Tuesday 31 August 2010

Tillering Video 1

I've had a fair bit of E-mail on the subject of tillering so I thought I'd try to show in video what it's about.
The bow I'm working on is the Ash Meare heath style flatbow shown in earlier posts.
Here's a link to the video:-
http://s411.photobucket.com/albums/pp195/Del_the_Cat/websitevideos/?action=view&current=flatbowtiller_0001.mp4

I did try to stick the video directly in here, but it seemed to take ages and snag up.
Maybe I'll try again for part 2, which I'll do as the bow progresses.
Meanwhile, I'm sure clicking the link won't be too tiresome for you all!
Let's try embedding the video. Ooooh, that seemed to work ok.

Friday 27 August 2010

bank Holiday Weekend

I've finished the drawers at last so I can have a good tidy up of the garage and get back to working on bows. There's a big Primitive Crafts event at the club (Celtic Harmony Camp) over the long weekend I'll go along one of the days and help with the have-a-go Archery, I always find it uplifting how well people generally take to it and enjoy it.
I think it's ingrained in some primitive part of our psyche.
It amuses that on some archery websites the modern target archers go into minute details of aiming and 'form' yet the one thing you never need to instruct anyone is how to aim... they just seem to get it. Mind I s'pose it's not rocket science, you don't need to tell anyone how to point a stick, although, having said that some creatures (notably cats) don't understand the concept of pointing at something...just as well the don't shoot bows I s'pose.
Enough whimsey!

Monday 23 August 2010

Distracted

I was hoping to do some tillering this weekend, but I built the camera mount, then I found my bandsaw was slightly in the shot.

I needed a good clear out, but as I started I found some plywood and thought I could make some drawers for my archery stuff which is all over the place at the mo'.
Wouldn't it be nice to have a draw for 5/16" fittings, one for 11/32", one for string making materials etc?
I've been meaning to do it for ages, I measured up and decided to go for 7 drawers (I was trying to think of some sort of bad 'Snow White and the seven drawers' joke [groan] but couldn't come up with anything).

Anyhow the drawers are progressing, they're a bit rough and ready, but it's used up some scrap, hasn't cost a penny and will result in an increased coefficient of garage tidiness. It's not taking too long as I could do most of the cutting on my table saw or bandsaw.

Here's some pics, now I was going to use my little 'snap' camera to take a pic of my decent camera on the mount, but of course the batteries were flat! So the little 'un is on the mount instead.
It doesn't really show, but the mount is adjustable in tilt and pan for alignment. Very rough and ready again, but it does the job and I couldn't get a tripod into that position. The knob which screws up into the camera is just an old bolt with some big plywood washers glued onto it and then turned on my "poor man's lathe" (The pillar drill), I think it adds a sadly needed touch of class.


Friday 20 August 2010

Getting Obsessive?

One of the problems with my tiller rig in the garage is that I can hardly get far enough away from it to see the bow or take good pics.
I had the idea of taking pics from exactly the same place as I tiller the bow. So...I've made an adjustable bracket on the opposite wall which will hold the camera in a fixed position, it's so close to the wall that I need to use a mirror to see the picture on the display!
It should mean that I can take good sequences, video, or even animate the stages of tillering.
Now this may be of interest to some and may even be useful, or maybe it's just a sign that I'm fed up with decorating the bedroom and wanted to tinker in the garage.
I don't s'pose a tillering animation will gross as much as Toy Story III, but it'll be fun to do.
Pics later at the weekend.

Monday 16 August 2010

Tillering


I've been E-mailing back and forth with a guy who's made his first bow, he had some problems tillering, but managed to make a working bow and has done a second already.

To try and help with tillering I shall post some pics as I proceed with the Ash bow.
I've been experimenting to try and superimose pics, havn't succeeded yet, but this cut & paste pic shows how the stave is starting to move from a taut string (but not actually braced) to 40 pounds pull, which is somewhere near the target weight.
It's important to get the bow moving evenly as early as possible, but of course this is easy to say.
At such a small deflection it's easy to think the centre of the bow isn't moving. By the time a fault is obvious it may be too late. You are trying to see the signs of a problem before they really become too obvious.
You can see the bow is bending slightly near the handle and along both limbs. The left limb has a slightly sharper bend at one point about half way along, and it looks slightly stiff near the handle.
The handle looks to be tilting very slightly down on the left side.

