Another Year's Round Up

Christmas has just about wound down, we'll be making a robust Turkey soup this afternoon which I always enjoy and hopefully we'll ease off eating nibbles etc until New Years Eve.
I'm trying to get back to normal and doing some stuff in the garage. I got some nice useful presents.
A Taper reamer for cleaning up the taper in my lathe headstock mandrel (work in progress already).
Some nice waxed sash cord for my tiller rig, it's a waxed cotton braided outer with a polypropylene (I think) inner core. It's a tad irritating that they don't quote a breaking strain or safe working load, but I think it should be fine. It has a much nicer feel than the nylon rope I have on there at the mo'.
A book of "simple steam engines" that I can maybe make on the lathe and mill, some other books too.
I've also got a nice zip up cardigan that I'm "allowed" to wear in the garage ;-) rather than those that are for "best". I don't really differentiate, as long as I'm warm and my arse is covered I'm not fussed about clothing, but I take advice on what is appropriate attire!

I got some draught excluder too that I'm going to use on the bandsaw to improve the efficiency of the dust extraction. I've already made one mod, which was to add a block of pvc foam with a slit cut in it to stop sawdust being carried up into the top of the bandsaw from where it falls back down onto the work. It was just a quick try out held in with double sided tape, but it is quite effective.
I bought myself a present which I didn't open until Christmas day, some cheapo bright yellow carbon arrows from China to turn into nice visible crossbow bolts. They will give me something to tinker with (I've ordered extra screw in points and inserts, I'll prob make the nocks myself)

I've looked back over the blog to see what I've actually done over the year, as I though I'd not done much.
Four Yew ELBs, a Yew flight bow, I worked with my mate JT mentoring him as he made a Yew warbow (I had one explode on the tiller too)
Two Yew Primitives, a pair of Hazel Primitives, one of Plum and a little bamboo bow for visiting kids to use.

So that's about a bow per month, which is nice...
I made a shooting machine which was useful for observing flight arrows as they leave the bow and this helped me achieve my new PB for a self bow (Osage) of 341 yards. I'll push the bow a little harder and try to improve on this on a suitable day when the ground is soft and the weather is good.
My crossbow project went through about half a dozen iterations of Yew/Bamboo prods before I resorted to fibreglass.
The workshop had a bit of a reorganisation to accommodate a second hand micro milling machine (Clarke CMD10) which has been very useful for the crossbow parts once it was repaired and refurbished.

All in all a pretty constructive year, I even managed to do most of the things on the "jobs around the house list" ... in fact I've already done one thing off next years list, which was fixing some kitchen cupboard doors which were graunching and would have driven us mad whilst trying to cook Christmas dinner.

I have a few projects lined up for the new year including making a jig to do fancy 4 point footings on arrows.
Wishing you all a great 2019, may your arrows all fly true, and may those that don't remain clearly visible!

40# Yew Distance Test

My mate JT picked me up and we went over to Now Strike Archers near Chelmsford to lob some arrows, have a natter and to enjoy a beer and bowl of chips on the way home at the Rainbow and Dove on the outskirts of Harlow.
At least one of us, Mick Black made a festive effort! (with a wonky warbow)
The Yew bow shot very nicely and I must have put about 40 or 50 more arrows through it.
My regular arrows were making 180 yards (very slightly down hill, no wind) and the flight arrow* managed 217yards.
The wind freshened into a slight head wind later which was limiting the regular arrows to nearer 170 yards, all of which is very respectable for a 40# bow.
Note:- Distances measured by laser rage finder.
*The flight arrow was just a quickly re-worked old warbow flight arrow, so it was only a little lighter than my regular arrows (348gn vs ~400 gn). it was also a whisker too stiff. The implication being that a reasonable clout arrow would make a similar distance and a well tuned slightly lighter flight arrow could maybe get another 10 yards.

