Thursday, 15 March 2018

Close But No Cigar

I'd had a good day helping my mate JT work on the Hazel longbow, the belly patch was worked down to blend in to the bow, but left a whisker plump, the horn nocks were roughed out enough to fit the string at a low brace and flex it, pulling it to 45# at about 22". It looked much better and the right limb which had chrysalled and gone weak now looked a hint stiff with the tiller restored to a reasonable shape. We quit there as we'd had a good session and didn't want to spoil the work by rushing.

By teatime I couldn't resist testing the crossbow and it worked nicely  201.1fps first shot, but then 200.5fps on the second and it then went on to loose about 2 fps of speed with each shot!
After 7 shots it was down to 188.8fps, I was just pushing it too hard, I'd taken a few turns out of the string to lower the brace height a whisker and take some strain off it to no avail.

Bang! The string cut deep into the nock on the left limb splitting down along the loser edge, this made the string slack and allowed the limbs to flex past their unbraced position splitting the belly lams away from the core.

If only I'd double served the loops or bound below the nock with linen thread soaked in superglue. Easy to be wise after the event, but even if I'd done those things, it may well have lost speed.
I've proved some aspects of the design, the bow mount, the Boo/Yew /Ipe combination, the 120# draw weight. The nock failure was at least different to the last one which virtually snapped off.
Am I down? Of course I'm not (well just a tad) I could buy a crossbow, but what would I learn from that. I'm hedging my bets, I've seen some nice maple slats on E-bay which I've ordered, these can be used with Boo/Ipe, or maybe I'll succumb to the lure of glassfibre laminations.
I'll probably have another go with the natural materials but with an extra inch on each limb, and better nock design. The belly lams will go right into the mounting/riser block this time so they won't simply split off if the bow flexes beyond it's rest position.

Wednesday, 14 March 2018

Frogs and Crossbow Progress

The frogs were just becoming active the other week when we had a week long big freeze, since then I've found 6 dead frogs and I was getting worried that the population had been badly effected. Last year it was they had spawned by March 5th.

Yesterday I was relieved to see one cluster of spawn and a couple of frogs. This morning, at least 4 pairs were writhing about and a good deal of spawn.
 All is well with my froggy friends!

Mean while I've pulled the crossbow prod back to about 14" at 120-130#. Its reaching the point where drawing it further will merely cause set in the bow rather than giving more weight. With this in mind I've taken 1/2" off the track and moved the bow mount back.
I've added horn nock overlays as reinforcement  and also added the string catchers (neither  polished up yet), these have been glued onto rubber sheet and that then glued onto the limbs, hopefully this will help absorb shock.
I'm currently making the string, (well typing this and drinking tea really). I may get to test it today, but I'm taking things easy having given my back a little tweak (groan). I was working on the floor mending our vacuum cleaner... the cable retract mechanism had managed to jam the cable such that you could only pull about 3/4 of it out. I was wrestling the damn thing on the floor to try and get it apart, I reached over for a screw driver and felt the back give a nasty twinge... not too bad if I keep moving, but not a great aid to a good night's kip.

Monday, 12 March 2018

Yet More Cross Prod Work

The Ipe from my mate Matt at Cambridge Longbows has come in very handy, as well as using it on flight arrows there was enough to make a pair of belly laminations for one of my crossbow prods. I have 2 prods on the go, the slowest one being used for experimentation. That one had a bamboo belly which I've taken off using my new draw knife and carefully taken down to the Yew core.

The Ipe was sawn on the bandsaw with some care to try and get nice clean parallel strips. It's not as simple as one might think, some careful set up and a suitable blade helps enormously. Contrary to what one might think, I've found a narrow blade seems to allow the wood to follow the guide best.
I'm using a 1/4" x 0.025" 4 tpi AS Hakansson Silko blade. (From Justbandsawblades)
That's a general purpose carbon steel blade, 4 teeth per inch Alternate Set. The alternate set cuts a slightly wider cut and helps avoid friction. Being a 1/4" blade it also allows you to follow quite tight curves, the down side is that it's not as rugged as a wider blade and you wouldn't rip down logs with it.

