Monday 27 February 2012

Miniature

The second nock is now done and I've finished the first. You can see the difference...
Where it meets the wood is cleaner and is a better blend in, fewer tool marks showing. 400 grit wet & dry paper and a buffing wheel gives the final finish.

By the way about a week after my last bow exploded on the tiller I took some more moisture measurements on the Yew in may garage and it was all back to a more typical 12%. I'm not going to draw conclusions here, but I shall be wary of tillering bows during long spells of cold dry weather.

Saturday 25 February 2012

Miniature Horn Nock

I found that the best way to do it was exactly the same as I'd make a full sized one. I had to re-grind the tip of one of my tools to get the finer taper and I even made a small version of the fitting tool to sand down the end for a good fit.
It's not 100% finished yet, but you can see it's coming on rather nicely.

I realised, I'm still about an inch short of the target draw length, because the rule on the tiller is adjusted to measure from the back of the last bow I did which was over an inch thick.

Friday 24 February 2012

Miniature on the Tiller

It looks a bit funny a tiny bow on the full sized tiller, but it illustrates that the process of making the bow is exactly the same as making a full sized one. A lot less work, but some of which is maddening! It's an absolute pig to string as it is just one strand of Angel Majesty. Originally I used a strand of Dacron, but it was stretching!!
Draw weight is 10# at just short of 14".
You have to look closely to see the string, maybe I should have zoomed in a bit.
I shall quit there and put some horn nocks on it, I did shoot one of my lightest arrows from it just for fun, it stuck it into the target just fine. It would be amusing to turn up to Sunday's shoot with it and a tiny quiver full of arrows.
Finding something suitable for a 1/2 scale arrow will be tricky.

P.S I could have cropped the pics, but I took them exactly the same as I always do to allow ease of comparison.

Thursday 23 February 2012

Wood Wasps and Stuff

I don't know exactly what creature has caused the damege, but I think if I can find any billets with no visible damage they should be ok.
The grubs munch about in the sapwood but eventually exit as a mature wasp (or whatever) by eating out to the surface.
Thus if there are no holes at all visible on the edges or surface then there were no grubs in there, (unless they are still in there and not come out).
It's a risk I'm willing to take, so I shall examine all the wood with great care and then build a bow from a pair of clean billets.

It's our end of month 3D shoot on Sunday so I'm practicing in the garage, just a few shots now and then, sometimes just one shot if I hit the spot first time. No point carrying on until I miss! I don't want to practice missing, always finish on a high.

I'll do some more to the miniature, doing tiny horn nocks should be interesting, but stringing and drawing the bow will be a bit nerve wracking.
I s'pose I should say what I'm aiming for?
It's about 35" long, so that's about 1/2 scale in linear terms but in terms of volume and mass it's about 1/8th so I'd expect the draw weigh to be down by a factor of 8 (remember stiffness of a beam is proportional to the cube of the thickness).
Let's say if it was full size it would be 48 pounds at 28". Then to scale I s'pose it should be about 6 pounds at 14" .
I don't expect my physics or maths is actually right, but it's good to have some sort of idea what I'm aiming for.

Monday 20 February 2012

Staves, Billets, Borers & Stuff!

Bit down after the exploding bow and I've been reviewing my remaining Yew staves. Not the best I've seen, one good one, one with a mass of small knots and a concave back which will be hell's own job reducing down to a sensible thickness of sapwood.
The remaining two are a bit short with assorted blind knots... hmm maybe I'll take two good pieces from them and splice 'em together.
So, I think I'll have a break from those staves and play with an offcut of the High altitude Yew from the US and make a miniature longbow (about half size) as a present for the guy who sent it.
Now miniatures are funny things, people see 'em in museums and gasp at the work involved, yet oddly there is much less work! It's finer work, but there is less of it!
As an example imagine forging a 4 foot long steel crossbow prod that is about 4"x 1/2" at the centre... impossible without a huge forge and plenty of muscle power time and skill, whereas the 1/5th scale version can be cold forged on your workbench vice with a ball pein hammer!
Anyhow, back to the plot, I start roughing out the miniature and my heart sinks when I find borers (wasps beetles or some such that they get in the USA) have got into the sap wood at one point.
Damn, but forewarned is forearmed, I shall have to examine the other staves with great care.
Fortunately the borer hadn't gone right through the sapwood and I can leave a thin layer which is enough for the miniature.
I've cheered up a bit now, by working on the miniature (about 1/2 size) and shooting a few arrows into my target in the garage and a few from under the wooden pergola in the garden. It's a bit of a trick shot, threading it though the ivy and the garage door.
Can you spot the target, a small white spot?

