Monday, 20 November 2017

My Project List

I've got lots of stuff on the go and I'm feeling invigorated. A sunny morning lobbing arrows can do that to you. Especially when you realise one of the fields had a decent length for flight shooting.
I'll write it as a list.
1. Yew longbow bow to make for a chap who bought a stave over a few weeks back.
2. Working on a "shoot through" crossbow prod:-
https://www.youtube.com/watch?v=tvkro2HlNJg
3. Heat treat and re-work an experimental Yew flight bow which was made from dodgy spliced billets which had weird bands of alternating heart and sap wood. It should be good for testing flight arrows.
4. Build a shooting machine for testing flight bows.
5. Build Yew flight bow from a good quality Yew stave, looking at about 90-100# @28" from a short stave. Hard working and fast... in theory.

I've got the prod to a 3" brace now, it needed winching back to 150# on a long string to get it braced! It's been pulled it to 110#, the tiller isn't right yet as it's working most in the centre. If I get the outers coming round I'll increase the draw length at that poundage.
I didn't want to pull it to 120# until I have improved the tiller.
I'm opening out and lengthening the slot between the limbs. There are effectively 4 limbs, so I'm trying to get each one nicely tapered.

Update:- Worked on it a bit as described above, it looks more elegant now, but still needs to work more in the outer limbs.
I've pulled it to 130# thie limbs look more even and it's coming back further. I need to get the string off (not easy!) and see if it's taking any set.
I've certainly learned enough to make a better version already.

Monday, 6 November 2017

Warbow Tiller Sequence

The bow is virtually finished, and following the comments from the previous post I'll discus it further.
I've added the final pic to the sequence and you can see how once it's braced there isn't much further to pull it back, and yet a little careful work evens up the tiller.
It's frustrating that one guy on a Facebook page got himself to this stage making a warbow, but couldn't seem to follow it through to the finish. I suspect he was taking poor advice that was easy rather than adopting a disciplined approach.
To get that sequence I took at least 7 videos and had it up and down on the tiller about twice that, it isn't quick or easy despite what some will try and tell you. Well, to be fair, maybe with the perfect stave you can get a reasonable tiller straight off doing it by numbers, but it will be at a
random draw weight.

Trying to see how much that reflexed left tip is moving is rather difficult so I taped a spill of bamboo to the limb just inboard of the knot to see how much it moves between brace and full draw.

The final pic shows the overall set, which is very little.

Sunday, 5 November 2017

Horn Nocks On and Improved Tiller

I've got the nocks on, slimmed the tips and improved the tiller it's now coming back a bit further (almost 27"). Not quite full brace yet. I'm starting to scrape out the tool marks and clean off the pinkish under bark where it hasn't popped off on it's own. Doing a little more fine tuning the tiller, get the tips (esp' the left) round a tad more and
It's taken a hint of set from the original stave so it's only slightly reflexed now, it's beginning to look very handsome now.

Saturday, 4 November 2017

Long String On the Tiller

I'm making a 110# warbow from Austrian Yew that I've had waiting for my attention for some months. It's a tricky stave with reflex at one tip and deflex half way along the other.
On one of the Facebook groups there has been someone having trouble tillering a warbow so I thought I'd take regular pictures (captured from video) to help show the progress.
I also wanted to test an observation from one of the hugely respected guys on Primitive Archer (Steve Gardner aka Badger), which is:-

If you have a "long string" that will just slip onto the bow and only dangle down 6" you can read off draw weight and length from that and it will closely tally to the draw weight and length when braced.

It's too easy to take everything one is told as fact, that would be fine if everyone was reliable, the problem is there are a lot of well meaning armchair experts out there. Of course Steve isn't in that category, but seeing is believing, so I did the test.

The top pic shows the stave with no force on it in the upper image, each subsequent image is at 110# on the string that dangles 6".
The final seperate image is with it at a 5" brace pulled to 110#.

It's an absolute pig to get the bow strung and I was having to winch it back to a full 110# on a very long string to give me room to get it braced, and that's where the confusion can lie as the very long string comes back a huge distance because it is dangling down a foot or so.

Right, so in the composite picture, the lowest image shows it at 110# at 24".
I braced it (slightly low about 5") and with some trepidation pulled it back gradually increasing the weight (video running of course)...
At 110# it came back just under 25" which is pretty damn close and very useful.


The moral of the story is:-
1. Make sure you long string only dangles 6"
2. We are all still learning!

There is a slight caveat here, when you have it braced, don't just heave it back to full weight if the tiller isn't good, as the bow will be flexing a bit more than it was on the long string. If you study the pics, you'll see the tips are coming back about an extra inch.
You'll also see that as it's coming back 15" I only have 5 more inches to get the tiller sorted!
That's the rub with a warbow, by the time it's braced you're almost there!
The final pic showing drawn and unstrung together helps to show how it's bending and where I need to take off a little wood. The deflex area middle of the right limb isn't bending enough and the entire right limb is a bits tiff.

Tuesday, 31 October 2017

Roughing Out Some Staves


Had a guy come over on Saturday with a log he'd cut about 4 years ago, I'd made him a bow previously (Ridgeback) and he wanted me to make another. From the pics he'd sent the log didn't look too promising, but once I'd trimmed off the end an had a shufti, I could see one clean face with a bow in it. There is still one iffy knot, but most of that will disappear (see pic)

After he'd gone I ran it through bandsaw and there were some troublesome areas where one growth ring had been damaged/rotted, maybe by fire, lightning, rubbing against another branch or just bad weather. Fortunately it was fairly near the centre and by the time I'd got the save roughed down the bad ring had been cut away.

The other two staves are Austrian Yew cut from a rough half log that was bought at a bargain price by one of my friends in expectation of one good stave and maybe a skinny second. Again there are some splits and shakes, but careful laying out has produced two warbow staves, they are a tad on the short side at 73 and 74" (bearing in mind I like to have a couple of inches spare on a stave), but the bloke isn't very tall and has a 30" draw so they should be ok. It's hard to tell which is actually the best stave so I'll probably work 'em down together and see which is 100-110# and which is good for a bit more.

The paler English Yew stave is prob' going to be about 60# but I've got to discus what's required.
It's good to have a few staves ready to work on, and I've actually got a spliced Yew one as well. I tend to think of this time of year as bow making season, as there's now't much going on in the garden. I'll be thinking of cutting a couple of Hazel staves too with my mate JT, who's going to try his hand at bow making early next year.... I'm sure some beer drinking will also be involved.

I went over to Cloth of Gold as a guest of Mick the Blacksmith on Sunday, had a great shoot around in good company, we weren't scoring and did 18 targets each from two different pegs, so I shot a good few arrows. My shooting seemed back to normal and I made a few decent long shots too. Probably my last outing of the year as it's getting colder, although I might manage the ILAA at Windsor if the weather's good.

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.
PS.
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...