Yew 40# ELB Finished

This'll be my last bow of the year ... probably :-) ... !
I've made the string, shot 30 arrows through it, done the arrow plate and leather grip. It's very handsome with some interesting features including an odd line where the sapwood becomes darker, this shows above the grip  where the tail end of the splice shows.
I don't think the process whereby wood turns from sapwood to heartwood is fully understood (certainly not by me!) but it seems to be a bit random.

Because it's from book matched billets the undulations on each limb are nicely matched, and you can see the bow has a nice overall straightness, thanks to a bit of heat bending early in the tillering.

The knotty feature is on the lower limb about 10" from the tip.

I expect I'll do a review of the year as the next post, but don't s'pose I'll post much over the festive season. So just in case:-
Seasons greetings and a happy Winter Solstice to one and all.
May your fletchings stay dry and your arrows fly true.

40# Yew ELB Virtually Finished.

I've fitted the horn nocks, the top one is black, and the bottom one has turned out to be very dark brown! I tapered the tips/outer limbs to blend nicely into the nocks, getting them to flex a bit more.
If you compare with the pic in the previous post you can see the shape is more full bellied.
It needed some careful work on the knots and dips near the tips, making sure there were no thick spots.
It's now pulling 40# at 27", I'll leave the last 1" of draw until I've made a string and I can shoot some arrows through it to get it "shot in".
Note, an extra inch of draw only equates to about 1.4 pounds increase in draw weight.
I made a video here :- https://www.youtube.com/watch?v=gYwckQDlBE8&t=7s
And here's a still showing it at 40# @ 27"
It may want a leather grip and arrow plate, I'll consult the guy who commissioned
it.

Correcting Bad Tiller

I was tempted to call this post "A Tillering Tutorial", but thought that sounded pretentious. The point of it is to show that we all have problems and that a methodical approach will get it sorted.

Target weight/draw length 40# at 28"
The bow is made of spliced billets which can sometimes give a slight miss match to the way the limbs behave if the wood is from two different staves.
To cut to the chase, I've got it at a low brace and pulling to 40# at about 19" or so. Always pull to full draw weight as long as the tiller looks ok.... errr.
I got a shock, the tiller looks hideous, but let's not panic, let's look at it dispassionately as there are several things going on, all of which all work together to make it look awful.
1. There is a slight downward bend in the lower (left) limb just left of the grip.
2. There is a slightly weak point in the left limb at the bend mentioned above.
3. The right limb is stiff.
4. I had it sitting on the tiller slightly too far to the right and was pulling the string a little too far off centre.

I check the simple things first, I re-position it on the tiller and even try it round the other way. It still looks bad. I also unstring it and look at how much of that bend is in the stave (probably a couple of inches).
First fix, I use heat  to remove that bend (15 minutes with a hot air gun and the bow strapped up).
Ah, it looks great unstrung, but still ugly as sin on the tiller.

I take some off the right limb with a rasp, but it doesn't make any difference... it just doesn't seem to want to bend any more. It does have some stiff areas where there are knots, but I want to get some method into the panic.

I compare the thickness of the right and left limbs where that bend is (about 6" from the centre line) using my verniers as a go/no go gauge rather than an actual measurement.
Ah, the stiff right limb is indeed thicker! (despite looking generally thinner, maybe it's just colour variation or heartwood/sapwood difference)
I rasp that area of the right limb until the verniers will just slip over it.
That gives some sort of reference point at the start of the limb. From there I can slide the verniers along the limb, and of course it should become loose as the limb gets thinner. It soon jams on a thick part where there is a knot. Now conventional wisdom tells you to leave some extra at a knot, but how much? I know I have plenty of draw weight still to play with, so if I rasp it down until the verniers only just fit over it, that will still be a little thicker than it should be, (because the limb should have tapered a bit by then). I then check just beyond the knot and the verniers rattle loosely at that point, so I adjust them to be snug and slide them along the limb some more.