I still have the former from the last glue up of the prod, but the Ipe is too stiff to bend easily to shape without some heat bending first to get it about right. Once the Ipe was hot (using a hot air gun) I clamped it to the former to get the bend. As I heated the Ipe, it changed colour, going darker and tiny specs of oil came out of the wood. I have heard people suggesting that some oily woods be de-greased before glue up, but others suggest a fresh sanded surface is fine. I went for the fresh sanded surface. The Yew was lightly scored and all traces of the old glue removed. Glue up was with my usual Cascamite (Resintite) and plenty of clamps. (Picture shows starting to clamp it up starting near the centre to ensure it is nicely butted up against the centre riser block)

I've had the prod up on the tiller clamped up between two thick aluminium mounting plates, as it will be when mounted on the stock, to ensure it doesn't break at the shoot through cut out.
I've pulled it to about a 13" draw (measuring from the Aluminium mounting plate nearest the archer) and it's pulled about 125-130# I'm not sure if I dare pull it much further.
One consideration is that although the latch is at 14 1/4" one has to pull it beyond that to actually cock it and engage the latch, also because it is being pulled with two hands on the string that effectively shortens the string slightly pulling it even further.
I can always take 1/2" off the end of the stock to reduce the draw, I don't know yet, I'll proceed slowly.

Sunday, 4 March 2018

Freezing Cold

I've not posted over the last week, mainly 'cos it's been too cold to do much out in the garage other than a few minutes here and there finishing some flight arrows for the 90# @ ~27" Yew longbow.
I've been a bit more thorough about noting dimensions etc and I've got 4 nice arrows with varying weights and centre of balance etc.
Two are rebuilt from the 26.5" arrows which had the tips broken off, these now have footings added to make 'em 28", that's allowing a little safety margin in length to remove the risk if sticking the point into the belly of bow at 27" draw.
Still too cold and wet to test 'em but maybe next weekend.

I've picked up the boo/Yew/boo crossbow prod which was slower than the original boo/Yew and I've taken the boo off the belly using my restored draw knife, it's a joy to use but too long to fit in my drawer. It's a bit lethal to leave it on the bench as the cutting edge is so long, so I'm making a leather wallet for it. I like working with leather and once it's all cut out and punched I can sit indoors in the warm to stitch it.
The game plan is to glue an Ipe belly onto the crossbow prod, it will all be guess work and may need 2 strips of Ipe side by side for each limb, as the stuff I have isn't that wide. If that fails I may have to resort to laminating a prod using glass or carbon fibre, not really my thing, but still an interesting project. It prob seems bonkers to some people that I'd be doing all that when I can but a reasonable crossbow for about £150. It's just the fun of it, to see what I can produce. Keeps me out of mischief too, mind I'm not sure how much mischief I could manage these days!
With the bit of snow we had I did manage to make a snow cat :-)

Oh, I've also noticed that the feedback tick boxes at the foot of each post seem to be working again, which is nice as I can see that I'm not boring everyone rigid... Google works in mysterious ways!

Been out in the garden, the ice covering pond is starting to thaw but I noticed 4 dead Rudd floating under the ice, these are descendants of fish that my brothers and I caught as kids. There should still be a reasonably healthy population. I expect Emily Cat will be trying to get 'em out when the ice finally clears.

Saturday, 24 February 2018


I'm a bit gutted, I'd spent a lot of time patching the Molle' and as I strung it the patch lifted. So, I re-did it with a longer patch blended in and sculpted to match the ridges, it looked lovely.
I strung it and it was fine, but when I got it to 3/4 draw BANG and it exploded. Examining the break showed that it was a miracle it had lasted so long. When I made the bow I'd had to graft fresh Yew onto the belly side of the levers as they had long streaks of black manky material in cracks running along the grain. It can be seen from the pictures that this rot extended down into the body of the bow and into the feature "eye" knots.
I was dubious about the chances of a clean repair, and maybe it was an accident waiting to happen. I don't know if it's owner will want it glued back together as a "wall hanger".

Meanwhile may mate JT had got the hazel ELB back to 50# at 24" . Our aim for the session was to get it braced, evenly tillered and back to about 21", that all went too smoothly and we pressed on.
I should have urged him to use the finer rasp and to slow down, we'd taken video but pressed on without reviewing it... all a bit rushed.
A little over enthusiast rasping and pulling it to 55# caused a couple of chrysals on the belly.
This threw the tiller off and made it look very weak in the upper limb. He was gutted ,but we eased off the outer limbs, put a string on it and shot about 15 arrows. It was surprisingly fast, and now the initial disappointment has subsided we've decided to patch the belly and take the bow to completion with horn nocks etc so that we've gone through the whole process.
While he was working on the bow I was refurbishing the drawknife which I'd bought, the main effort being turning a couple of steel ferules on my little lathe. At least that went well!