Sunday 19 February 2012

Onwards and Upwards

There were a couple of suggestions that the wood in the exploding bow was possibly too dry.
Too dry in our climate? Surely not. I got my moisture meter and could hardly believe it, the moisture content barely registered on the heartwood where it had broken, reading 7-8%, yet the sapwood measured about 12% which is typical of any wood in my garage.
Strange, I reached for my 'Traditional Bowyer's Bible Vol 1' where they discus moisture content, below 5% is considered fatal, so maybe the heartwood was fine. After all the big 90# bow was from the same timber.
It's daft to leap to conclusions, far better to just concentrate on the facts. The interesting thing being that the heartwood can be at 7% while the sapwood is at 12% despite a year seasoning.
I confirmed this on some of the other Yew on the shelves. Maybe this is all tied up with the different properties and feel of the heart vs sap wood? (Note:- A week later and all the wood is reading 12% ! The weather has changed from the couple of cold dry weeks we'd had. I'm not drawing conclusions here, just reporting what I measured)
Oddly I checked a bit of the Oregon Yew and the heart wood on that wasn't so dry.
Anyhow, time to look at the Oregon billets so I cleaned up one edge of one of the shorter thinner billets and marked it out for sawing.
Looking at the sapwood on a billet is deceptive as it is wider than the rest, once the edges are cleaned up and you allow for the width of a saw cut, it can be very tight trying to squeeze a pair of limbs from one billet. What I did was to always aim for one good billet and if I could get a second or third, that was a bonus. It's also a mistake to saw one and then assume the saw line is straight and mark off that for another. You are drawing lines on an undulating curved and probably twisted surface, then running it through a saw without a smooth flat reference edge or face... it isn't going to be straight.
You can see in the first pic how I've cleaned up the left edge (which had been split from the log, the right edge had been sawn) and marked my limb. (about 28mm at the wide end and 18mm at the narrow, I allowed more for a warbow on one of the bigger billets)
Of course a commercial saw mill would square everything up, ruin the sapwood and waste a ton of material. You can see the twist on the right piece.

I've just noticed the 'explain more' box ticked on the previous post.
Ha! If only I could explain it all, then maybe it wouldn't have blown on me. I expect a forensic laboratory could possibly work out where the failure originated...
The bottom line is it blew, I don't think I made any glaring mistakes, the usual mistake is rushing, and I certainly didn't do that.
As one of the guys on Primitive Archer said. 'I guess that piece of Yew just didn't want to be a bow'
I think that's what I enjoy about making bows, you can't know what's going on inside the wood without slicing it open and having a look, you can't always analyse it, some wood will just twist for no obvious reason. It's not an even homogeneous material that lends itself to computer simulation and machining by numerically controlled robots. It's about feel, the anxiety in the pit of your stomach as you turn the handle of the winch. The elation of the first arrow and the sheer joy of that exquisite parabola as the arrow soars through a clear blue sky.
Whoops, getting a bit poetic there, pull yourself together old chap... have a nice cup of tea.

Friday 17 February 2012

That's about it...Oh!

