Archer Automaton Extra Details

I've been asked for more detail about the Archer Automaton, so I've done a video here:-
https://www.youtube.com/watch?v=YIuBXjywir0&feature=youtu.be

Here are a few pics too showing elbow, bow hand and shoulder joints.
Note it's not supposed to be a nicely finished piece, just a proof of concept model to see how it could work.

Tail End of 2019

The best news this year is that I became a Grandad on the 23rd of December! :-)

My Daughter produced identical twin girls which made for a rather odd Christmas day and will doubtless keep us all busy next year.
As they are identical twins I've just shown one of 'em ;-)


I've had a bit of a break from bows as I've been modifying my Mini Mill (a Clarke CMD10, which is the same as a Sieg X1) to make it belt drive which should make it smoother and quieter. The pic shows the small stepped motor pulley standing on top of the big one which is still work in progress, centre hole being bored with a boring bar.
I found a nice article on the web where a guy showed how he'd done it, I pretty much copied what he did with slightly changed drive ratios and a few other details.
Once that's done I'll finish making the steel quick change tool post (QCTP) for the lathe. I bought a cheap Ali' one which works well for light work but has quite a bit of flex for any heavier work, bearing in mind by "heavy" I mean relative to size of the little lathe. Being fair to the lathe, it is doing a stalwart job and is even managing to turn 4" diameter Aluminium billet for the V pulleys for the mini mill belt drive.
I'm waiting for delivery of a 3/8" BSF tap at the moment so I can tap an alternative toolpost mounting hole on the compound slide of the lathe to enable the turning of the largest diameter V pulley.

I'll have a bit of a clean up ready for Thursday when my mate JT will be over for some bow making fun... currently working on the Boo backed Yew warbow.
Boo backing has been a bit of a theme over the past year, I made a series of 4 boo backed yew 50# flight bows, taking the best of them to a comp' and refurbishing the other two as gifts. I made a heavy boo Yew primitive and a boo yew warbow too, plus the usual sprinkling of primitives including a Wych Elm one.

Seasonal Break

I'll be a bit quiet over the holiday period as we are expecting a busy time due to the imminent arrival of identical twins courtesy of my daughter. Fingers crossed all goes well and I'll be a granddad!


I'm also busy doing some mechanical work converting my mini mill to belt drive and making a steel quick change tool post for the lathe (the cheapo Ali one works quite well but has a lot of flex).
Pic shows V pulleys for the motor (it will have 2 speeds) being turned for the belt drive. Good fun working out how to do it :-)

BTW, I found some nice stainless steel rings from http://www.gwr-fasteners.co.uk/
I bought a couple of 8mm x 40mm diameter to replace my broken string adjuster. The 8mm thickness works out to be about an inch adjustment for each turn of the string through the ring.

Anyway, seasons greetings to one and all, and I expect I'll post a round up of the year plus some news in a week or so.













Mr Hare says happy Christmas!

Updatey Update Post

JT came round and he did a good deal of work on the bow under my watchful eye. There was the usual panic as the spoke shave or plane dug in and started to tear, but careful use and resorting to the rasp kept things under control.
The bow progressed nicely to about 100# at 20" at a modest brace which is pretty much the amount of work I'd hoped for.
The oddest occurrence was the magic aluminium string adjusting ring breaking whilst try to brace it for the first time! I wouldn't have believed it, had I not witnessed it myself.
Update:- I got an E-mail from my mate Mick the Blacksmith, he said :-

The break is a typical stress fracture and probably started from a small crack sometime ago.
In industry when they test the tensile strength of something by pulling it apart, the fracture is the same as you have on your string thingy.

We took some good video at three stages of the progress.
https://www.youtube.com/watch?v=dvSI_onb42o