Nothing to worry about, but the trick is to stop it getting any worse, I shall mark a big W on that possible weak spot.
Now these effects are very slight, and I've actually re-written the previous paragraph drawing slightly different conclusions! This illustrates that it's a subtle process done a little at a time, it's a matter of stopping it going wrong, rather than actually doing it right.
Hmmm I don't know if that makes sense, but you are slowly removing wood, but taking care not to remove it from any suspicious areas. Each time I put it on the tiller and pull it back to 40 pounds I might not see any difference, or just a subtle change or maybe an extra half inch draw.
As the bow thins and comes slowly back each little bit of wood removed makes more difference. E.G 0.2mm removed from a 10mm thick bow makes more difference than 0.2mm removed from a 12mm thick bow.
If I keep pulling back to 40 pounds, and avoiding anything bad happening, eventually it will get to 40 lb at 28" draw and the job is done.
So it's a game of patience, which will amuse some of my familly as patience isn't my strong suit!

Saturday 14 August 2010

Ash Bow work in progress


Just a couple of pics to show I'm not skiving off!
It's just begining to flex a bit on the tiller, but nowhere near back to bracing height. It's just flexing back a few inches, but is coming back fairly evenly.
I'm working to reduce the belly whilst keeping it flat.
You can see from the pic on the right I can't flatten it much more without it breaking into the curve of the back.
It doesn't look much different from the picture a few posts back, but it's been trimmed to length (58") and had tillering nocks cut in.

Friday 13 August 2010

Devil's Advocate

Mr Hutchison you stand accused of willfully breaking a bow, you complain after the event that it was too short, yet you deliberately sawed 15" off the stave! [gasps from the gallery]
How do you plea?


[Gulp] Not guilty your honour.
I crave the court's indulgence to permit me to explain.

The stave was extremely thin at one end with insufficient wood to work into a tip.
A longer bow would also be of lower draw weight (a long beam being more flexible than a short one).
If the bow was longer, the handle would be nearer the thin end and we were strugging to make the handle thicker than the limbs to allow it to be narrowed to a grippable width.

May I remind you, there is no 'we'? It is you who is on trial.

Just so your honour, may I present two pictures in my defence?
The latter shows how the stave was barely more than a thin lath of wood. It also shows that additional recurve would have been introduced which would have exacerbated our problems.


















After reviewing the evidence I conclude that although there is 11mm of wood on that tip which is possibly enough for a tip, your other arguments cannot be clearly dissproved and you were probably just a little precipitous is removing so much length.
Case dismissed due to lack of clear evidence.
However, I expect you to take more care in future and I have no wish to see you before the bench again.
Case dismissed!
Thank you your honour.

Wednesday 11 August 2010

A half day Bowmaking.


I spent an enjoyable afternoon giving Paul (who is a violin maker) an introduction into bowmaking.
It was at a breakneck pace as we went from stave spotting in the woods, splitting a log, through roughing out a skinny piece of seasoned Hazel and on to the technique of tillering.
The aim was to cover all the processes involved and if possible end up with a working bow of some sort (a rather optomistic aim).
The piece of Hazel we used was rather thin and had a huge natural recurve (see pic left), it was a bit I'd been saving as 'it might have a bow in it'.

The big advantage was, being skinny, was we could rough it out quite quickly with an axe and move onto drawknife, plane, spokeshave and rasps...but of course there was that 'might' .

As a violin maker Paul's skills were well honed, but those required for bowmaking were a tad more agricultural, I don't think there is much call for axe work when making a violin!

We had a fine time and he'd bought along a couple of his beautiful violins, which my daughter tried and was awestruck by them! I'm not musical, but I loved the way they resonated as you spoke anywhere near them!
We pretty much finished the bow, having used a multitude of tools and techniques, rules of thumb and good old guesswork.
Unfortunately it was getting late and in a rush to get back to a useable draw length there was that dreaded 'TICK' as it fractured at 24" draw, 30 pounds weight.
I'd optomistically set a target of 26" @ 30 pounds which was pushing it for a stave only 58" long with a lot of natural recurve. I felt that setting a target was a vital part of showing the tillering.
I was bending down watching the draw weight and length, but not looking at the curve of the bow as I pulled it back to see how far we'd got. There's a good lesson there somewhere!
Paul had done a good deal of the work at every stage and had seen the highs and lows of tillering, marking the weak spots and where to remove the wood, and watching it slowly come back from recurved to braced and starting to draw. If we'd had more time we'd have ended up with a working bow.

I was a bit down having fractured it, but retrospectively it was still a very good afternoon and Paul took the bow back with him as it provides a good reference point.
Other than the haste, the failure was due to the bow being rather short for it's draw especially considering the couple of inches of recurve on the stave.
It took us a fair amount of work to even get it back to braced, and interestingly it still had some recurve on it after it fractured, which is probably a testament to the virtues of Hazel.

