Tuesday, 26 June 2012

Another try with Hornbeam

I wanted to try a different wood from the usual Yew and Hazel, my previous attempt with Hornbeam broke where I'd tried to straightenout a big sideways bend.
This time I'm letting the stave dictate the bow, it has a huge natural reflex which a bit of deflex at one end. It's fairly short and wobbly too, so should be a challenge. My bandsaw blade snapped (it was getting a bit blunt) so I've gone back to basics and am using my axe. Oddly the bandsaw doesn't like the Hornbeam, it's heavy and dense and gives off a sweetish slightly cloying scent a bit like cow parsley or Sweet Chestnut as the saw blade struggles to cut through it. The axe seems to love it though! I had visions on sore fingers, tennis elbow and blisters, but I've been chopping away at the back outdoors enjoying a bit of sunshine with no ill effects. In the picture on the right my finger shows about where the tip of the bow will be the very end which kinks to the right being sawn off. The first pic shows that I need to weed the patio, hmnm maybe that would be a good name for a gardening based computer game?... don't spose it'd catch on, more a pull 'em up rather than a shoot 'em up. Final pic shows my progress so far. I'll make it fairly wide an flat to allow for the huge bend needed to even get to brace height, maybe I can end up with a high initial draw weight which then increases slow and smooth? Who knows, we'll see, and that's part of the attraction. I'm probably looking for about 40# which is a nice manageable weight.

Monday, 25 June 2012

Final, Final Tiller adjustment

Having been angsting for days about the draw weight of the bow and it's slightly stiff lower limb, I gently ran the rasp down the sides of the last third of the lower limb.
Removing wood from the sides has less effect on the poundage and ideally should remove more mass than taking it off the belly (for the same change in draw weight).
I cleaned it up with the scraper and put it back on my newly adjusted tiller. It looked a bit better and was drawing 25.5 pounds at 24", great! Previously it was about 27.5 which I felt was just a little too much.
It seemed to shoot a trifle smoother and sweeter, but that's probably just my fond imagining and the fact that having shot a hundred plus arrows over the last few days I'm getting my eye in!

These two pics illustrate what I was saying in the last post.
The tiller looks lovely now (it's at 26" ~ 30#) 24" is now about 26# so that's about 2 pounds an inch so we can extrapolate to give 34# at 28" which will be ok to grow into.

Symmetry or Not?

Warning! This could get tedious!
Most bows aren't symetrical. A longbow is fairly symetrical but the centre of the grip is usually a little below the true centre of the bow and the arrow pass about an inch above the true centre. This compromise gives a smoothly working bow. This assymmetry also gives rise to the practice of making the lower limb slightly stiffer than the upper.
On the tiller, any assymetry can look confusing* and one trick to overcome this is to reverse the bow and look at it round the other way. E.G. I always have the top limb to the right, so I flipped the bow I'm doing now to see it it with the top limb to the left.
Whaaa? It was maddly out, the bottom limb tip was much higher than the upper.
(The normal way had bottom tip about an inch higher at full draw, whereas it was about 4" higher round the other way!)
I shifted it on the tiller a bit to make it look right and wondered how it could be so different round the other way.
The only answer could be the tiller isn't set up true, then I remembered...
Ages ago I had rather hurriedly made a new support block (that the bow rests on) which holds the bow about and inch or two away from the wall when I was tillering a very crooked stave. I make the block curved at it upper surface so the bow can rock back and forth as if lightly supported in your hand. Maybe I'd made it lopsided?!
A quick check with a plumb line and spirit level revealed that I was off centre by about an 1/8" to the left but the curve was skewed too making the left side higher, all in all it was probably nearly 1/2 an inch out to the left. (But between having the bow one way and t'other the difference would become 1")
In the grand scheme of things 1/2" isn't a big difference, but conversely, why have it wrong when a minute with a rasp and making a new pencil mark can leave it spot on?
Sorry if all that was a bit laboured, but I see pictures posted on Primitive Archer by people wanting advice on the tiller of their bow as it progresess. The tillers are sometimes all on the skew and the bow clamped in the centre so it's not free to move.
Any measurement is only as good as the reference point.
I realise we can't all have a standards laboratory as a workshop, and indeed mine certainly isn't. I've even used a tiller tied to a tree, but I tried to get it vertical. It does illustrate that my policly of always have the top limb to the right was at least putting some order into the uncertainty.

*When a (long)bow is on the tiller resting as it will in the hand and drawn from where it will actually be pulled it sits rather tilted early in the draw. As it is drawn further, this tilt slowly corrects. It's tempting to clamp a bow on the tiller dead square and pull the string from the centre. I do this on occasion, but bear in mind it isn't representative of a real draw.
I try to minimise the effect in my video clips and pictures to some extent by supporting the bow, just below the arrow plate, which would be a reasonable simulation of shooiting with the weight of the bow is taken on the ball of the thumb, rather than the palm or heel of the hand.
After all the tillering in the world, the real full draw photo can still be revealing.

