Sunday 27 February 2011

A Good Day

I took the new Yew bow (with new string and arrow plate fitted) to the monthly 3D shoot shoot at the club.
I'm feeling my age now as shooting a 60 pound bow round 30 targets was hard but enjoyable. (I usually shoot my 40 pound Hazel primitive) It's persuaded me to re-tiller my 75lb bow down to about 60 as I'm sure I couldn't manage shooting it all day anymore.
The bow shot nicely, on the first target I put 3 arrows over the top as I wasn't used to the flatter trajectory. I soon got my eye in and shot to my usual average standard.
It turned chilly in the afternoon and I had to really think about breathing in and expanding my chest on the draw to fight my tiredness, I finished with some good shots, including a first arrow kill on a 3 foot tall rubber Cobra from about 25 yards!
I got home to a quick bite, a hot shower, a well earned cat nap, and I've just had a good old fashioned Sunday roast...Bliss!

I'd tested the bow on the tiller last night 62 lb @ 28" and 72 lb @ 31" most satisfactory.
Some pics tomorrow.
62 pounds will allow it to settle down a tad, and allow for any extra sanding and polishing over the week as I apply the final coats of Danish oil, Beeswax polish and a leather grip.

Friday 25 February 2011

Nearly There

I've done the nocks, they have been buffed up, but no final finish applied yet. Some imperfections still show up whiteish but will disappear when the final finish is applied. Some blemishes and imperfections are to be expected in natural materials.
In trying to keep the nock size and weight down to a minimum I've cut through and revealed the wood at a couple of points, this isn't a problem more of a feature (hmmm I make it sound like a Microsoft product!). There is plenty of precedent for the nock going down into the wood as the Mary Rose bows show a shallow nock groove on one side where the horn side nock was fitted (the horn was eaten away underwater). It can also be seen on modern bows.
I think it looks good, what you don't want is to cut down to the wood at the back where the nock is protecting the wood from the string pressure, the horn should also still form a complete circle around the tip for maximum strength.
Hmmm having said that, this style of nock is a pain and a simple horn tip overlay would work just as well even on heavy bows. Sometime I'll have to try the simpler side nocks as used on the Mary Rose bows, there are only one or two actual horn nocks surviving. Alan Blackham has a good website with some excellent stuff on side nocks which he has investigated and tried out to great effect, google his name or 'backstreet bowyer' if you want to know more.

I've actually shot the bow at 31" draw a couple of times now, I prefer this to winching it back to 31" as I can actually feel it and it isn't held long at that draw. It certainly banged out the arrow and it hasn't taken any more set. If the weather is ok at the weekend I'll get a proper string on it and start shooting it in.
There are file marks visible in the wood in the second pic (the bottom nock), and there's still plenty of work to do, but effectively it's a working bow now.

Monday 21 February 2011

Nock Fitting

I've posted pics of doing horn nocks before, but rather than repeat the same old pics, I'll try and add some detail to show more of how it's done. The blog is in danger of becoming the same for each bow, "Not another Yew longbow, groan". I must admit, I'm feeling the need for a break and might take on a more interesting bow just for myself next, there's plenty I want to try. Maybe even a really simple Hazel stick bow as I have a skinny piece with shiny bark which I couldn't resist cutting wau back last August, it would be fun to see what I can do with it without recourse to my tillering rig or any sophisticated tools, just an axe and a file.
Anyhow enough daydreamings, here are some pics.


First pic shows drilling the horn with a wood boring bit which has been ground to shape with a little grinding wheel. The pillar drill (or 'drill press') is a great tool, they are pretty cheap and an asset to any workshop, I call it my poor man's lathe.


The next shot shows where I've put a bit of masking tape on the back of the bow and marked 1" down from the nock, this will give me a reference point to measure from when the horn nock is on so I can get the nock in the right place. I've put the offcut from the roughed out stave on top so you can see how much it's been worked down.


You can also see me shaping the tip with a bit of sandpaper in a block of oak, the oak is first drilled using the same shaped drill. The tip of the limb is rasped roughly to shape first.

The final shot shows the horn nock next to the tip before fitting, you can see how far into the horn the tip will go, the thick pencil line was made with the nock in place. I haven't left too much fancy end protruding as I want to keep the overall bow length down, and this particular nock probably has the wood going up further into it than some. Shaping the nock requires a bit of patience as its very fiddly to hold, even when it's put onto a bit of old broom handle filed to a point. I contrived to rasp the fingers of my left hand a couple of times... ouch. I've glued it on (with a rapid epoxy) I'll continue shaping it once that's had a couple of hours to cure. The open end of the nock is cut at a slight angle, this is just my personal preference, I think it looks better, also it allows the circular hole in the nock to fit better against the relatively flat back of the bow, if you look in the pic you will see the left edge of the bow doesn't blend so smoothly into the curved section. Dunno if that makes sense, maybe you need to have it in your hand to see what I mean. If you really want to know, add a comment and I'll annotate a pic...