Previous day my mate Rob came over with some stuff to do. He had a half log of Wych Elm which we ran through the bandsaw laid out as a primitive. The stave has a huge amount of reflex so I though a wide flat design would have less stress than a longbow. He also had a warbow that had over 4" of set... it was pretty obvious why... the bow was over 1mm thinner at the arrow pass than it was for about a foot either side of it! It was obvious to see and to feel, dunno how someone can make a bow like that (he'd paid good money for it). He felt it was no good, so it was worth risking drastic action.
We got the bow strapped down mid limb on one limb (back down). We'd protected the back with multiple layers of masking tape and lightly clamped side cheeks to the bow to keep the heat on the belly. About 5 mins with the hot air gun and we pulled the bow down straight, strapped it down and heat treated the belly over the thin area. After lunch, we had a look and found a series of short transverse cracks had opened up. I recon these were fine chrysals that weren't obvious before, but opened up as the bow was heated and straightened. What to do? Well we rasped out that area of the belly and glued on a patch of heat treat Yew which will allow the bow to be re-tillered with the grip at the correct thickness. Rob left with patch all strapped up (it takes overnight for the glue to cure).
While he was over here we glued some horn tip overlays onto a Yew kids bow he's made for his son.
Heard back from Rob, he's re-shaped the belly where the patch is, and done a bit of scraping here and there to take off some thick areas. The set is now just 3/4" and the draw weight is up from 112# to about 150# ! The tiller looks much better now. Result!

Quick Update Post

The Boo/Yew that I've been helping my mate JT to make is ready for some serious work on Thursday, hopefully getting it to low brace and drawing to 20" or more inches... maybe even 26"-28".
Last week JT posted some progress on Facebook (as he does after most our "blokes in a shed" Thursday sessions) but was beset by smart arse comments from people who should know better, bearing in mind they know I'm helping/supervising (and I'm not an idiot). One comment was to the effect that interpolating draw weight from a partly finished bow is pointless and he'd be lucky to get 50# from it. Well to answer the first point, it has been shown to be both reasonably accurate and useful. E.G the bow in it's current state interpolates to about 200# @ 32", well this shows we have plenty of wood and no need to worry about making the target 120-130# draw weight.
If you want more info' read this post:-
https://bowyersdiary.blogspot.com/2017/11/long-string-on-tiller.html
The second point? Well time will tell, but I'd be willing to wager £50 that it will end up between 120# and 130# at the target draw length of 31" (all proceeds to charity, if anyone fancies taking the bet!)
There's an unwritten rule that people would do well to abide by... don't offer critique unless asked, and if you really must, at least make sure you are fully aware of all the details. I also try to go by the mantra of "If you can't say something good, don't say anything at all, unless invited".

Anyhow prior to the next instalment which will hopefully be on Thursday, here's the video we took last week, which shows it flexing quite nicely at a very useful draw weight of about 90#-100#...it will be pulled harder once a little more has been done to adjust the width, fill a small knot and round off some edges.
I could have posted this on the Facebook thread, but it wasn't my thread and I didn't want to get sucked into it.
https://www.youtube.com/watch?v=YbdlcsFww5Q&t=7s

Bonus update from yesterday (11/12/19). The bow testing rig had it's first real test on a 125# bow:-
https://www.youtube.com/watch?v=2HRlpSGfNv0

More Belt Sander Fettling

For a while now both the belt sander and the lathe have needed a flick to get them started. I suspected the run capacitor in both cases. Both are small AC induction motors that only have a single capacitor (bigger motors have a separate big start capacitor and a run capacitor). It's difficult to test a capacitor without a specialist meter, some convoluted and cunning measurement* or testing by substitution (or similar) on a live machine.
I happened to have a spare 6uF capacitor but was reluctant to try wiring it in or dabbing it across the terminals and switching on. The lathe motor had been getting increasingly noisy and I'd replaced the bearings recently so I wanted to fix it.
The lathe capacitor is 8uF and I thought if I put the 6uF across that in parallel it would give me an indication if the old one was shagged. I held the cap' in place with one hand with the two wires touching the appropriate terminals (not easy) and switched the lathe on with the other hand... It purred into life, great! That proved that the capacitor was the problem.

While I was on a roll I dismantled the belt sander to see what size cap' was in there so I could order a new one for that whilst I was at it. It was 6uF, ha! (old one is pictured). That's what my brand new spare was, I fitted that and it now starts without a flick. Whilst the belt sander was apart I noticed a lot of fibrous dust had collected in the bottom of the belt guard/case and it was covering the lower half of the motor pulley.
I thought a small hole in the bottom of the guard would be a good idea so that the dust would fall out or could be picked out. A couple of minutes with tin snips, hammer and file made a nice small hole which can't trap a British Standard Finger, but should do the job (indicated by yellow arrow in pic). Note, the underside of the sand belt doesn't have a guard... that's because it is a right pain to remove one when changing belts... (anyone who thinks that this is a hazard should consider that it's no more of a hazard than the top of the belt!)
I ordered a couple of capacitors from Ebay an 8uF and a 9uF just in case a bit of extra oomph was needed. It's not a simple case of more is better and the manufacturers recommended size (+/-10%) should be used. However capacitors are notoriously poor tolerance components so I thought going up to 9uF if necessary should be fine.