Sunday, 24 June 2012

Grip, Arrow Plate, and Bowscale.

Got the grip and arrow plate done. The Mother of pearl looks great against the dark pinkish red leather, but it's a pig trying to catch it in a pic'.
I've shot over 100 arrows through it now and it's performing well.

I bought a new spring balance yesterday from poundland, it's only a dirt cheap plasticky thing sold as a luggage scale. It goes up to 50# and actually works very smoothly, it's ideal for lower poundage bows as it gives a better resolution. I can spot calibrate it for accuracy against my other scale. With most measuring instruments it's best to be using them somewhere near the middle of their range, so this is much better for a 25# bow than using my 200# scales.

Working Mother of Pearl is slightly tricky, it will saw, grind and file if you use a light touch, a decent saw blade and letting the weight of the saw do the cutting and cuts through quite easily, it's a bit brittle and will crack if gripped too hard. I put a scrap of rubber sheet around it and nip it up gently in the vice.
Final pic is the modified scale from Poundland (I've seen 'em in the 99p shop too if you want to save 1p!)
I've added a double hook of stout steel strip like an archers fingers so I can hook it onto a bow string while the bow is on the tiller.
It gives a lovely smooth reading with half pound resolution. I've spot checked it at 30# against my big scale and it actually seems to have less backlash and stickiness in the movement. On the big scale I have to allow 2 pounds for the weight of the scale and tapping it can make the reading shift by a pound or so.
I've very briefly taken the bow back to 28", which shows it has plenty of room to be grown into, I was also thinking that this might just ease off the draw weight a pound or so. I'm continuing to shoot it in using something nearer my full draw, probably about 26-27" rather than deliberately short target style draw. Hopefull by next week it will be thoroughly settle in and any adjustments I need to make won't then result in sudden tiller changes or sharp losses of draw weight.

Friday, 22 June 2012

Nocks, String and Shooting in.

I've done the nocks in black Waterbuffalo horn, normally it comes out solid shiny black, this piece has a grayish white streak in the centre which gives it a distinguished and decorative look. Waterbuffalo horn has a small line in the centre a bit like the pith up the middle of a branch, often it's flattened into a seam rather than a tube, normally it barely shows, or looks like a fine crack. I've managed to cut the two nocks from the same piece of horn which gives matching nocks. I had been thinking of inlaying a dot of silver, but that wouldn't look right with the nice white/grey streak.
I've given it a wipe over with Danish oil so that I can see the colour and surface finish better. It is very much like the other bow from the same quarter stave (that was the one with the Devil's thumb print). It has a patch of that darker wood and some attractive streaks of reddish colour.
I shall get a decent string on it and give it some exercise.On the tiller at 26" it's looking a really good shape now and having sat at full draw for a minute or so it's reading 30# so I'm pretty close. Pulling it briefly from braced to 24" read about 27# which will do for now.
I'll get the string made and take some pics later.
Woo, it spits out those arrows! I made a 6 strand Angel Majesty string, padded out at the centre serving with 6 strands of Dacron so that it doesn't slice your fingers off. The brace height is fairly low, but probably in proportion to the length of the bow 5 3/4 "
I'm shooting it in using my lightest arrows and just drawing to my lips with my left arm slightly flexed. It shoots rather well considering the arrows are prob' a tad stiff for it. I was just snap shooting, and it was grouping ok, feels strange shooting from a short draw but it feels predictable and a bit like my Hazel flat bow, which I s'pose would be a similar weight at 24"-26" draw.
It's looking like it's about 27# or 28# at 24" so it may be a bit over, it will be good to let her try it and see how it suits. I don't know what her technique is like, if she's using a 'target' style draw using mostly the right arm, it may require a slightly more 'warbow' type draw coming up from a low start point using both arms, back and chest in a more dynamic draw, no time to hang around on target before loosing either. Obviously I won't let her use it if it's too much for her, but I think field shooting is made for a more dynamic style... The longer I spend 'aiming' the worse I get.
Stare at the target, bring the bow hand up and out punching it towards the target and as the right hand hits your anchor 'and' loose.
The 'and' is the length of pause, none of this standing at full draw for 5 seconds.
All just my opinion and style of course, doubtless a target archer would wipe the floor with me over known distances on a regulation target. I think field shooting with a self wood bow is a totally different discipline.
If you were being attacked by Zombies would you rather have a target archer or a field archer alongside you? Yeah, and if it was Vampires, you'd definitely want the field archer with the wooden arrows.