I do this along the limb to check that the knots aren't too thick and that there is a gradual taper all along. By the time I've finished I've taken off a good deal of wood with the rasp. I've also taken care to look at the limb from both sides as it's easy to work at an angle giving an uneven thickness across the limb. Having taken some off the belly, the corners where sides meet belly are now a bit sharp, so I rasp these corners off.
Back on the tiller ... groan... the right limb is still stiff... will it never bend. I take the bow in my hand and draw it rapidly back and forth about 20 times, and then decide to try it the other way round with the stiff right (upper) limb as the lower instead.
I re-measure the centre of the bow, mark the new arrow pass 1" above the centre line and put it up on the tiller.
Much better...
Quit while I'm ahead, and decide that writing this up will be a useful post for everyone getting frustrated with limbs that won't bend!

Now I've taken more pics and you can see the improvement.
The main point is that in correcting the tiller the draw has now increased from about 20" to 24", the tiller isn't perfect yet, but it's well on it's way to decent tiller and 28" draw.
Hopefully this shows why you need to get the tiller sorted early.
It's ready for horn nocks now, which will involve tapering the outer limbs too and should get them coming round more.
Youtube video here:-
https://youtu.be/kWaO9K4yko8

I see someone has ticked the "explain more" box. I don't really know what specifically explain. Maybe it's the FAQ about why I have the bow tilting to the right and why reversing the bow on the tiller can make a difference?
To explain briefly, the bow is held at some point roughly in the middle, but the arrow sits above that and the string is pulled in line with the arrow. So the whole thing isn't symmetrical! This doesn't make too much difference on a long bow, but can be very significant on a short bow. If you clamp a bow dead centre, pull the string from dead centre and tiller it like that, when it is held in the hand and shot, the tiller will look slightly off.

Visitor Bearing Yew

I met a new friend on line who's getting into making bows, he'd been reading the blog and I'd offered some advice on tillering. He'd also offered some Yew, but being an old and lazy git I didn't really feel up to the 90+ minute drive each way and heaving yew around (in my defence there were some home issues too at the time)
Anyhow he volunteered to bring the Yew over and spend some time in the garage, seeing what I get up to.
We had a great time, shot the Chinese repeater and my little crossbow, but most of the time was spent re-tillering a Warbow that he'd bought. It raised some interesting questions about tillering.
The bow was of about 130# and had apparently been tillered to 33" .
There's no way I'm going to heave an unknown bow back to 33" on the tiller, so, what draw weight and length did he actually want? About 100# at 32" was the target.
The dilemma is, do we pull it to 32" and see what it is now for comparison or just pull to 100# and see where we are starting from? Well boys and girls, can you guess which I went for?
Yes, pull to 100# 'cos that's the target weight. Well we didn't even pull it that far straight away as we watched it flex and critiqued the tiller... Which is the stiffer limb? Where is it bending most? Can you see/feel any thick spots?
Anyhow it was 100# at 27" which we could interpolate to the draw weight at 32".
Divide 100# by 27" to give pounds per inch and then multiply that by 32 which gives 118.5 or near as dammit 120# .
This isn't exact but it's gives me a good idea of how much wood I'll be taking off ... (reaches for big rasp)

