The camera is mounted about level with the bow so is effectively looking down on the string at full draw giving a parallax error. Whereas if I sit down to pull the rope my eye is about level with string at full draw removing that error, so in reality it's a tad over 47# generally it's prob' sensible to give draw weights rounded down to the nearest 5# as a bow is likely to settle a bit rather than gain weight (unless it starts off not fully seasoned).
It's been interesting shooting the bow, the arrows seemed to wag their tails rather, but a little work around the arrow pass and inlaying the Abalone helped. Then I got suspicious that maybe there was one odd arrow, so I marked the one that flew high and right with an inconspicuous dot. Next five arrows, sure enough, one waggled off right, when I looked, yes it was the same arrow. Maybe that accounts for some of my poor shooting at the last field shoot as it was marked as a number 1 arrow.
I shall try the same test with my field bow and see how that throws 'em, I suspect the effect will be
slightly less marked as that bow is prob' a tad slower.
In terms of feel the tri-lam is lovely, it feels like it would draw further just as smoothly and I've been making sure to shoot it from a good full 28" draw which is extending me slightly. It's good to be shooting more as it seems to be helping the tennis elbow and shoulder niggle. I've been doing push ups night and morning, at least 10 and 15 or so if I'm feeling bouncy.
Couldn't resist adding the pic of the grip again as it is so gorgeous :)

Friday, 29 September 2017

Tri-lam Nearly There

The outers still need to come round a bit more.
I'm mostly adjusting the tiller by rounding off the corners, so the inner third is a sort of rounded rectangular section and as you move up the limb it gets narrower and the belly gets more rounded until at the tip it's circular as it goes into the nock.
Since that pic (shows it at 27" ) I've had it back to 28" from a full brace, I've also blended in the riser block a little more so it looks a smoother transition from riser to limb.
It needs the proper string making and then it's on to the pretty stuff. I've given it the first wipe of Danish Oil this evening so tomorrow I can pore over it taking out any remaining tool marks. Then string, arrow plate, grip. Maybe I'll get a load of arrows through it on Sunday to confirm the arrow plate position before doing that.
I'm not usually one for going bonkers on the finish, yes, I want it good and my standard is probably pretty high, but on this one I'm going for broke.
If I can find the right materials I'm trying for a top notch finish. Mind there are limitations with the wood, a few belly knots and the residual marks from the heat treating of the Yew billets before it was glued up, but hopefully I've dealt with them in an appropriate manner and in any case you want some character in a bow...
Right gotta get out the sub-aqua gear and fly off to South Africa to wrestle some Abalone for the arrow plate .... or maybe E-bay has some?
Need some Unicorn tail hair for the string too ... anyone know a good source?

The pictures don't really do it justice as it's hard to photograph something long thin and shiny! This is just the first stage of finishing too, anyhow  a load of perfect lams machined and glued up with robotic precision would be soulless.

Just to give an idea of scale, where the top limb enters that nock it is 10.65mm diameter, that's why I've left the pics small.
Also note the top nock is shaped to take a stringer above the string groove and the lower nock has one big deep groove which will accommodate both string and stringer.
Should get the final full draw vid/pic tomorrow, unless I get called up for sliding wardrobe door fitting duty!
Update here's the grip and arrow plate:-

Tuesday, 26 September 2017

Tri-Lam Glued Up

I did a dry run of the glue up to make sure everything would go smoothly. I spent a few quid on G clamps (you can never have too many).
Immediately before gluing I ran each surface on the belt sander to ensure it was clean. Having clamped it I proceeded to add rubber strapping between the clamps, this was a good thing, as I could see it squeezing out more glue. After doing the strapping I nipped the clamps up again.
Note, on the glue up I've added an extra clamp at each tip, I need the full length of the bow as the Purpleheart is only just long enough, so I want to make sure it's a good glue up right to the tip.

24 hours later, I've got it off the form, cleaned up the edges with a farriers rasp and I'm now running it through the bandsaw to an approximate shape. 26mm wide at the centre section (for about 2') then tapering to 15mm which will allow plenty of slimming down in the later stages.
I've trimmed off the ends so there are no odd laminations sticking out to get snagged. I'm very pleased with the glue line, e.g, you can't see it :-)
One pic shows a thin sliver taken off with the bandsaw where you can really see the glue line. It's worth all the time and preparation, 'cos if there are gaps, then it all needs re-doing.