It was interesting to do a one to one session, we crammed a lot into about six hours! It made me realise what would be involved in actually doing a 'course'... lots of hard work!
I'd think two people max would be the limit, and a big workshop or a sunny day would be a must!
All in all a most enjoyable day and a few bottles of red wine were a very welcomed gift from Paul for my efforts.

Monday 9 August 2010

Work in progress Ash bows

The Meare Heath style bow is ready to put up on the tiller. The guy I'm making it for has a young lad and I found this little Ash bow I'd done ages ago which I'm reworking for him.
It's actually the bow I'm pictured steam bending and roughing out with an axe on my website in the 'Other stuff' section.
I think they'll make a nice pair of bows, the little un draws 14# at 20" and 20 # @ 24", it's always tricky to know how far to take out the draw length on kid's bows.

I had experimented with the little bow and backed it with glass fibres from glass rope (used to seal my gas boiler flue) stuck down with PVA wood glue (Ok you can tell I must've been bored to try that, but it worked quite well in bringing up the poundage. Not recomended however!) I've removed the glass and narrowed the tips.
Here's a pic of it at full draw when it still had the glass backing, you can see I was giving it some serious testing, the right limb was begining to chrysal (compression crack) just right of the handle where a knot goes through the limb, there is a tad too much bend there, I don't know if you can see it. Viewing the curve of a bow is a matter of 'getting your eye in' . There are various tricks to help like taking a picture and drawing curves on the computer, but these generally just confirm what your eye has told you. (I sometimes think that in the modern world we've forgotten how to look).
Of course it's now drawing considerably shorter than that and the limbs have been narrowed from mid point out to the tips, to make them work better.

PS. I finally coiled that old bandsaw blade! Go on, cut a long strip of paper, tape it into a loop and see if you can coil it into 3 concentric loops without any twists! (I bet my big Sis will try it if she reads this!)

Friday 6 August 2010

Hazel Harvesting.

It's not the ideal time of year, one should really wait til the leaves have fallen, but it's not a big deal. Let's just have the pics!
Spot the stave in the left pic!
It's that nice straight limb growing up just right of centre.
The top section isn't as straight as it appears from this angle but I got a lovely 6' piece and a slightly wobbly 5' piece.
You can see that after cutting it, I've tidied the cut up to a nice angle so the rain will run off, it will die back cleanly, and may regrow from just below that point.

I've included a shot of thinner Hazel wands growing up, the colour variation is startling, the dark redish bark is like that on the Hazel bow on my Website, the more silvery bark is more common, yet they are both growing from the same trunk. This sort of thing is what makes tree identification so tricky (especially in winter when you are more likely to be cutting timber.)

I cut one other piece, rather skinny but with nice bark, there was little growing from the top of it, so I wasn't harming the tree. It might make a quick survival bow, by just chopping away the belly and putting a string on it, really primitive.
It's the vertical bit growing up from the big angle limb bottom right.

My memory was playing tricks on me in the last post, the big piece hasn't got smooth bark, it's the little runty bit which has the gunmetal smooth bark, maybe that's just Bowyer's optimism, limbs never look quite so good second time round!

Wednesday 4 August 2010

Bits & Pieces

I've got the Ash bow worked down to floor tillered stage, that's to say it's flexing a tad when I lean on it. I can tell it's going to be a handsome bow, but not if it will need de-crowning yet.
I'm going to try to hold off on putting it onto the tiller until next Wednesday when a chap is coming round for a look at bowmaking for the afternoon.
Meanwhile I've worked a bit on that Hawthorn bow and it doesn't look quite so bad now, that will be handy for some tillering demonstration too.

My axe and bandsaw blades arrived, the axe needed sharpening (I checked on the web for axe sharpening videos, just to confirm I knew what I was doing... which I did) after a little time with a file and then an oilstone I could slice paper with it, which is sharp enough! It feels really nice, the head is 0.6 kg compared to the 1kg of my old one, nicely balanced and much easier on the wrist and forearm.
I put on one of the bandsaw blades which is a bit of a fiddle at the bandsaw needs readjustment to a new blade. The 'Alternate Set' blade cuts a slightly wide cut than the standard, but is less likely to bind when ripping down a log.
A bandsaw blade comes coiled into 3 concentric loops, the trick to folding the old one up the same way has eluded me, I've done it once before after watching a video on Youtube, but it's a bit of a weird topological feat, which may appeal to any of you who enjoy a good puzzle.

I've got permission to cut a bit of Hazel, which I shall do on Friday, I spotted a lovely long straight bit about 3-4" diameter with smooth polished bark like gunmetal.
I'll probably get 4 staves from it, (two lengths each split in two) and might try to get a 'bark on' bow from it.
I expect I'll have some pics by the weekend.