While I'm waiting for those to arrive I might add the old tired 6uF in parallel to the old tired 8uF and see how that runs.
I'm keen to get the lathe to start up when switched on, as it almost caused a fire last week!... The switch had been knocked to "on", the lathe cover was over it and the motor sat there stalled humming quietly... I'd noticed the hum and thought it was the central heating pump. It wasn't until my mate JT, who was there, said can you smell something? (Other than my usual farting) that I investigated further.
The motor was too hot to touch and the film of oil and dirt on it was smoking lightly! It was this incident that led to me dismantling the motor and replacing the bearings. Getting it starting correctly should avoid a repetition. Note:- The switch is easily knocked because it is positioned to be accessible for emergency switch off. Of course a fancy latching switch with big red button would do the trick and be less likely to get switched... but IMO the solution is to cure the fault rather than just add more complexity (and cost). If the lathe had actually switched on, it would have been obvious.

I've also been doing more to the bow weighing rig, adding some angle ali' at either end which will provide a way of clamping it to a table. It also adds some extra rigidity.

* For those who are interested I suppose you could measure its capacitance by charging it up to a known voltage and plot how it discharges through a known resistance over time using a digital voltmeter and work it out from there.

Yew Boo Glue Up

My mate JT has been over off and on over the last few weeks and we've been working down a marginal Yew stave, the sapwood was suspect so that came off and it's been gradually worked down as the belly for a boo backed warbow/roving/flight bow.
It's been tricky due to the limitations of the wood, knots, encroaching sapwood etc.
Don't quite know how it will perform or what it will be yet, as it's rather short. Mind it would have been 6" shorter if we hadn't cut out a big knot that ran at a shallow angle through one tip. We actually milled it out as a slot right through the limb on my mini mill (Clarke CMD10). I could have chiseled it out, but it was fun to try a different approach and there was less likelihood of splitting the wood as it was knotty. We fitted a plug about 3" long. The plug being slightly wedge shaped such that, once the Boo back was on it could't possibly pop out (see first pic)

The stave had a fair amount of deflex, and it was glued up on a former with about 1" of reflex. We got it glued up yesterday with clamps and rubber strapping in between for extra belt and braces squeezeosity.

Taking the clamps off this morning the stave sprang back up about 1/2" at the grip making it pretty much straight and putting some nice pre-tension into the Boo backing.
The stave still has some undulations and will have a bit more character than a laminate made up from machined timber. We could have spent more time getting it pre-tapered and even, but our sessions are limited for time and we couldn't resist the temptation of getting the glue up done.
It's that old balance between perfection and pragmatism. :-)

It will be interesting to see how it feels once cleaned up and tried on the tiller... that will have to wait until JT's next vist.

Final pic shows the bow testing rig having a tentative try out with my filed bow. The rig isn't fully finished yet, but it seems like it will work well.

Bow Weighing Rig

I'm making this portable rig for someone to replace a somewhat heavy and agricultural one.
It gives me an excuse to turn some bits on the lathe and bash some metal.
I bought the crane scale off E-bay for about £19, I've made a nice curved piece to hook onto the bow string and modified the scale slightly, removing some of the bulky case to allow the hook to be fitted better.
I sawed off some of the excess case and used the offcuts to patch the resulting holes, which I then painted with some Humbrol enamel, which gave a remarkably good match.

The scale is rather nice inside, a shaped plate of aluminium has strain gauges mounted to it (these are covered with epoxy) they are wired to the circuit board which has a surface integrated circuit (amplifier) and another mounted directly on the board, potted in epoxy (display driver)? The push buttons are nice discrete switches with good feel (rather than unreliable membrane switches), they sit behind a thin membrane/label which keeps the muck out and protects the display.
It was worth taking it to pieces as I found the internal screws that hold one end of the plate to the case were loose and there was small split pin inside! (it's part of the kit of bits, shackle, hook etc that comes with the scale)
The spine of the rig will be a length of aluminium extrusion which was left over when we had solar panels fitted. The clamp to hold the bow is made of layers of ply, it slides in the extrusion and a simple loop of bungee cord with a nice leather tab holds the bow firmly in position against the larger fixed plywood block. The bungee hooks over a knob turned from lignum vitae (I bought a chunk of lignum off E-bay just for the fun of turning it).
 The winch is also made of plywood glued up and turned on the lathe, it pivots on a turned steel shaft and the handle is turned wood mounted on an aluminium crank. I pretty much copied the dimensions from the original, whilst improving the detail.
I've laid the parts roughly in position to show how it goes together. One nice feature is the measuring tape which slides nicely in a channel along the aluminium extrusion, this will be attached to the sliding block which presses against the back of the bow, thus giving draw length measured to the back.