I've just this minute glued on a 12" riser blcok made from an off-cut left over from the 3rpi Yew. I like to have bits of wood with some history behind them rather some bit of random hardwood from an old window frame. That's me done for the day, still a bit tired from my cold, but I've been doing 10 push ups night and morning which seems to have firmed up the tennis elbow and left shoulder... been shooting half a dozen or so every day and the decent grouping has returned.

Saturday, 23 September 2017

Boo, Purpleheart, Yew Progress

I've got the purple heart tapered and joined with a short scarf joint. The Yew belly billets have been tapered, a short Z splice cut, they have then been heat treated and glued.
I've got to plane up the boo and the glue it all up. I've asked on Primitive Archer whether I'm better off gluing all 3 at once or gluing the Yew to the purpleheart first. There's a hint of deflex in one half of the yew still and maybe gluing it up to the Purple heart would pull that out. Mind I'm thinking of gluing the whole thing up with a hint of reflex / backset, maybe just an inch or so, although it probably won't take much set during tillering.

Monday, 18 September 2017

More Thicknesser Development

It's almost finished now, here's a pic with the power plane missing, but it's sole plate is screwed to the top to give alignment as it is all built up.
I've put feet across the bottom spaced so that can be clamped on to the workmate. The adjust wheel is more central now, slightly less convenient, but better mechanically, the screw that pushes upwards bears against a bit of steel plate. I've made lots of improvements to take out slop. The biggest factor is probably the thickness of the table which rides up and down smoothly with no real room to twist.
The only problem is I don't know where I'll have room to store it, maybe I need another major sort out.
Most of the wood is off-cuts from shelving that I've been doing and bits that were hanging around.
Just added a pic with it all finished and set up with a length of Purpleheart in there for tapering.

Update:- It works a treat, no perceptible ripple, bit noisy of course and you have to take the cut in stages, con't just rip a great big taper off in one go. An advantage over a sander style thicknesser is it produces chippings rather than dust. The chips are much easier to collect/sweep up. It does throw 'em out of the front with some force so you can feel 'em pinging onto the back of your hand.

Friday, 15 September 2017

Improved Taper Sled and Thicknesser

The thicknesser was made a while back from an old power plane. One fault was the adjustable plate was hinged at the back and didn't come up parallel to the sole of the plane. I've improved this by hinging both ends so it moves parallelogram fashion, being pushed up by an adjusting screw under the front edge.
The other problem was the taper sled which was wooden and not very stiff or flat. I bought some aluminium U channel and made a better sled, it is still somewhat flexible over a 3' length... but then, so is almost anything unless you go to box section steel.
I gave it a quick try out on a strip of Ash, I set it to quite steep taper and a deep cut. It did the job but with some chattering.
I learned a few things.
1. Stick the whole lamination down with double sided tape.
2. Only take a fine cut, and/or maybe gradually increase the taper.
3. don't try to pull it back out with the plane running. It will take other cuts and spoil the work

I'll have another try on a bit of scrap and report further.
Some of these taper/thickness machines that people make use a drum with sandpaper on, I reckon they must take an age to run through if you are taking off any amount of material, though they doubtless give a better finish. I imagine using this for rough taper, then running the lamination over the belt sander.
We'll see how much wood I ruin before resorting to working staves ;-)

Update:- I've given it a go with finer cuts and it works well, there are still some improvements to make as the parallel motion doesn't work at low angles and there isn't enough height for thicker billets. The wooden adjustable plate wasn't flat, but a few strokes of the plane have improved that.
I'll work at the design to try and make it good and rugged and versatile. It looks promising.

Saturday, 9 September 2017

Next Project

I'm working towards making a tri-lam ELB for a woman who already has a couple of my bows. Laminated bows are something I'm not particularly into but I happen to have the necessary materials.
I've recently bought some more bamboo and my mate Matt from Cambridge longbows gave me a purpleheart lamination some time back.
I'm thinking Yew belly, Purpleheart core Bamboo back.
With a view to improving my Thicknesser/Taperer that I made from an old power plane I've bought some channel section aluminium to make a stiffer adjustable taper sled.
For those of you who have no idea what I'm talking about:- A taper sled is like a tapered plank, you clamp or stick a lamination onto it and run the whole thing through a planer/sander etc and it comes out with the lamination tapered to same angle that you set the sled up to. E.G The lamination and sled together come out parallel, thus if the sled was tapered the lamination now has the equal and oposite taper to make the overall pair of  'em parallel. Anyone who still doesn't get it, draw a long thin rectangle with a diagonal line from corner to corner, label the lower portion "sled" and the top portion "lamination"...  you can colour them in too if you like ;-)
I'll post some pics of the tapering sled and thicknesser when it's finished... mind it may be some time as I've a load of shelving to build (so I'm reliably informed ;-) )