After reducing the thick spots first, working the belly down and tidying the tips and nocks, it eventually ended up at about 100# @ 30" which was deemed to be close enough, allowing for some subsequent sanding (I'd just finished it with a cabinet scraper), shooting in, etc.
I think seeing how I work and think was quite enlightening, as of course I didn't do all the work at once, it was up and down on the tiller umpteen times. I also did a quick demo of how to put a burr on a cabinet scraper. On the other hand I was, rather rushing and the bow was clattering around with one end resting on my vice with a strip of carpet on it. Normally I'd have clamped it and taken a little more care, working in shorter burst, but we were on a fairly tight time scale. It can get a bit busy trying to show all the processes in a four hour burst (tea and toast breaks of course!)
Once he'd gone I sneaked upstairs for a cat nap, and was out like a light.
Next day (yesterday) I ran the Yew through the bandsaw, wrote the date on it and painted the ends with PVA. The first tidy up through the bandsaw is basically taking the corners off. A half log is semicircle so that gets reduced to more of a D and a Quarter log is pretty much triangular, so the corners are taken off. Anything heavy is reduced in stages, one log was big knots along one side with only a relatively narrow clear strip and I had to take most of the knotty side off first to provide a flat face that would run flat on the bandsaw table for the next cut. I have the far end of the log supported on a roller, but even so it's about at the limit of what I can manage single handed.
The first pics shows the load of Yew with just one piece having been tidied up through the bandsaw.
The final pic shows the 4 good staves (one is barely visible against the garage floor) and a log which didn't really have anything suitable in it, (it may have had a single billet, but you really want billets as pairs, its on the habitat pile in the garden now for the bugs and beetles to enjoy).
The biggest stave may make two bows, but it's best left for now as the position of various knots may mean it's better to have one good warbow stave than two skinny marginal staves. It's the old adage "when in doubt leave it"

Visitors and a Good Chat

My old friend Roy from Med' Soc' came over for the Plum which now has a handsome black leather grip, he brought a friend David along who was interested in having a Yew ELB made.
He was also very interested in flight arrows so we had a good chat and I showed him some of my slo-mo footage of flight arrows being shot from the shooting machine. David was taking about the concept of "centre of effort" which is from sailing, it turned out we mostly agreed with each other but the semantics of describing our thoughts got in the way somewhat!
He'd tested some arrows by dropping them horizontally from a high window and wanted them ideally to fall whilst remaining horizontal or turn  slightly nose down (He can correct me if I'm wrong). I said that my corresponding test was to lob 'em up in the air underarm and I wanted them to arc over at the top of their travel and to fall nose down.
It's an interesting topic as, once the arrow leaves the bow it is falling under the influence of the acceleration due to gravity, BUT if it is shot up at 45 degrees, that angled velocity is superimposed on the fall, and until the downward velocity has increased sufficiently to overcome the upward component it still goes up.
So, is it falling relative to the air or not... or is it just falling on the way down? Do you want it to present as much resistance to downward motion as possible to slow its fall (e.g falling whilst horizontal) whilst having as little resistance as possible to forward travel? Or do you always want it lined up with the direction of travel (feel free to comment... I like comments, it shows me that people read this!).
Much of this has been addressed empirically by Clarence N Hickman using his shooting machine in the early 1900s.
I'm not going to be drawn into venturing an opinion, I'll only say that my flight arrows have their point of balance just forward of the geometric centre by about 3 or 4 % and that I've seen arrows with the balance point too far back fly most erratically turning and diving at right angles!
I use the balance point (centre of gravity) and the geometric centre as these are both easily measured.
Enough of that!
(We also had a go with the Chinese repeating crossbow of course).

Having discussed making a bow it motivated me to sort through some billets one pair looked suitable, a much fatter pair that I will also splice up had some of the dreaded blue grey discolouration (even the good pair had a little). As the billets are cleaned and reduced in dimension the wood looked better, so hopefully any bad stuff is only on the surface. It won't matter too much for a 40 pounder, but for a warbow a clean sound back is critical.
I got the billets for the 40# spliced up and have been working it down to stave that flexes. Mind, it's so long since I made a 40# ELB it's still about warbow weight! Not quite ready for the tiller yet.
Note on the pic of the billets prepared for splicing, they need a nice clean flat surface so that the sit nicely on the bandsaw to give decent straight cuts, also clean flat faces are easier to mark out.

On an unrelated topic... a story was told to me (I try not to report stuff second hand , but this has a purpose).
Someone said that they'd had no joy patching damaged bows, and they'd tried long patches but even those failed.  The other person replied that they'd seen me do it a couple of times and that I spend a lot of time getting a perfect fit, holding it up to the light and repeatedly checking until its a good fit.
The response was words to the effect of "I haven't got time to mess about doing all that!"
What??? How can you have the time to repeatedly do something badly and have it fail, but don't have the time and patience to try doing it right? Bonkers!