I'll probably get the rig finished before picking up the next stave, which I expect will be a Pacific Yew Warbow for my mate Rob, not the same Rob who had the Yew primitive...

Yew PV Finished

I've got the bow finished and taken some video of it being shot.
It's surprisingly difficult to get a good image from the video due to camera angle, lighting and the movement of the bow. In the still taken from video, the upper limb looks much fatter than the lower due to the change in contrast despite the green fabric hanging up to cut some of the back light from the sky.
It shoots very crisply with the arrows waggling a fair bit over the 10 yards, I may ease off the arrow pass a tad, mind the arrows are 35-40 spine and the bow is 50#

Video here:-
https://www.youtube.com/watch?v=_C3nxhEEHbE

Multiple Projects

I seem to have swung from nothing much to 4 things on the go!
The Yew primitive needed steam bending to get rid of the side ways bend before it can go on the tiller. First session didn't seem to relax the wood much so I immediately refilled the steamer and have it more time. I pulled it beyond straight and over night it did recover to some extent but was still slightly over corrected. Another steaming allowed it relax back a tad and it looks good now.

While I was waiting for the steaming and allowing time for it to cool I did some roughing out of Rob's Pacific Yew stave, a very nice piece with lovely consistent thin sapwood which won't need any reducing. That will be ready for first try on the tiller soon.

Meanwhile my Pacific Yew stave arrived, not such a nice piece and a less experienced bowyer would have found it very challenging. There was a good deal of deflex and sideways bend, there were muscular ripples running diagonally across the back which told tales of internal stress. I allowed some extra width when doing the first rough out, and as I took a little off the side the thin slice curved itself down towards the belly which is rather unusual.
As I took some off the belly it revealed some nasty worrying black manky stuff where there had been damage as it grew. This will probably be a bow for me and at about 90# maximum so there is still enough good wood, I was a bit concerned that the manky stuff went deep and continued along the whole stave, but it seems ok. The wood was also a bit brittle in parts splitting off too easily for peace of mind. Anyone who had tried to lay a bow out and cut it in one go would have been in trouble... mind there is still plenty of time for me to screw up, but then I like a challenge.

The above is a good illustration of why the buyer needs to beware even when buying from a reputable source and having viewed a video of the stave... no one knows what lurks deep inside the wood.
I blame the fact that it was ordered on Halloween (cue spooky music).

I've also been doing some to the portable bow weighing rig, but I'll post pics of that when it's all finished.

Update:- First video of the Yew Primitive on the tiller here.
https://youtu.be/8Vso6D7dQ_k

Bouncing Back

After the collapsing step ladder incident I didn't feel too bad, but the next day it kicked in and I felt rotten. It's all settled down now, but I'm still a tad sore, so when I went to the Society of Finsbury Archers Baron Camoys shoot at Stonor Park (Oxfordshire) I just shot over the morning.
It was a great shoot, in a lovely setting with a large turnout (50 plus?) and great company. I enjoyed a good natter and a bite at lunchtime before driving home. The shoot itself was roving marks with many of the shots being across the valley. Just before lunch we did the speed shoot, as many arrows as you can get off in 30 seconds at a mark set at about 100 paces. I loosed 6 arrows with 3 of them scoring which was pretty good, one guy managed 7 with 5 scoring which is impressive.
Whilst there I handed back the bow that had needed some fiddling and fetting and collected a lovely Pacific Yew stave from Rob which he wants turning into a 130-140# warbow.
Many thanks to Emma and "Dodge" Erry for the excellent organsiation.

The decision to quit at lunch was a good one as I arrived home in good time, pleasantly tired and ready for my Sunday roast.