Monday, 19 February 2018

Molle and Arrow Repairs

I'd been putting off working on the Molle' as I wan't sure what I'd find once I started chiselling out the splinter and I had various other odds and ends on the go.
Once I'd had a tidy up of the garage and spliced a laburnum footing onto a flight arrow that lost it's point on Sunday, I plucked up courage to start work.
The sap wood was V shallow where it was forming a splinter and as I dug down the heart wood was a bit rotten for a few mm depth. I've cleaned it out and I'll glue in a nice sliver of sapwood cut to a V section. In the pic you can see the heart wood is also showing along the ridge running down the centre.
I'll fiddle about this afternoon and see if I can get a nice bit of sapwood to fit, it can take a few attempts to get a nice match and a good fit. I may need to cut way a bit more to make the patch longer as a long thin patch gives a better glue line than a short fat one.

I've been testing the Yew flight bow to try and establish the maximum safe draw before it starts taking set. It had been drawn to about 25" on Sunday and had all night to recover. I laid it against a straight edge and measured between that and the belly (at the centre of the bow), the gap was 4mm. Then I put it on the tiller, pulled it to 27", took the string off and re measured... the gap had opened up to 12mm, but after about half an hour it had relaxed back to about 7mm. It will be interesting to see how it is tomorrow.
Update:- Yup, it's back to 4mm  :-)
I reckon that 27" is pretty much the maximum draw without it starting to take permanent set. It's a short bow and at 27" draw it looks like it's working hard and has real full compass look to it.

Oh, and here's a pic of the drawknife I bought off E-bay, with my one for comparison.
On top of the drawknife is the sanding block I made for arrow shafts. I ran my router along a couple of scraps of 2x1 , very handy.

Friday, 16 February 2018

Catching up after a Busy week

Forgive the positioning of the pics in this post... the editing software won't let them be moved around sensibly (Grrr)

A couple came over to collect the lighter Hazel primitive last week, we had a fine time and had a go with all my crossbows as they'd not shot one before. The Chinese repeater was greatly enjoyed and I even had a shot with my 275# repro medieval "light sporting crossbow" which is pretty spectacular in a confined space like my garage.
The larger primitive (see previous post for pics) was shipped off and the recipient said:-
"Wow, it looks absolutely gorgeous!!!! Really striking & beautiful bow"... "Draws up lovely. Really smooth. It feels much smoother than my Ash bow despite the fact that it's higher poundage and shorter length. Nice one Del! Thank you".

I've been working off and on with the Yew flight bow for this season and flight arrows too of course. The constant striving for an arrow of small diameter for minimum drag yet stiff enough to withstand the acceleration and flexing. I fancied trying Ipe as an arrow wood and remembered that my mate Matt (of Cambridge Longbows) had been recently using some. He very kindly sent some off-cuts in the post for me to play with.
The first Ipe shaft I made was slightly smaller diameter than my reference shaft  at about the same stiffness ("reference shaft" sounds a tad grand, it's really just one that had snapped off it's point), the bad news was that it was about 25% heavier! My next idea is top secret, so don't tell anyone, I cut a thin slat of Ipe and glued it up between two bits of straight grained pine, so it looks like a jam sandwich. This gives it more stiffness especially sideways without too much weight increase. I made a shooting board so I could plane the corners off to get it roughly round, I then turned it on my lathe. I also grooved a couple of bits or board to use with sandpaper as sanding blocks for smoothing shafts.

I had a couple of visitors with a yew stave that they wanted turning into a bow, then the next thing I get is an E-mail from a chap for whom I'd made arguably the best looking character I've ever made. It's a Mollegabet style from very marginal Yew with lovely  sharp ridges down the back and knots like eyes near the levers.It had started to lift a splinter on the back (shown by red arrow in the pic). He arranged to bring the bow over to me mid week and it was good to see both him and the bow again.
I haven't started work on that repair yet as I'm in the middle of some other stuff.

Meanwhile I've been working with and guiding my mate JT while he makes his first ever bow (a Hazel ELB), it's coming along and is ready to brace. It's a very wonky stave, but that's ok as it teaches how to cope with the problems. It's very different to working a clean flat even laminated stave.
It was a pleasure to have JT working the garage and to see the progress, his first use of the spokeshave was rather tentative, but after a few hours, he was taking off long shavings with confidence to get the left limb flexing to match the right, and the bow was beginning to flex evenly, ready to be braced.

Just to round off the week I saw a nice old draw knife on Ebay, the handles were split, but the blade looked like it had never (or hardly ever) been sharpened. I stuck in a bid for £16 max and won it! I'll clean it up and sharpen it later.
Throw in some work tuning up the lathe, a visit from my brother and an Indian take away... great week!
Just noticed three frogs in a clinch at the bottom of the pond... spring is on the way!