Awaiting Inspiration

Now't is really grabbing my attention at the mo'.
I'll do a leather grip for the Plum bow and maybe sort through my staves.
I did a little repair for an old friend this afternoon, the bow wasn't one I'd made. It was a Hickory backed Osage ELB, the repair was just a fine linen thread binding over a splinter and it didn't take long. It was good to see him and have a natter tho'.
I've got some more glass coming for crossbow limbs which I may jump onto as I also have some Maple for the core.
I did some testing of the crossbow with the rigid 'scope mount. It shot nicely with the wooden bolt at 20 yards with only about one and a half dots movement on the graticule compared with 10 yards.
I then tried the Ali' bolts and despite being 7 grains heavier they shot about 4" higher! The difference is they are slightly smaller diameter, shorter and have smaller plastic fletchings so ar more aerodynamic. The lesson is that to do any meaningful sighting up one needs well matched bolts (Yeah... I know that's obvious!)
For me the BIG disadvantage of the Ali bolts is that I can't see where they are on the target until I walk up to about 10 yards. So...
I searched the internet and found some Chinese carbon arrows that are bright yellow and 30" long so I'll get 2 bolts from each.
Six of 'em for about £11 which is cheap enough to have a play with.

It's pouring with rain here so I may end up clicking "buy" some more or writing things on my Christmas list.

Plum Bow Finished.

I got the bow finished, but it didn't seem to group well, a bit of investigation showed my hand was slipping up the grip giving an inconsistent position and effectively making the arrow sit nose up on the string. The grip needed some tweaking, this was mainly due to the upper limb having been shortened and the position of the grip notionally moved down by about and inch.
It didn't need much adjustment and it isn't a heavily sculpted grip, it's just shaped enough so the hand sits in a comfortable consistent position. The other factor is that I haven't shot for ages, so with a bit of tweaking and a few arrows every day, it's now shooting where I point it.

Plum?

After the Elder bow blew I was at a bit of a loose end and in need of a success... but something easy just didn't really appeal. I could have made a hickory and Lemonwood ELB, but then, where's the challenge in that?

So I rummaged through my staves and came across a piece of dark wood with "Cherry/Plum? 2009" written on the end. I'd often looked at this and couldn't decide quite what it was and how to deal with it, so I just ran it through the bandsaw to rough it out and go with the flow. Some comparison with some known Cherry leads me to think it's plum which is supposed to be a good bow wood. I didn't want to go mad and push it too hard so I'm going for my primitive shape at about 40-45# .
The stave has a few small knots, a crack running down the belly of one limb, a sideways kink in the other and a deal of sideways bend in the middle, there's a little deflex in an ugly place too. Other than that it's plain sailing!
I used the hot air gun to do a sideways bend at the grip. I allowed a little too much bend, expecting some spring back which didn't happen, however heating it again let it relax back to where I wanted it. The little ugly deflex was similarly taken out with heat, taking care to keep the heat off the back.

I followed a ring on the back, or at least along the centre of the back, this will get tidied further as the bow progresses. I found that I'd gone a tad tight with the bandsaw and that after following the ring I had a weak point on the upper limb about a foot down from the tip. I marked that area W for "weak" and worked the rest of the bow to match, being careful not to over-stress it on the tiller. After a good deal of work it was still a little weak so I sawed an inch off the tip, this moves the weak area nearer to the tip where the bow will be thinner anyway. Down near the fade on that limb I removed some wood to effectively move the whole limb down towards the grip... that still wasn't quite enough to remove the weak point so I took off another inch and also heat treated the weak area.
That did the trick and actually gives equal length working limbs rather than the more usual slightly shorter lower limb.
All this work didn't happen sequentially, it was a bit of work on the back, a bit of heat work, checking on the tiller and reducing the length etc all slowly moving it along.
The grip is V skinny and not very thick, so I glued on an off-cut of the same wood with the grain running the same way hoping for an almost invisible glue line. I could have used contrasting wood but I don't think it would look so primitive.