I've picked up one of the skinny Yew staves and started work on a primitive for a guy... (another Rob), he'd had his name down for a bow for ages, and this seemed like the right stave to give it a go.
I no longer have a real list of orders as I tend to only make them for people I know (or who visit) or if some interesting wood turns up or an
Anyhow the primitive a bit odd as the stave seems much skinnier at one end with not much heartwood and it has some sideways bend and a nice burr knot on one limb, the target weight is only 40-45# @28" so it should be fine and have some interesting character. Hopefully I'll get it on the tiller for first flex today or tomorrow. I might trim down the big Yew stave too just to get a feel of it, and to see if I can cut off that corner knot, it might even yield a useful off-cut for a belly lamination.
I'd better get on with it rather than sitting here ...ha... my enthusiasm is back :-)

interesting bow is wanted. I only make 'em when I want to rather than when I feel I should... doing it because you "ought to" is a mistake IMO.

More on Sawing/Roughing Out

"Explain more" Was ticked on the last post...

I'll expand a bit about sawing out a log, it requires more care and thought than is obvious. At it's simplest you can just lie something straight along the log, mark with chalk either side and saw it (or run a straight string line and work from that). I have a length of very light weight steel U section the sort of thing that is used by builders putting up partitions or stud walls, its 1.5" wide and I found it in a skip. (see pic). Using it for a first rough out allows plenty of width. If you lay out that first cut out carefully you can remove some knots or place them in the centre of the stave.
The pic top left shows how I laid out the stave over to one edge to remove as much of the big black knot as possible. The pic below it shows the two sides opened out like a book and you'll see there is still a waggle of grain showing but the manky part of the knot is no longer in the stave.
There are still more things to consider as it's easy to mark a straight line on a curved surface and end up with a curve. I was lucky with these staves as they were pretty flat and straight, but with a log that is deflexed, reflexed or has a sideways bend it's easy to mess up when you run it through the bandsaw.
Putting it through the bandsaw is tricky too, I have a roller support behind the saw to support the end of the stave which helps. If it can be run through in a clean straight line with no twist (even if it's just on one of the first cuts) that provides a nice flat surface to rest on the saw table for subsequent cuts. (and for ease of marking out later). It's easy to rotate the stave slightly as it goes through, I try to hold it and guide it as one would a snooker cue using a clean straight action, I try to avoid too much re-positioning of my hands.

 Note, these first cuts are all straight and parallel, (so it resembles a length of 2x2) just to remove the excess wood and and allow me to see what's there before marking out the actual bow, it also allows some margin of error for the wood to move as its internal stresses get released. This is the state that most people will recognise as a stave, not being aware of the work that's already gone into getting it to this stage.

This is fine for a straight stave that can can be roughed out straight and Yew which is tolerant of some grain run out...
On a character stave or a less forgiving wood the cutting is very much by feel and eye. A process of successive approximation and being sympathetic to the grain flow of the wood. E.G See pic on the right. two wonky staves from the same batch of timber, these will need some careful reducing and some steam bending to get decent staves.

Having cut the two sides, it's much easier to handle it and lay out a line for the thickness of the bow. The quality and thickness of the sapwood is now more visible and some thickness allowance can be made for reducing the sapwood if necessary. At this stave I still tend to mark it out parallel. This may seem odd, but allows for error and also means any off-cuts are more likely to be usable. Sometimes cutting some of the final taper can be handy to give two tapered off-cuts which may work as billets. It's all a matter of studying the wood and maximising what you can get out of it sensibly without jeopardising the main stave... always best to have one good stave than two useless ones!
The next step will be to remove the bark and some sapwood where it's been gnarled up with a chainsaw and general rough handling. The wood may get another month or so to season and settle, I think it's a mistake to rush at it as wood may keep moving... some say it needs a year per inch of thickness, so bearing in mind there was a lot more thickness there before it was reduced a bit more time won't do any harm.
Oh bugger!
Just shaken myself up... I was up on the step ladder putting the staves back on the top shelf when the damn thing splayed open and I crashed to the ground. I'm ok, but grazed my elbow, knees, bruised my thigh and my arse/lower back is sore. Took me a while to get up off the floor.. expect I'll be stiff as a board tomorrow. At least nothings broken and I didn't hit my head.
The step ladder is an A shape, but the horizontal brace can be detached to allow it to fold up/extend. Normally that brace stays in place even when the ladder is folded and stored... it must have popped off, and I hadn't checked it... I normally do. By sod's law the rubber feet that I had replaced a few years back have worn through leaving bare steel which skidded on the concrete floor.
Every man is his own safety officer...

Next job, refurbish the step ladder or buy a new one. Mind I can't find one that has quite the same handy configuration.

A Pleasant Surprise!