Thursday, 21 June 2012

Kid's Yew ELB Full Draw

I've been told the vital figures for the bow, I'm looking for 25# at 24". Which is pretty much the same as the 30# at 26" I'd been aiming for!
The problem with this sort of thing is:- I pull the bow back to 25# and it's 22". I then winch it back so I can step back and have a look but, as I stand and watch I can see the scale needle creeping downward as the bow relaxes slightly until it's 25# at 24"
This is all quite normal. However relaxing a few pounds on a 60# bow is hardly noticeable, but a few pounds on a 25 pounder starts to look significant. Anyhow, I've stopped tillering for now and will think about nocks, grip and arrow plate. .
The recipient is a 12yr old girl who is 'quite girlie' so I'll go for a Mother of Pearl arrow plate and I have some nice bright red leather for the grip, I might even have some slightly pinkish stuff.
I've just re-strung it and taken a pic' it looks like it's back to 30# @ 24" ! You can see the shape is rather good now.The left tip looks a tad stiff, but there's a hint of natural reflex near that tip. I may have a closer look and rasp a whisker off the belly over that last 1/4 of the limb. Fitting the nocks will allow some re-tillering of the tips anyway as they will get significantly slimmed
Currently it's got a rough sanded finish, so by the time I've given it a good going over and shot it in it will probably be about the right weight, I'd rather have it over than under at the moment, as simply leaving it strung for half an hour would doubtless settle it down to about the right weight. No good making it 25 @ 24" if it's going to relax 5 pounds over a mornings shoot.
The Ash kids bows I made for the club ages ago (the first post on my blog I think) are pretty much like sticks of rhubarb now, mainly due to the silly specification, too short and too low a draw weight.

Monday, 18 June 2012

Yew Kids Longbow

It's great to get back to working on a bow.
The problem with this bow is I don't really know the height of the intended recipient, the draw length or draw weight! I'm aiming for 30# at 26" as a reasonable start point. I don't expect she draws 26" so the weight should be manageable. Hopefully I  can get it shootable and let her have a try out before finishing it.
Here are unbraced, braced and 30# at 18" pictures to show the progress. Whoops I got into the shot a bit, but it shows the bow still.
The stave has a bit of natural deflex, which I'm not going to do anything about as it will help to keep the draw weight low, and make it easier to string.
It's back to 30# at 20" now, with a bit more flex in the right limb. I expect I'll have it back another couple of inches by tonight.

I'm not being too fussy about following rings on the back, in fact I just took it down to a reasonable thickness with the spokeshave. I've since tidied it up a bit with the rasp, coarse side then the fine file side. With such a light bow there won't be too much room at the tips for excess sapwood, so I'll just have to reduce it as needed. I'll try and keep it as even as pos and follow a ring if it happens to work out that way.

Sunday, 17 June 2012

Getting Back to the Bows

Whew, I finished refurbishing the central heating, which of course coincided with some cold weather and the wettest drought on record. I've had to reorganise parts of the garage/workshop too as there is now a big flue coming through the wall right above the work bench.
It looks a bit like something from 'Wallace and Grommit' I half expect to hear a clanking noise and have a mug of tea appear down the flue.
I've still been on the bow making forums and thinking about bows, just haven't touched one for a fortnight.
Anyhow I've been tidying up, looking at my staves and planning what to take on next.
I've a kids Yew longbow roughed out and a real knotty character Yew longbow slightly roughed out.
The Yew billets from the Cascade mountains will need some careful poring over before I decide to use the sap wood and risk any insect damage, or to back with bamboo.
I want to have another go with the Hornbeam too, I've a couple of skinny wobbly staves to play with.
I shall finish cleaning out the garage this afternoon and pick up a stave to work on.
The club was a tempting prospect this morning, but the weather is already getting duller and my shooting fingers are still a bit sore. I was tightening a screw at an awkward angle and felt a shooting pain up the palm as I strained the tendons of my middle finger. Fingers heal pretty quick as they get so much use, but my elbows are a bit sore too. Drilling 110mm holes through the wall is a bit tough, I've still got the bruise on my pec' to show from the drill kicking back!
It's amazing how powerful yet delicate the human hand can be, if you are in doubt just pick up a pair of bathroom scales in both hands and see how hard you can squeeze. I haven't tried it lately but I used to be able to squeeze over my body weight. The mechanics is pretty impressive too, the muscles being up in your forearm. If you hold your arm up in front of you (hand rotated so you look at the back of it) and waggle your fingers you can see all the muscles working and the tendons waggling between hand and the point of your elbow, where they are attached. Which is why the tennis elbow is so easily aggravated.