Needle Bow II

I had a skinny offcut of Yew which I patched up to make it thick enough in the middle and then glued on a scrap of Ash as a backing, it's only 55" long and no wider than my thumb at the widest, the upper limb is even narrower.
I just did it for the fun of it and even had to overlay a patch on the side of the tip to correct the string line due to some waggle at the end of the limb. It's about 33# at 27" and shoots very nicely being so narrow. I did a video of the whole process from glued up to being shot:-
https://www.youtube.com/watch?v=juag-r3zlD8&t=77s

Ash Backed Yew

 I've made an Ash Backed Yew for myself I was aiming for 80# @ 32" but I may be a whisker under as I was using some scruffy offcuts of Yew glued up as billets. Once the billets were Z spliced together and the Ash back glued on (with about 1" of reflex at the tips) I could see it was a tad thin near the centre so I glued on a strip of similar Yew about 4mm thick, which bought it up to just about enough thickness. It made it a bit tricky to tiller as the added on section was a bit stiff at the very centre but still left a slightly thin area where it faded out. I made a video of the whole tillering process as someone had been asking about it.
Del's Tedious Tillering Video
I haven't actually got round to making a string for it yet so it's not been shot... mind I can only shoot it at 10 yards at the moment.

Whilst sorting my Yew and sawing out the various billets I created a skinny Yew off cut, (top left pic) once again, this had a rather thin area, so I added a patch (top right pic) and then glued the back on so that it was over the patch, leaving a nice clean belly.The back was a similar Ash off-cut making a rather thin 55" bow, this has been a good quick tillering exercise, with most of the cleaning up and wood removal being done on the belt sander! I'll edit a video of that later on, it'll probably just about make 35#@27" and will be called Needle Bow II.

The Corona virus lockdown hasn't been too bad for us as we're luck enough to have a fair amount of room, a reasonable sized garden and stuff to keep us busy... I must admit I was sufficiently bored at one point to resort to cleaning the cooker hood, I also cleaned the car which is something I usually do about twice a year. I really feel for those stuck in small flats with young kids and no garden. We live in strange times.

I couldn't resist adding the pic of the Alconet flowers, it's rather invasive, but the bees love it. Small flowers but very cheerful, there is a lot of blue in the garden at the mo', vast swathes of Forget-me-not and the Rosemary has it's dusky blue flowers too

Crossbow Prod Details

One of my online friends asked me about the poundage obtainable from some 20mm wide glass laminated crossbow prod of say 36" long
Of course it depends on plenty of factors... is it a one piece prod or individual limbs which have several advantages but some disadvantages.
Individual limbs can be adjusted to angle back or forward with tapered shims and will allow a centre shot, the downside however is that you sacrifice some working limb length in the mounting clamps.

Anyway I said I'd provide some pics and dimensions which should allow him to do some back of an envelope calculations to get some sort of ball part figure.
One thing to note is the nock which has a substantial horn overlay and is bound with carbon fibre soaked in epoxy, this is needed to stop the string cutting into the limb tip and splitting down it.
Dimensions:-
Overall nock to nock 37.5"
width x thickness at root of limb 44 x 8.3mm
    "              "        "       mid limb 37.5 x 6.8mm
    "              "        "       tip            25.6 x 5.6mm
Brace height 3" power stroke 12" draw weight ~90#

20mm wide glass seems a bit narrow, sow maybe two pieces could be used side by side to give 40mm , obviously that's easier to say than to do as glue ups are notoriously slippery, but maybe two bits could be joined edge to edge with a few tiny spots of epoxy to hold them together?

All this sharing of info seems to have increased during the Covid19 lockdown as people are communicating more. I did a You tube video for one bloke giving hime more details of my belt drive conversion on my mini mill.
Any how keep busy one and all and try to stay safe and sane!

Crossbow Bolts and Warbow Arrows

There's been a lot of interweb activity due to Coronavirus lockdown, much of it has been an irritating waste of space, but there have been some sensible discussions.

One chap was questioning if warbow arrows were sorted in spine in any way... some people chipped in asking why "random arrows" would be all put in a barrel together. Of course that sort of comment is weighted to support his own position... the arrows were not "random" they were made to some sort of specification (albeit, maybe not a written one) in that they would have been suitable for warbows, say 3/8 - 1/2" shafts, big long fletchings (3 per arrow), heavy head, between 28 and 32" long. We know from documentary evidence that the shafts and heads were not necessarily assembled where they were made, so sheaves of shafts and barrels of heads would be sent up to the Tower of London. maybe one bloke cut all of his shafts the same length, maybe they were trimmed to length when they were made into arrows.
The point is we shouldn't jump to conclusions. What we do know is that measuring the spine of an arrow shaft by hanging weights on it and doing arithmetic is a modern idea. Now that doesn't mean that a native making arrows for his bow didn't flex 'em to select those he liked best or flew best, but, spine wasn't actually "measured"...
Ah, but does it even matter?... The bloke who asked the question had no real experience, and was just quoting what he'd read (sigh). So, as well as stating my experience I thought I'd better back it up with an actual experiment.
Does the spine of a Warbow arrow matter? Well we know they fly pretty well out of heavy warbows, but what happens if you shoot one out of a 70#@32" bow? It should theoretically be over stiff in terms of static spine*. Then if we shoot a 5/16" 30"arrow of 40-45 spine from the same bow what happens? Does the sky fall in?
Well the heavy arrow hits the boss square on at 10 yards having straightened out already due to the heavy head and big fletchings. The light arrow is still flexing as it hits at 10 yards, but they both fly in a perfectly usable manner. (see pic)

To keep me busy I've been turning up some 3/8" points for my heavy 275# repro "Light Sporting Crossbow" It uses up some odd Ash shafts I have lying around and some of the feathers I picked up the other year. I'll post some pics and video when I test them in the crossbow.
I've finished one bolt and tested it from the crossbow. It flew nicely at 10 yards, I also checked the spin by lobbing it up in the air underarm and watch it spin as it fell back down. The 2 fletchings are slightly offset to enhance their natural curve to induce spin. You can see on the pic of the fletching jig I have stuck a bit of white card under the front edge of the clip that holds the fletch, that just lifts it a tad.


* For those who don't understand the difference between static spine and dynamic spine.
Static spine is simply how the shaft flexes when a weigh is hung from it's centre... but when it is shot from a bow there are other factors like the weight of the head... if the head is very light, there is very little to stop the arrow accelerating, so there is little force bending it. With a heavy head, there is lots of inertia, so rather than accelerate forwards the arrow will flex.
Taking this to the limit, and a 50 spine arrow with a 15 grain head can be shot from a warbow. Conversely an infinitely heavy head (which is simulated when you over draw and jam the point of the arrow into the belly of the bow) will cause the same 50 spine shaft to explode! The length of shaft also effect dynamic spine...if you pick up a 3 foot length of scaffold pole and give it a shake it feels rigid. If you pick up a 20 foot length holding it at the centre and jerk you hand up and down you can feel it flexing.