I've been thinking about warbows and flight bows whilst bemoaning my lack of seasoned Yew.
The oldest Yew I thought I had on the shelves is April 2019 so maybe I could have a look at at and rough it down a bit.
I'd been out in the garage in the morning tinkering with the portable bow weighing rig which has been fun as it's given me an excuse to use the lathe and mini-milling machine, but it was bloody cold (had our first frost last night).
Anyhow in the afternoon I put on an old fleece and went out to have a play. I got up on the step ladder and took down a couple of huge great staves (sort of roughed half logs) which were the timber I had in mind... It said "Oct" on it ... that can't be right it's October now??
Ah! Oct 2018! Woo its certainly ready for reducing and making a start on, great!
This shows why I always write a date on the timber... it's so easy to loose track otherwise.

I put a coarse blade onto the bandsaw and donned my facemask (I'm much more assiduous in wearing it these days).
The first bit was the sort of size that a novice wood think would make two bows, but bearing in mind I'm thinking warbow, I knew there would be just one good stave with maybe a sliver of heartwood that might come in handy.
The second piece was lovely, and by taking off the two edges to give nice flat faces I was able to get one good stave and a nice thick full length heartwood stave too.

The last pic shows how the tension in the wood has made it shift once its sawn along its length... which is why it's prudent to reduce timber in stages.

Not Much to Report

I've been tinkering on my lathe making fittings for a bow weight measuring rig and refurbishing/improving an existing one for the ILAA.
I've bought a nice crane scale for it which weighs up to 300kg, a tad overkill but it's got a nice big display and is rugged. There seems to be a gap between 40-50kg and then 300kg which means if you want to weigh warbows with a digital scale you need the 300kg one.

I've also been busy growing a 'tache for "Movember"... it's very tiring. It gives me a laugh every time I look in the mirror.. I'll prob' end up looking like Blakey from "on the buses" :-)
We've had visitors the last few days and I'm generally lacking inspiration on the bow front. I don't like to force the issue.
I expect I'll pick something up soon when the mood takes me.

Tweaking a Bow

Some time back I was asked to make a pair of bows for a couple (Catherine and Brian), they wanted laminated bows with a good cast for roving at relatively low weights 35# and 50# respectively.
Well laminates aren't my thing and I wasn't keen to do it, but this couple do a lot to promote longbow archery, so I wanted to find a way to do it without having to buy fancy exotic timber. I also knew that Boo/Yew was one of the finest combinations, but for some bonkers reason Brian didn't really want a Yew belly.
A good solution dawned on me, I'd rework two of the 50# prototype flight bows I made earlier in the year and present them the bows as a gift. The 35# was Boo/Yew/Ipe and the 50# Boo/Yew, this avoided too much work for me and any embarrassment over what to charge and the fact that his bow has a Yew belly :-).
I tarted up the bows with nice leather grips, hers being red Rolls Royce upholstery leather with a mother of pearl arrow plate. I padded out the flight strings to accept regular arrows.
The bows were handed over at a rove and they were astounded by the distances they were shooting. Catherine found she had to shoot alongside the heavy bows rather than moving forward with the lighter bows, even then she was still over-shooting the marks! I suspect her bow cold probably win a 35# longbow flight contest as it shot only about 5-10 yards less than the 50#
The next week I received a very nice letter of thanks.

However, on Thursday Brian's bow reappeared in the hands of my mate JT having been sent back by Brian for a check up as he'd found it popping the string off when bracing it.
I strung it and could immediately see it had shifted a bit and was trying to bend sideways and the lower limb which had more reflex than the upper looked too strong. It dawned on me that the bow had only been shot by me maybe half a dozen times which would account for some settling.
By pushing the string loop across in the nock a tad it stayed strung ok, but I could see a slight sideways bend. A few good scrapes along the strong side of the belly eased off the excess strength and removed the tendency to bend. A bow will tend to bend towards the weak side, thus the opposite (strong) side need easing off. I scraped the "corner" between side and belly on the strong side.
It looked better, but I thought the brace height (BH) looked a bit low too, it was only about 5" and the string appeared to have almost no twist in it. Twisting it up a bit raised the BH to 5 1/2" and I decided to add the BH measurement to the writing on the back of the bow (5 1/2 - 6").
It was looking really good now and I decided to get some arrows shot through it to help it settle down...
WOW! It really smacked out the arrows (my regular field arrows) and they stuck in the target dead true in a perfectly vertical line with barely a finger width between each one. I couldn't help thinking it would make a great field bow being so fast, yet shooting clean and true.
I'll shoot it in some more and return it at the next roving shoot, being sure to demonstrate how to check the alignment, string loop position and brace height.