It's almost finished now and I think it will be rather handsome (assuming it doesn't go bang on the last inch of draw!)

Good Day, Bad Day

I got going on the Elder bow and made some good progress, videoing it as it progressed until ...
Well watch this:-
https://youtu.be/UlRuJkeD_5U

I decide to extract maximum fun from the broken bow by doing a destruction test on the other limb!
https://youtu.be/ua0Iwe-AP2U

Shooting the Crossbow at 3Ds

I had a great Saturday morning over at Cloth of Gold (COG) with Mick the Blacksmith and Brian.
It's the first time I've shot a crossbow at 3D targets and I hadn't done much sighting in. The previous day I'd finished making some final modifications to the prod mount, adding an extra mounting screw (I'd planned on adding this once everything else had been finalised). I tried a quick couple of shots in the garage which were a couple of inches high at 10 yards, but I left it at that for fear of messing up what was reasonably good.

At COG it was just me and Mick when we started out, the first shot being a small crocodile at about 10 yards and I put 2 bolts over the top, after that I was hitting most targets with a little vertical error but very little horizontal error. It soon became apparent that either my distance judgement, or my previous calibration was a bit out at longer ranges.
After a few shots I let Mick try it at about 30 yards. I shot first to check the sight was about right, he put his shot about an inch from mine and closer to the inner kill. I was pleased with that as it shows the crossbow is pretty solid and consistent. Mick actually made a fine shot with his bow too, so I took a pic. (top left)
It was just after this target that Brian caught up and joined us.

 Basically out to about 30 yards, my sight marks and estimation were reasonable and I could hardly miss as long as I set the sights slightly short, it almost seemed too easy! Beyond that was trickier and on the longer shots I tended to shoot over, if I put one over, a slight adjustment would put the second on target.

We shot 18 targets going round once shooting from both A and B sets of pegs, this allowed us to get our shooting done in time for a ham sandwich, bowl of chips and a pint at the pub.

Unbeknown to me Brian took some pics of me cocking the bow and shooting which he sent to me, thanks Brian :-)

I'll probably leave the crossbow for now although there is plenty I could do to fine tune the performance, mostly by improving the sighting and actually making some bolts that are visible! The bolts are cheap ones with anodised aluminium shafts which are a pinkish red colour, now you'd think they'd show up, but I have a slight red/green deficiency (like many men) and in a dark woodland they don't show up in flight. White or yellow bolts would be much better, this mainly matters if you miss with the first shot as you'll know if you've missed high or low. On one long shot I simply never saw the bolts despite having both eyes open. As it happens they were all high, but I couldn't tell.
Update:- I reviewed the sight marks (on the Monday) on my adjustable scope mount by clamping it in a workmate with the scope lined up at a distant reference point. As I adjusted the mount I could see the crosshairs didn't move until I got beyond the 20 yard mark due to slop/backlash in the mechanism. Up to about 40 yards the graticule in the scope was enough to adjust for the elevation. So a fixed mount would probably be more reliable sighed up at say 30 yards, the graticule would then be used for range compensation. Sometimes simple is best!
I probably won't shoot the crossbow at an open shoot but it was fun to have a go at 3Ds shooting with friends. There are a couple of reasons why I won't shoot it much, but it's mostly that I feel it doesn't have the same intimate connection with the archer that a self wood bow has and that it would be easy to get lured into chasing perfect scores. I feel it becomes more of a distance estimation test and about scoring tactics rather than pure fun.
I tend to shun competition as it's easy to spoil the enjoyment.
Indeed on Facebook there was recently someone who said that the thought taking kneeling shots with a crossbow was cheating, despite the NFAS rules specifically saying using any part of your body for support was ok.
They said, if you take the rules literally then it's within the rules! I did ask what other way you could take the rules? The irony is that the person involved actually used a strap ,which IS arguably against the rules! (Which I quote below)
"The archer must not use a rest of any description which provides an additional point of support for the bow whilst shooting. This does not include the archers own body".
That little incident nicely sums up why I don't shoot competitively.