Friday 18 February 2011

Full Draw

Here we are, it's about 64 pounds @ 28", that gives me a few pounds to play with. I may take 1/2" off the lower (left) limb as the bow is for a shortish guy, it's 71.5" at the moment, but as it's going to be tested back to 31" I don't want to make it much shorter.
The tiller looks pretty even. I've shot a few arrows from it with the tillering string and it feels good.
I shall smooth it off and spend some time thinking and looking before I do anything drastic, then it's horn nocks and shoot it in. Or maybe I'll make a decent string, shoot it in and then do the nocks. Any way, that's enough for today.
The right tip looks slightly stiff, but it's the one with a tad of reflex (Note: in the first pics a few posts back that was the left limb. Because the bow was trying to twist and I had to have it that way round so the wall held it in position and stopped it twisting off the block. I generally have the top limb to the right...dunno why)

Thursday 17 February 2011

Full Brace Height

The 60lb Yew bow is coming along, I've been taking some off the belly with a spokeshave. I stretched a line from tip to tip to true up the straightness now it's been flexed a bit.
I've now got it back to about full brace height (6" judged with my fist and upturned thumb, a recognised 'rule of thumb' the 'fistimelle').

60lb now gets it back to about 22" and the shape is a bit better. My bit of heat bending has eased off that bit of deflex.
One tip of the bow is trying to twist slightly and bend off to one side, it's a matter of easing off the stiffer edge for the last 6" of limb and keeping an eye on it, the sap/heartwood boudary is slightly angled at that end.
A bit of twist isn't an issue as it will settle to it's final state as the bow is tillered and drawn a few hundred times (it gets flexed about 20 times on the tiller to it's full 60 pounds at each testing), it's just a matter of avoiding any sideways bend which could suddenly get worse.
As the draw weight is reduced the thickness will decrease, this will make it easier for the bow to bend back rather than sideways, so it should all be ok. Tillering is about trying to stop things going wrong before they happen, and coaxing the stave into becoming a bow.
Comparing with the previous post you can see the tips of the bow are coming back about another brick.

I've had it up on the tiller again and the slight twist is looking much better , the right limb is doing a bit more too and it's now back to 23" at 60 pounds.

As spring and spring cleaning is in the air I've decided to patch up the 'up and over' garage door which has some how got some holes in it (whoops!). The paint is also coming off too where arrows have struck and flexed the metal as well as making holes. I've filled the tiny holes and I'll give it a lick of paint tomorrow.
I've got some big foam blocks (rescued from the council tip) which I shoot into now, so hopefully the door will be safe.

Monday 14 February 2011

Yew Longbow

I've just started to tiller the next Yew longbow, I'm aiming for 60 pounds at 28" but with the bow being tested back to at least 31".
I've got it braced to about 3" and I've pulled it back to 60 pounds, it's tough as old boots still and it's hell's own job to get a string on it. I've had to use a stringer, which I rarely have to bother with. You can see it's flexing a fair bit in the centre, (especially on the right limb) so I need to ease off the outer limbs, but it's fairly even.
The left limb looks like it is a bit stiffer, but then it started without that bit of deflex at the end.

I'm taking out that deflex at the end of the right limb as I just don't like the look of it, and it makes the tiller look uneven.
I'm doing it with my hot air gun rather than my usual steaming, I've got it jigged up with the hot air on it at 230 degrees and lightly clamped to apply some tension. I'll leave it under the heat for an hour and then give it a few days to settle back to it's normal temperature and humidity.
250 degrees is fairly gentle.

Sunday 13 February 2011

Eucalyptus

I cut the Eucalyptus limb down to a useable length. There may just about be a bow lurking between the knots and bends. I painted the cut ends to stop it splitting and started to debark it with the draw knife. The bark is very thick and wet with a shiny outer surface and I soon found that once down to the wood the bark was lifting off fairly evenly. I got an old decorating knife under it and was levering and stripping it off in long leathery slabs.
The bark came of in great strips spiralling down the limb as I stripped it off which indicates the grain is probably spiral too. Twisted grain is no good for making a bow, but I shall persevere with it as it will be fun to make some sort of bow from a tree I've planted myself. I might try pounding the bark too to see if it splits into useable fibres to make a string which would be satisfyingly 'primitive'.

Saturday 12 February 2011

Pruning Eucalyptus

Beautiful day today so I've been lopping some of our Eucalyptus, it's huge, we planted it when we moved to this house about 16 years ago so it's pretty fast growing stuff.
I was up an extension ladder to reach this bit, I don't know if I'll be able to get a bow out of it, but it would be fun to make a bow from a tree which we planted.
I finished off the grip of the 'Needle' bow and added a cow horn arrow plate, I've not used cow horn before and I used a criss cross stitch on the grip for a change which seemed to work nicely. I've given it 3 coats of Danish oil too.