Out of interest, while the bow was at it's lower brace I had applied a slight sideways force and the bow did indeed give a slightly alarming kick as it twisted sideways and flicked the string off round to the back.

Bow Scale Peak Hold

I've been roped into decorating the lobby, blimey it was only done about 15 years ago ;-) ...

So, I was looking for a quick little project that I could do whilst waiting for walls to dry etc.
A peak hold needle for my bow scale is something I've been thinking about for ages and it gave me an excuse to play about on my lathe.
It's turned from brass in two parts with an M4 thread, the actual needle is cut out of some tin plate (an old olive oil can ... I knew it would be useful!) and glued onto the brass with epoxy. The vital friction is supplied by a cardboard washer, the two parts are nipped up to give the right degree of friction and a spot of superglue is applied to the thread.
The threaded hole goes right through (unlike in the sketch) and the needle has a hole in it so I can see the thread to apply a spot of glue.
The sketch was just a rough guide and some dimensions needed changing once it was tried on the scale... notably the thickness of the brass section which sits inside... when I first measured (having drilled the hole in the clear plastic) I forgot to subtract the thickness of the plastic, so its, 7mm not 10mm

The needle is coloured black with a felt pen... it has a little tab bent down towards the scales o that the red needle pushes it round as it advances.

It works a treat, I'd like to knurl the knob but I've no way of conveniently holding it tight enough in the lathe chuck without risking damaging the M4 thread... if it ain't bust, don't fix it.
It will be handy for doing force draw curves and measuring the draw weight of the crossbow which is very tricky as it's difficult to draw it and see the scale.
Notem the scale has the Kg markings painted over and bold lines added every 10 pounds, with big spots every 50 pounds, this helps it show up in video footage.

Update:- I had to modify the red needle a bit as the forked back end was also moving mypeak hold needle! I just trimmed a couple of mm off the forked end.
I then set up to measure the crossbow draw weight. I was a tad surprised to find it was only 73#, but I s'pose the performance is pretty good considering. I may increase the draw length a little more taking it up to about 80# which should give the speed a nice boost, but I don't want to over do it as it is perfoming nicely now and the weight is very manageable.

Sighting the Crossbow

I did some more tinkering trying get the scope mounting more solid. I milled a piece 140mm length of 4mm aluminium alloy plate to a taper and put that between the scope rail and the wooden latch cover of the crossbow. That is much more solid than just shimming one end of the rail.
I checked the sighting at 10 yards and confirmed it was pretty good vertically (aiming 3 dots low).

While my better half was out ;-) I set up in the garden, the target boss placed in the doorway of the garage and I put my workmate and a chair near the summer house giving a 20 yard range.

Resting the fore-end on a tightly rolled old duvet and just holding the pistol grip of the crossbow in my right hand and the left cupping the butt of the pistol grip, gave a really steady picture through the scope. I was hoping for a cross hairs on target at 20 yards so that's how I was aiming.

1st shot right height but a couple of inches left. I adjusted the cross hairs on the scope having removed the protective cover. It had an arrow with "L" but does that move the crosshairs left or where the bolt impacts? Anyhow, try it and see.. I turned it 1/4 of a turn left (anticlockwise).
2nd shot, plus 2 others, to see how it grouped... 2" right and all bolts within a finger width of each other... click the adjustment back a bit.
The subsequent shots slowly walked left towards the 10mm black dot I was aiming at as I slowly adjusted the sight.
I cocked the bow for a final shot and though I'd see how it shot off hand (standing with no support).
The image was waving about all over the place compared to how it was when supported, but I relaxed a bit and brought the cross hairs smoothly onto the spot... now theoretically you should squeeze a trigger, well that's fine when you are supported and steady... conversely you don't want to snatch at it... BUT if the trigger is built and set up correctly it should pull in line with the shot and not kick the shot out of line.
(I'm no authority on this sort of thing and have little experience*... it's all just my opinion, so feel fee to disagree, comment etc).
So as I came onto target and popped off the shot... trying to stay relaxed, both eyes open.. it looked good as I saw it hit home through the scope, but it was hard to see exactly amongst the other bolts and holes in the target. A careful look though the scope revealed it had clipped the spot!
I was certainly happy with that, I'll have to try it at 30 and 40 yards sometime and maybe go round a field course, although it is to a great extent just an academic exercise.
Of course it was just one shot...