Friday morning I gave it a good going over with the scraper and cleaned up the back a bit more. The (fairly fine) rasp & scraper combination works well.
I wanted some off the right limb so I drew a pencil line along the belly where I wanted to take it off. I rasped off the pencil line and got it back on the tiller.
I repeated the procedure a couple of times, it's now back to almost 26" at 55#. The scraper cleans off the rasp marks without effecting the weight too much.
Near the tips I use a coarse file as there is less wood to remove.
I shot one of my heaviest arrows into my foam back stop just to try it the penetration looked pretty good.
The set in the bow has come up to about the thickness of my thumb now.
It's virtually there now except for some fine tuning to check the string alignment and clean it all up.
It's odd, I've got it back to about 26" and it doesn't seem to want to come back the last few inches despite a lot of scraping and rasping and tweaking, (Usually the last couple of inches of draw take very little work to get there).
I then got another 1/2" and BANG.

The whole thing disintegrated, interestingly, it hasn't simply gone at one of the features or slightly suspect places, the whole thing seems to have gone at once, splitting along the neutral plane about halfway through the bow.
More pics and autopsy later. You have to be philosophical when making bows, I got away with some nasty knots on the last one, so I don't begrudge some kindling for my Sister's wood burning stove.
I think the break probably started at the knot which protrudes through the back despite there being plenty of sapwood there .
I've sawn a section through the area of the knot (at an oblique angle to show it better). It looks pretty sound and you can see the extra sapwood I had allowed around the knot. (The pencil line shows the profile of the rest of the limb)

Thursday 16 February 2012

Getting Close

I've been teasing away at the 55# Yew Longbow. It's at a reasonable brace height and pulling 55# at 22" at the moment.
The feature knot protruding through the back has been carfully worked down so that it's not too stiff or heavy, it still protrudes.
The bow is feeling light and lithe now, I can get the string off it now without the stringer, but cant' quite get it without it yet.
There's plenty of early tension in the bow, it's taken a just a whisker of set such that if I lie the belly of the bow against a straight edge I can just about get my little finger under the handle.
The last bit of tillering will probably pull a little more set into the bow, one or two fingers worth is pretty good.
There are some nice swoops and bends in the bow which make it interesting, they can be rather off putting in the tillering process and it's sometims easy to confuse the natural curves with weak points or stiff points.
I expect to get it back to 28" and be shooting it in over the weekend, but these last few inches need to be done carefully to spread the load nice and evenly along the whole bow.
On some of the forums I read people say they tillered a bow in an hour. Yes it can be done, (I've made a Hazel bow in hour flat) but I like to take it slowly and savour it. It can be nerve wracking winching on those last few inches.

Update:- A few minutes with a rasp and it's back to 55# at 24" the upper limb is a tad stiff but it's creeping back slowly. You can see that in comparison to the previous post it's flexing much harder now. As it's a fairly short bow the end result should be an impressive curve.

Monday 13 February 2012

On the Tiller at Low Brace

The pictures pretty much speak for themselves. I've taken it back to 50# at about 15". The upper limb is to the right and you can see some of the steam bending has alredy pulled out, but it's pretty straight overall. These pics help me view it from a distance as in the garage I can only get about 6' away from it conveniently, whereas the camera is mounted on the opposite wall, as far away as is possible.
I'm pleased with it. The lump in the left limb where the knots protrude through the back is flexing smoothly (it had been a stiff area).
The narrow area on the right limb had show as a weak spot, but is now moving smoothly with the rest of that limb.
The string had been trying to pop off the nocks as the tips are narrow, I've superglued a sliver of Yew onto each tip to make the nocks more secure. The bow will have horn nocks eventually. The last pic shows the temporary overlay and the grooves for the stringer, which I need at this stage as the draw weight is still quite high.