Monday 7 February 2011

A Word About Moisture Content.

I don't often use my moisture meter, generally just relying on feel and giving the wood a year to season.
However:- I just tested the offcut from the Yew stave I've been working on and one edge which had been exposed to the air for a long time gave a reading of 10% which is fine, but another face, recently worked read almost 15% which is rather 'wet' still. I think this shows the value of working a stave down rather than leaving it for a year and then taking off vast quanties of wood and expecting the centre to be seasoned.
Maybe I should have de-barked it even sooner (I think I did it last month), perhaps I'll give it the warm radiator treatment once it's a bit closer to approximate dimensions (I wouldn't do this on a fresh stave or one which wasn't worked down for fear of splitting due to drying too quickly).
I've spent a fair bit of time on it today and worked it down as a squareish cross section with my drawknife.
It's begining to flex, so I'll probably round off the corners on the belly and think about getting on the tiller next week.

Next Yew Longbow

Another bow already?!
Because I've been slowly de-barking and roughing out last years Yew staves over the last few months, I have a couple which are coming on quite nicely. The pics show marking a straight line down the stave with a string line, the dilema is do you straighten the stave with steam bending or just mark a straight line down a crooked stave? Well, you will rarely find a dead straight stave and a bit of compromise in fitting a straight line is no problem especially with Yew.
One of the later pics shows the bends in the other plane, which don't matter so much, a bit of recurve is a good thing, as one expects the bow to take a few inches of set during tillering.
I don't much like the little bit of deflex near my hand, I may consider steaming that back to match the other limb, or just making that the lower limb.
With a self bow I don't want to steam out all the character, if you want a perfectly uniform straight bow, then you can buy or make a laminated one. I'll see how it comes along during the early stages of tillering before I decide.
The shot of the end grain shows how I've reduced the sapwood thickness to just 3 growth rings(that's an offcut from the stave, where I've reduced it to about 6') . I've followed the growth rings along the whole length of the bow, this is a painstaking process which needs a bit of practice, but these rings are fairly thick and as you remove the last vestiges of the ring the wood is white and slightly crumbly a bit like cooked chicken breast meat and it scrapes or rasps off fairly easilly, the trick is getting good illumination at the right angle to show the change in colour, also do a little and often (a touch of the hare and tortoise!)
If I was after maximum performance I'd probably steam in a couple of inches of reflex, aiming for a straight bow when finished, it doesn't make that much difference though. My 75lb Yew bow has a fair bit of set in it and a bit of reflex in one limb and deflex in the other, and shoots beautifully.

Sunday 6 February 2011

Needle bow pic

The bow is slightly stiff tipped and the tiller isn't really spot on, but if I adjust it I'll loose draw weight which I can't afford to do.
It shoots a respectable 132.6fps (feet per second) through the chrono which is about right (rule of thumb is draw weight in pounds plus 100 as a fps speed).
The slight kink (looks like a slight hinge) in the upper limb is where there's a knot and a bend in the stave, so it's not as bad as it looks.
I shot it at the club yesterday (100 arrows I'd guess) drawing a full 28", it did pretty well.
I prefer a fatter grip, more mass and draw weight, but I still hit some nice shots and it certainly does the job. I'll do a grip sometime and maybe stick a sliver of horn on as an arrow plate (it's too skinny to inlay one).
I've done Waterbuffalo horn overlays on the tips to provide some material to file the nocks into.
It should make a nice first bow for the intended recipient.
Of course as I was putting the bow away in the garage I couldn't resist a little go with the cabinet scraper on the tip half of the limbs and also a tad near the grip, it's probably made little difference but I couldn't resist!

Friday 4 February 2011

The Needle Bow

I've nick named the thin Ash bow the 'needle bow' as it's so thin, the draw weight is only about 28 pounds at 26" but it still feels pretty lively and will pull to 28" safely.
I made the string pretty thin with just 6 strands of Dacron (I usually use 8 for bows of about 40 pounds) but it seems I've made it a whisker long and I've had to twist it up a lot to shorten it. I think some of the work I did on the nocks effectively shortened the bow a tad.
Hopefully I won't need to re-make the string, I went for a thin one to keep the string weight down and the arrow speed up. Maybe a fastflite string would help, but I didn't buy any when I last got some supplies in as they only had the latest ludicrously expensive stuff in stock and I didn't want to pay an extra 20% vat so that the PM can spend it employing another 'Communications Director' rather than keeping the price of petrol down.

The bow seems to shoot nicely. Being so thin there is little paradox (that's to say the arrow doesn't need to flex much to get past the side of the bow). A leather grip is needed to fatten it up a bit.
I'll shoot it in a bit before I do any more work and I'll post some pics over the weekend.
The speed seems ok for such a light bow, I think the stiffish tips and thin deep cross section help, it will be interesting to shoot it through the chrono.