Anyhow, why did I make it? For the fun of the engineering challenge, to improve my skills and understanding, so I could see what it was like to shoot, so I could compare the performance against my usual bow, and so that I'd have an appreciation of shooting a higher velocity bow.

For now I'm working on the Elder stave with the Willow levers, but I reserve the right to tinker with the crossbow if I get the urge!

Quick Arrow Puller and a Goody Bag

The bolts from the crossbow are damn near impossible to pull out of my target if they hit an area that hasn't been shot up a bit.
So I sketched a quick dirty arrow puller, and made a try out from scraps I had lying around.
It basically worked first time but needed a bit of fiddling to get the lever lengths right.
The important bit is the rubber lined groove to grip the bolt without damaging it.

I had a look for pics on the interweb to see if there were any good designs out there, some were over complex and others had more than one part (you can guarantee to lose one bit). I went for the generic basic design, but kept it simple by having a single sloppy joint where the arms meet rather than a fancy hinge with 2 degrees of movement.
It needs some movement to allow the device to be fitted round the bolt/arrow shaft.

Hopefully the pics, show how it works. The important thing is to pull for a short stroke and then re-position the clamp down the shaft, as one very long pull could bend or damage the shaft (you can make up your own jokes there! ).

Post just  arrived with some goodies from my Brother, some slitting saws which will go on my mill, and a couple of locks from old shotguns for me to study.

Sighting In Some More

I took the crossbow over to Now Strike Archery fairly early and had the ground all to myself in glorious sunshine
It's impressively fast and flat out to 30 yards with only slight elevation needed on my scope mount.
As the range increases the downward component of velocity increased as the arrow accelerates downwards due to gravity, making the trajectory more curved and the bolts were briefly visible in flight. The changes to the scope mount were much less than with the Boo/Yew prods, so much so that I got it sighted out to 60 yards.
I didn't spend too much time trying for tight groups, I was just trying to get the elevation about right for each 10 yard increment, shooting about 6 bolts at each range.
What surprised and confused me was that when I sat on the rear sill of the car (with the hatchback open) and leaned against the rear pillar to get a solid shooting position I always shot high!??
I actually put two shots over the boss when trying to shoot like that, but I found them both.
Discussing this with my brother later in the day, it turns out that this is a recognised effect with spring type air rifles which have a similar slow action with a moving mass (apparently they are bad at shaking up scopes too). Trying to hold too solid increases the effect of the recoil (and possibly the reaction to a fairly heavy trigger pressure), whereas holding more lightly allows the bow (or rifle) to find it's own balance/stability due to its inertia. (dunno if that makes sense)
When I stood and shot in a more relaxed manner without gripping the crossbow so hard, I shot much better.
With all the shots the horizontal dispersal was minimal, it was only the vertical variation that gave any trouble.

All in all a good session, the only minor problem being that I forgot my arrow puller, and it was hell's own job pulling the bolts from the target, so much so that I felt my back complaining, so I quit while I was ahead.

Tomorrow I can review the marks on the wheel of my adjustable scope mount and compare with theoretical figures, making minor adjustments and engraving decent marks onto the wheel.

The only outstanding question was the draw weight.
So, in the afternoon, I got the bow bolted down at floor level and drew it via a long double hook of 6mm steel bar with the spring scale on the end.
Turns out it's 108# which is about what I expected.
I took a quick (rather shaky) video showing the arrangement used for measuring draw weight.
https://youtu.be/1JVTiy5BKXk

Tarting Up and Sighting In

I've had a cold all week, (just about gone now) but manged to do some tarting up of the crossbow prod mount yesterday, adding some nice curves, done on the milling machine as a series of overlapping holes and cleaned up on the belt sander.