Saturday 11 February 2012

Nearly Ready for the Tiller

I've reduced the sap wood some more where it was rather thick, following a ring where possible but not being too rigid about it. The belly has been rounded, so it's pretty close to the final shape.
There are some really nice features showing on the bow now.
A big knot on the side has all but disappeared leaving a nice sort of figure of 8 swirl in the grain. On the lower limb there is a knot protruding though the sapwood with a couple of small pins too, they all look nice and solid, the sap wood has been left thick there for extra security for the back of the bow, it's a fine balance, as too much extra will cause a stiff spot, which is dead weight and not contributing to the power.
Once the bow is finished and polished these features will really stand out.
The sharp edge between side and back will of course be rounded and blended in a bit, it's a bit slab sided where the sides meet the back at the moment, but that's what gives a longbow some of it's D cross section.
I've just about pulled it to get the tips back to brace height on a long string, which is at about 50 pounds draw weight.
The next step is to get a proper string on it at a reasonable brace height.
I think it will turn out to be a really good looking bow with just enough character to be interesting without spoiling the performance.

Update: I've had it on the tiller at a low brace, plenty of draw weight there. The upper limb is little weaker than the lower, but it just needed about 3mm off the belly of the lower limb over it's last 1/3 to get them looking better and the overall curve looking reasonable. Next step is to get it to full brace and cast a really critical eye over it.
The important bit is that the skinny top limb is looking ok despite being a whisker deeper than it is wide at one point, with no sign of try to bend sideways.
there is still plenty of draw weight such that the tip will get reduced slightly and become a perfectly normal cross section by the time it's fully tillered.
Damn cold out there today as there's not the bright sunshine we enjoyed yesterday.

Thursday 9 February 2012

The Generosity of Others

It seems that we are an affable bunch, I try to help people out here and there, and that's one of the reasons for this blog.
I recently got a contact on my website from a guy in the USA who was looking to clear out his 'raw bow woods' collection. This Yew was cut back in the early 90's. The Yew was found at around an elevation of 2000 to 2500 foot in the Cascade mountain range.
He was hoping for some advice and direction....what is it worth, to whom, etc.
Well, I offered some advice and expressed my personal interest.
Unfortunately he hadn't realised I was in the UK, and overseas shipping is a cost issue especially for his full length staves.
However with great generosity he sent me 4 of his billets as a gift (about 45" long to be spliced into staves) so I could at last try out high altitude Yew and see how it compares to English Yew.
So a huge thank you to Joe.
You can see how it compares with the English Yew I'm currently working with, (English Yew on top). The sap wood layer hasn't been reduced at all on the piece from the Cascades and has a really clear heart/sap boundary.
I sanded down a small area to show the grain, it felt harder and denser than the English wood. If you click on the pic to enlarge it you'll get a better look, but the grain just under the sapwood is so fine you can't make it out.
There are endless discussions about the qualities of high altitude grown Yew vs English Yew, and my stance is that it may well be better (I'll soon find out!), but that's not to say that English Yew doesn't make a fine bow. It's also not necessarily the reason why it was imported for bowstaves.
It was imported because the supply was there and we could levy a tax of so many staves per ton of goods imported.
The fact that it was high altitude Yew may only be due to the fact that fertile valley land had been turned over to farming! All this is just my opinion of course, but had the Dutch been cultivating Yew for bow staves maybe we'd be be clamouring for sea level grown Yew?
I can't wait to start work on the billets, they are very dark and tight grained and have lovely thin sapwood which will not need working down. Yew darkens with age and I've worked English Yew as darl as this, but none with such consistently tight grain.

The shipping cost was pretty steep and HM Customs made me pay import VAT due to a mix up over the value. Hopefully I can claim it back.
The other day, I made the schoolboy error of sawing to the wrong line with my bandsaw, fortunately I spotted it just about in time. A mistake like that is a timely warning, and with the Cascade Yew, I shall be ultra careful and spend plenty of time cleaning it up and measuring before stepping anywhere near the bandsaw.