* I have spent a good deal of time however discussing these things with my brother who is a good shot with shot gun, air rifle and has even shot 303 at Bisley.

Crossbow Tinkering

I've grafted 20mm of extra length onto the end of the track, pretty much what I'd sawn off when working with the wooden prods. This gives extra draw weight and draw length which will give a faster flatter trajectory. Whilst doing this it became apparent why I was shooting all over the place, just about every screw and bolt was loose, presumably shaken loose by the recoil.
I got it all back together nice and secure, I also reserved the centre serving which had worn through, well the to be more accurate, the second layer had worn through, but the first layer was still sound.

Taking my brothers advice, I got myself set up in a seated position with the crossbow supported on a tightly rolled old duvet resting on my workmate at 10 yards range, working on the premise that I wanted to be aiming 3 dots low at 10 yards to give me the cross hairs on target at about 20 or so yards.
1st shot, steady as a rock 3" low 4" left. I wanted to adjust to the right and it became obvious that I had too many sources of error/adjustment. The scope rail is screwed into the wood block that covers the trigger mechanism/latch with 2 wood screws (plenty of play there) and that block is screwed into the stock with 2 off 6mm bolts which also have slop/adjustment. I slackened the bolts and tweaked it.
2nd shot, same height (good) 4" right. Adjust again...
3rd shot, same height (good) 1/2" left, that'll do for now.
Looking at the height, I obviously don't need to be aiming 3 dots low, as it's going low... try one dot low.
4th shot 1/2" high, 1/2" left. Well that's pretty good, but want to be aiming 3 dots low at 10 yards to give a good point on range. So I added a 2nd shim of thin tin plate (the first had been added before last weekends testing). The tin plate is 0.01" thick. Then I tried again aiming 3 dots low.
5th shot, about 1" high and 3" left ...
Well it's obvious I can shim out the height successfully, but the left right adjustment is too prone to being knocked out of kilter every time I mess with the shimming. I've ordered another scope rail, so I can pin this to the wooden block for consistent alignment and then tighten it down with the screws.
I've since pinned the existing rail and ordered some 0.015" steel shim and another rail (oh the joys of E-bay)

All in all very promising, but it shows that I probably need to use slightly larger screws in some positions and possibly be using Loctite to secure them. I also need to regularly check everything for tightness.
Interestingly my brother recounted how his good quality gas power air rifle had drifted out of adjustment after a period of storage ... 1/2" out at 20 yards (I'd be happy with that on the crossbow!)

Wych Elm Shot In

I took the Wych Elm to be tested today by JD the guy who had brought me the stave, it had a good few dozen through it and was lobbing heavyish regular arrows over the 200 yards with ease. It'd be interesting to see what it did with an out and out flight arrow. It was declared to be a nice roving bow and as such I'll get it finished up. It would probably work nicely as a field shooting bow too.

I'd also taken the crossbow out to try and get some sight marks at 20 and 30 yards.
I was v inconsistent, possibly due to a bit of a back strain, which I exacerbated when pulling out an obstinate bolt.
On the plus side I picked a bag of blackberries.

String Jig

Here are some pics of my jig for making continuous loop strings.
Made from some scrap bits of Dexion, the vertical bit is welded on (badly) but could be bolted.
An S shaped hook of wire (clothes hanger) is also needed to pull one side of the loop down and out of the way while the other side is being served.
Note:- The scraps of string tied to the dexion is just where I've tied the string as I start to wind it back and forth along the jig. It then gets cut off or undone and tied to the other end to complete the continuous loop.

I've just shown one end for clarity, it also shows how the two main lengths bolt together for coarse length adjustment, it will do any string from a warbow to a crossbow prod.
The hooks for each end are wire tensioning bolts with the loops opened up shaped and smoothed.(Other brands are also available)
I may add to this post with more description and illustrations as a resource for people wanting to make one.
I know someone who made a similar jig using that 2 slot shelving support and brackets. (see pic right)
Note fine selection of books :-)

Ha, just found this old sketch from 2011, which may be helpful for anyone who isn't familiar with continuous loop strings.
I don't bother with the masking tape now that I have my jig and my bent wire S hook to keep the two sides of the loop separate
Note:- A couple of extra strands can be laid onto the string where the loops will be whipped, if some extra thickness is required. I do this for very thin flight bow strings which are only 6 strand.