I got the tele' sight back on it this afternoon and did some sighting up. First thing I noticed, it was shooting high at 10 yards, being faster than the previous wood/boo prods, and I had to modify the adjustable mount to elevate it a tad.
I got that sorted and was about to quit but I realised I had good opportunity to sight it at 20 yards diagonally across the garden as the missus was out ;-) and the cat was asleep indoors.
I adjusted the sight a bit by guess work and the first bolt was scarily close to the top of the boss, whoop! I set it back a bit and the next shot hit the 2" square of paper I was aiming at, I quit while I was ahead.
My son was around so he had a try out at 10 yards, it was tricky for him to hold, as he has balance problems being in a wheelchair. The feedback I got confirmed that the trigger pull was rather heavy, so that will need some work.

The whole thing is an ongoing project, an maybe I'll start on a decent stock for it some time (I have the wood), as at the moment the comb isn't high enough to be comfortable with the tele' sight and it's ugly!

It feels very smooth to cock, heavy early on, but doesn't seem to get stupidly heavy as you pull back. When shot, it rings a bit and there's some recoil, but I think the string is over twisted, making it a tad springy and the brace height needs finalising. A lower brace gives a longer power stroke but can put extra stress on the limbs. I may even try making string buffers (I'm thinking rubber bungs on ali' pillars).
Anyhow, plenty to tinker with, but trigger pull first, then sight it up at some longer ranges (maybe Sunday) and eventually some field shooting.

Finished Crossbow Prod Mount

The mount is finished and it's holding the prod very securely, there is sheet rubber beneath the limbs and elsewhere too. I've removed the shim of 3 ply from under the stock to get the string sitting just a whisker above the track. (see pic)

I think it looks a tad Brutalist with maybe a hint of Art Deco. I might round some corners and remove some excess metal later to improve the aesthetics.
With the masking tape removed, the limbs look rather handsome with the Maple showing through the clear glass.

I took a quick full draw shot...
I'm not entirely happy with it as it is working hardest mid limb, but the outers are flexing. I could maybe take a few mm off the underside of the last 6", tricky to see with out a decent comparison with the unstrung shape.
The close up of the nock shows the construction. There is a wedge of maple adding thickness to the wooden core, a horn piece is overlaid over the glass backing, this is then recessed slightly and bound with carbon fibre/epoxy to minimise the risk of the string splitting down the nock. These are lessons leaned from earlier prods.

I haven't actually measured the poundage at full draw (it's difficult to set it up for such a measurement) and measuring it won't actually effect the reality! It's relatively comfortable to draw, so my guess is about 100# or a tad over, it certainly seems to have decent speed vs draw weight. (255 fps at last measurement)
I'll have to try it through the chrono' again later, as the improved rigidity may have given it another couple of fps, mind I might not get round to it as I have a cold and may retire to my bed!

Update:- Just tested it 258.5 fps :-)
And here's the unstrung pic for comparison.
I've combined the 2 pics here:-

A Waiting Game

I've done a lot of work on the crossbow prod mounting and it will be much more solid when finished, the limbs won't be able to lift at all at the tips. I've had one more test shot at a fractionally lower brace and it was about 1.5 fps faster which is a refreshing change from the natural material prods which lost speed with each shot.
Once the mounting is finished, I've made a new string and optimised the brace height it should be pretty respectable... I recently saw a 175# crossbow advertised as having 145 fps which makes mine look rather good as it's prob only about 100-120# tops.
I've had to order a variety of screws for the prod mount and while I'm waiting for those, I've taken a little more off the Elder primitive. I've also had a chuck of wood with a nice natural curve which I'll use to make short levers for the Elder drying out on a radiator, still not sure if it's Ash or Willow, but once I start working with it, I'll probably find out!
That's about it really, done some pruning and tidying in the garden and generally been enjoying the fine weather.

Done some more and cut the splice for the levers, here's a pic of one dry assembled.