Meanwhile back at the story, the woman in question likes her pink arrows and pink fletchings, so I thought I'd make a very "girly" bow and I've experimented with some coloured acrylic for nocks. The acrylic is sold as pen blanks. I quite like the effect but it is deemed not to comply with the rules for longbow which specifies Horn Nocks... that's NFAS and AGB. All a bit silly really as that doesn't allow bone or antler either of which would have been used.
I did a quick try out putting a nock on an off-cut of Yew.
It turns out she wants horn anyway and like how I do my nock at the moment. Still it was a bit of fun and the pen blank only cost a fiver (enough for 3 nocks)

Wednesday, 6 September 2017

Update on the Crossbow

I tried the prod on the tiller and it was just over 100#, but I probably didn't get it quite back to full draw, I didn't want to risk over-straining it. I plucked up courage and had half a dozen test shots and then tried it 3 times through the chrono' (with the heavier commercial bolts), average was about a disappointing 170fps. I then tried the old prod with patched and repaired belly, using the same bolts of course and it was about 5fps faster!
The new prod took a hint of set so that it needed very little flexing to get the string on. The old prod required a little more flexing despite being about 2 " shorter.
My conclusion is that the Yew is a better belly than the bamboo... of course this may only apply to this particular yew and this particular boo (I don't think it's Tonkin boo, which is considered to be the best).
It also illustrates the dilemma of crossbows, trying to get decent performance from a manageable short prod whilst maximising the draw length, without resorting to bolts that are really too light and risk damaging the prod.
I've added a pic, showing brace and drawn superimposed so I can see how it flexes.
I'll probably re-visit this at some time, and if I can get up to 200fps I'll invest in a scope and try it at a field shoot. It's not that much faster than a good primitive at the mo', after all Twister has been clocked at 166fps (prob' a bit slower these days).
One of the Guys on Facebook was suggesting heat treating the inner faces of the boo, but if you've been following this project you'll realise I've gone through enough experiments for now!

Any how onwards and upwards onto my next project which is...

Tuesday, 5 September 2017

Prod Testing

The crossbow prod looks and feels pretty good, it's about 1/2" short of the full brace height and I haven't actually cocked it yet.
The nocks have been made much more substantial than the previous ones and have been reinforced and shaped by binding with fine linen thread which is soaked with low viscosity superglue as it is bound on. The glued thread is quite solid and can be filed and glued again.
I've videoed it being drawn so that I can look at the tiller.
I will tidy it up, enlarge the shoot through hole to take the larger fletchings of the commercial crossbow bolts, increase the brace height by twisting up the string and then eventually shoot it, with some trepidation.
Oh, yes, I must remember to glue on those horn string catchers that I'd put on the previous version, I'm sure they are a good thing.

In the pic where you can see the whole prod, you can see the line along the centre where I have put two slats together to give a flatter belly.

Monday, 4 September 2017

Bamboo Belly for Crossbow Prod

I'm still messing with the crossbow prod and the bamboo as I've just bought a new batch of boo slats.
I get a decent batch and go halves with my mate Matt from Cambridge Bows.
He came over on Saturday to collect his half and we had a good natter, I later checked up on some of his Youtube videos and his website... excellent.
I wanted to get the bamboo to be as wide and flat as possible for the belly but without loosing the strongest fibres which are in the outer layers. By sawing the bamboo slat down the middle and planing the two bits individually, I could then put them back together side by side to give a flatter pied like  B rather than a D, the pic shows what I mean. I don't know if this is really worth while bu it does give a more even thickness and I can stagger the nodes slightly too.
I've got one side glued up and will do the other today, I'm a tad worried that it will be too high a draw weight, but it's all good fun

Meanwhile I went out shooting with JT and some others, they were lobbing warbow arrows at a flag, but I made a target from an old duvet that was being thrown out loosely rolled and put into a woven rubble sack. I was shooting at it from shortish ranges varying from about 10 to 40 yards trying to get my eye back in with Twister my field bow. The target was excellent, it stopped the arrows nicely without getting shot up, being light it tended to move a bit and absorb the impact, hicghly recommended as a quick cheap target.
One of the guys who was shooting was very taken with the coarse ringed warbow I'd made a while back. I had intended to keep it as a specimen bow, but what's the point of a bow that doesn't get shot? So I decided to let him buy it and he was grinning from ear to ear. he was telling me that there is no comparison in the feel of the Yew as against his laminate. I knew I'd made the right decision to let it go, as I still have an off cut of the wood and it's blogged up on here for future reference.
Just added the pic of my old Yew longbow to illustrate that you don't need to follow a growth ring, this is a response to a question asked on one of my Youtube videos.