Meanwhile, the steam bend on the current longbow has had plenty of time to settle down and looks pretty good (the steamed limb is the top one). The bow now has about 1" of reflex overall, which will doubtless settle out during tillering.
BTW. The snow isn't really blue! The camera screwed up the colour balance, but it shows of the yew nicely.
I've popped the bow up on the tiller with a long string and wound on 40 pounds of pull, it barely shifted which is great. It means I have a fair bit of wood to play with. It's looking good, I'd been worried about going too light and too narrow, but I'm a bit more confident now.
It's a bit cold to do too much in my garage, but that will stop me rushing at it.
Slow and steady wins the day (other platitudes are also available)

Sunday 5 February 2012

A Spot of Steam Bending + Bow in the Snow

I've worked the stave down during the day, and the skinny top limb looks more in proportion now that more wood has been removed from everywhere else.
It has some nice undulations, however a bit of deflex bend near the tip of the skinny top limb isn't in balance with the lower limb and will rob the bow of some speed and draw weight.
It also makes it more difficult to tiller as it will always look like the slight bend is a weak point.
A Yew longbow will generally take an inch or two of set as its being tillered, so starting with an inch of deflex doesn't help.

I was a tad reluctant to bend the tip as there is little room for error as it's so narrow.
But what the heck, I want it to look right and perform well and the worst that can happen is it needs a second dose of bending (which isn't a prob).
I've done a very localised bend by confining the steam using an old 5L plastic container.
The plastic container has a hole cut in either end so the bow actually passes through it, some old plastic foam loosley plugs up the gaps around the bow to stop the steam getting out too quickly.
The far end of the bow has a brick tied to it, so that as the steam softens the wood it gently pulls down under the weight of the brick. You could actually see it slowly creeping down.
It only took about 5minutes steaming as the tip is quite a small cross section (about 20mm x 20mm).
In the pic you can see the wallpaper steamer I use to generate the steam, the flexible pipe is covered with a bit of old duvet to help keep the heat in and a bit of plastic is there to run the drips off onto the floor. The whole set up is at an angle so the drips run off and the Yew isn't sitting in a puddle of hot water.
As we had some snow, I used it as a nice white backdrop to photograph my 90# Longbow. It needs a light background else the bow tends to bleach out, unless I mess around with the manual settings on the camera. It's also quite tricky to get a good pic of something so long with it all in focus, without resorting to tripods and all that malarkey. Maybe it needs a Robin sitting on the arrow?

Saturday 4 February 2012

Teasing out the Bow

It's damn cold in the garage, but I can't stand being stuck indoors all day.
I've been tinkering with the stave, that blind knot has been rasped away, leaving the stave fairly thin. I then made a mistake and went a bit wild with the draw knife, it bit deep and started to split deep into the stave about 1/3 of the way along one limb. I was drawing toward the tip of the bow, but obviously the grain wanted to go into the limb. I stopped and used the spokeshave to cut in the opposite direction until I'd taken the split right out.
The limb is very slim now and I don't have any spare length in the stave.
That's why it's best to work a stave about 6" too long, if you meet a nasty feature or make a mistake you can saw 6" off and re-position the bow.
It's probably be ok, but will have to be for one of my shorter, lighter commissions.
On the up side, a slim deep limb section is inherently lighter than a wide shallow one so it may be nice and fast.
If the limb is deeper than it is wide there is a risk it can try to bend sideways, so it's safest to keep the depth no greater than the width.
It's down to me to tease a bow out from between the knots and swirls of this stave, and that's what makes it interesting. By the time I've finished I'll know every inch of the stave like the back of my hand.
Worst case is it's too light and short for what's required, in which case I'm sure I'll find it a home as a ladies / junior or club bow.
Only time will tell and just for the record, I'm aiming for 55# at 28" which may be a tall order.
On the other hand, what looks dangerously skinny now having just built a 90# bow, may well be perfectly ok.
Anyhow time to step away from the bow and have a cuppa, it's a wise man who knows when to take a breather.
It doesn't look quite so worrying after a cup of tea, and I can probably loose 3" off the thin tip and keep it about 69-70" long as the guy it's for is about 5'9" and that will still look ok.
Maybe some pics tomorrow or Monday.