Monday, 28 August 2017

New Arrows, Bolts and Stuff

I went to a 3D shoot at Aurora on Sunday with Mick the blacksmith, gorgeous weather,excellent shoot in good company with great catering. I was worst in our group of 5 only just scraping 406 over 40 targets, but my tennis elbow had flared up and I also felt like I had a 6" nail lodged under my left shoulder blade (note to self... please please use a stringer when making heavy bows). Feel free to use these excuses yourselves...
There was plenty of good natured banter... on one target I was up first, a longish shot with a big tree limb diagonally across about 6 foot in front of me. I thought the trajectory would be flat enough to just go under it... thud... the arrow smacked into it in spectacular fashion sticking in nicely, there was a suitable amount of cussing and witty remarks. I stepped forward and hit the target with the next arrow. Mick stepped up (he's a better shot, but his bow maybe has a slightly softer trajectory as he has a shorter draw)... I though he'd judge it right... nope... "thwack" he buried his first arrow right next to mine, and on digging them out we found a third arrow point buried in there between ours!
One other strange occurrence was on a relatively innocuous wolf target at a shortish range, Mark who was shooting in a very controlled and consistent manner proceeded to demolish 3 arrows by putting them all just over it and smashing them into the coppice of sweet chestnut just behind the target, he was as nonplussed as the rest of us.
I improved slightly near the end of the shoot, but just couldn't seem to get that confident feel of distance/trajectory that one has on a good day. I also managed to smash the points off 4 of my new arrows grrrrr.
Mick uses very long two part screw in points which seem to survive better (mind he misses less too!)

Meanwhile I've still been tinkering with the crossbow, I bought 10 commercial bolts (Aluminium alloy shafts, screw in points, plastic fletchings) and modified the crossbow to take them. I had to deepen the slot in the bow mounting for the cock feather and widen the slot in the nut of the trigger mechanism. The fingers of the nut are aluminium alloy, so I clamped it up tight and put it under the pillar drill with an 8mm bit in the chuck. Taking the drill down very very slowly I managed to mill it out, and a bit of work with needle files completed the job. A test shot showed it worked fine and it felt a bit smoother with the heavier bolts.
Talking of crossbows, a lady at the shoot on Sunday kindly let me have a shot with her Jandao crossbow (90# draw weight) it was good to try one with tele' sights and I made sure not to hit her bolts.
" 9 o'clock in the red" I said to her and promptly shot the bolt just there. I forgot to take the safety off initially, I didn't know where the damn thing was, and if you have to wave the bow around whilst looking for it, it is rather unsafe! She was about as old and grumpy as me and I don't think she really understood that I knew what I was talking about when I was saying I didn't think safety catches were really necessary (maybe some readers won't understand my view either). Anyhow that makes it even more kind of her to let me try it.

Thanks to all at Aurora for putting on an excellent shoot and importing the lovely weather.

Tuesday, 22 August 2017

Finishing off A Part Made Bow

Finishing someone else's work is always interesting, it's nice to see the job completed, but on the other hand it can be slightly frustrating.
Mind it saves time as the mistakes have already been made for you and all that's left to do is to correct them ;-)
This stave is handsome Yew, nice colour, fine grain, sapwood thin enough so that it doesn't need reducing.
The problems are:-
1. Some slight lateral bend which has one edge dead straight and all the width taper on the other side. Fortunately there is just about enough tip width to rasp away the straight side to improve the alignment.
2. There are some seriously thin spots where the belly seems to have been taken down even and straight ignoring dips in the back. One of these near the grip is thinner than much of the mid limb section!
3. The belly has been shaped to almost a semicircle... people make the mistake of thinking a "D" is like a Norman arch or a semi circle. If you look at this actual "D" as if it's a bow the sides of it are flat. If a bow is shaped rectangular section and the corners taken off you are pretty much there, it also leaves room for some minor adjustment. A little cosmetic rounding can be done as part of the finishing.
4. There are tears and gouges at various points where an edged tool has dug in against the grain.

Basically the overall effect is a bow that, at a quick glance looks basically ok on the tiller but I was only happy to draw to about 24", it's bending relatively evenly on each limb but most of the bend in in the middle. That's fine by me 'cos that's how I start the tillering process, however I think this bow was seen as being nearer the end of the process.
First job, was to rasp the tips to improve the string line (I did this before even putting it on the tiller).
next I marked all the thin areas with a big "L" for leave, then it was reducing all the thick areas and getting the limbs tapering down from the thin point near the grip.
I've put horn nocks on now and it's looking good now but isn't going to make the 100# initially requested. Mind when I first put a low brace string on it, I immediately commented "That won't make 100 pounds ", because there's no way I can string a 100# bow even at low brace.
I've got it back to 30" at full brace now and it's about 70# (allowing for the scale being about 1/2" out)
The right (upper limb) is stiff, so I have reshaped the nocks and reversed it having the stiffer limb as the lower now.
The nocks are a nice chocolate colour with pale streaks.
Video here:-

Saturday, 19 August 2017

Messing with Bamboo

I've been reading around heat treating bamboo, and like a lot of stuff it's all rather confused and poorly defined with conclusions ranging from, it makes it worse, to it makes it better.
Well I have an off cut from my crossbow prod making which is planed to a nice flat one side with the outer surface intact on the other. So I cut this diagonally to make two tapered limbs I did some bend tests with the limbs up either way and messed with some heat treatment, but it was all rather inconclusive.
One problem I think is that simply  hanging a 2# weight on the tip wasn't giving enough bend to be significant. Anyhow here's the question:-
If you were to make a bamboo bow from one piece, would you have the back of the bow as the flat planed inner bamboo or the hard, shiny outer surface?
The received wisdom is that the strength of Bamboo is mostly in the outer fibres and that most materials like wood and bamboo are stronger in tension than compression. Now this would suggest that you's want the stronger side on the belly.
Of course I could just look at a Youtube video of how a Batak native guy makes a bamboo bow, but I do like to check out stuff for myself.

So, I glued and bound the two pieces together to form a bow flat faces meeting together for a few inches in the middle, made simple nocks by binding thread round the tip and letting low viscosity superglue soak in (V quick and effective). I put a string on and pulled it which immediately showed it as much stiffer in one limb than the other. The hard glossy outer bamboo to the belly was the stiffer limb. The preference for having it this way round is also shown by the fact that the other limb (glossy outer as the back of the bow) took a bit of set.
Now, here's the supplementary question for a bonus point:- How will the flat planed bamboo surface hold up as the back? Will it splinter at the nodes?
What is the point of all this?
Well if you have a bamboo slat and want to make a V quick simple boo bow maybe the counter-intuitive shiny side as the belly is the way to go.
Just in case you didn't watch the video, yup, that's the way he did it :-)

Still dunno if the heat treating made any difference... so many experiments, so little time, and the kitchen still isn't decorated. Slow and steady wins the day ;-)

Monday, 14 August 2017

Coarse Grained Yew Test Shots

I got some video this evening of my mate JT shooting the coarse grained Yew. It seems to shoot pretty crisply, and I left it with JT so he can give it a more thorough work out at his leisure.
Meanwhile I'd been tidying up the garage, finishing some new arrows and spending the day doing my yearly batch of cider 12L this time.
 Once I've got the cider making kit cleaned and put away I can get on with some bows. I had a visitor last week who brought a partly finished bow from a friend of his to be finished and one from a well known bowyer that was a bit stiff in the lower limb. I rasped a little off the belly while he was here and had it up and down on the tiller a few times to check it was better.
I took care not to over do it, he can shoot a good load of arrows and see ho it settles down. It's always better to proceed with caution else you can take off too much and next thing you know you've gone from a 80# bow to a 40# bow!
I like to do small jobs immediately rather than have a stack of jobs which can easily get forgotten amongst the clutter of the garage.

Friday, 11 August 2017

Coarse Grained Yew gets to Full Draw

It's back to nearly 100# at 30" still at a slightly low brace, but I'll let it get shot in rather than stress it on the tiller.
It looks very weird but that's a reflection of the unbraced shape. The wood certainly looks handsome and I can't wait to see how it shoots at the weekend.

It's looking good now, I don't know if it will loose weight or take set but it's pretty much felt like almost any other bit of Yew, silky smooth in places, grain tearing in others and needing the rasp, creamy waxy sapwood. Almost no knots or problems except a few pins and one small dark patch in one ring which didn't seem to go very far.
The waggle is a bit extreme and I used heat to take some of the bend out, but one can't expect to completely straighten something that severe. The heat was also used to stiffen that area a bit as the bend tends to be a weak point.