Monday, 4 May 2015

Thunderbolts and Lightning

I went up to the Walkern Village show on Sunday, there were a good few of us, all the "medievals" being dressed in their kit and showing their stuff. There was a have-a-go and I had my shave horse set up whilst working on that Yew stave and showing off Monkey Bow and his whistling arrows.

The thunder and lightning started and the rain lashed down. Fortunately we were under the cover of a big gazebo/tent thingy and people crowded in. There was one charming family, the guy was very interested in the bows and seemed to have a technical background, the youngest boy was in his mum's arms while the little girl was chatting away (to herself as much as anyone else!). She said she'd been in the woods and found a stick that bent like a this.... (she mimed drawing a bow) and then it turned into a canon! Excellent, wish I could find some of that wood.

Chatting to people is always fun when they are interested and one woman asked a very insightful question about do I do it all by eye or do I measure? I'd been sitting at the shave horse working the yew and she'd watched me flipping it over back and forth and eyeballing it. The reply was basically you can't make a self bow by numbers but it would be foolhardy to totally ignore any measurement. I showed some of my bows which had dimensional peculiarities.

One of the guys Andy who's heavily into the medieval, re-enactment etc and does loads of shows returned an old Yew bow that I'd made him way back in 2010 as a simple Yeoman's bow... The poor old thing had followed the string severely. I should really have taken a pic for a before and after, but suffice it to say I could get my whole fist between belly and floor when I put it down with the tips resting on the floor.
I said I'd re-furbish it and if it went bang I'd make him another bow.
It was never one of my best bows and the wood was odd, rather rubbery, it was from the underside of a long diagonally growing limb, nice and knot free, but compression timber.
Looking back at that post on my blog, you can see the tiller isn't perfect... yes, it's even, but it's bending too much at the grip. Interestingly, in those original pics you can see the difference between heart and sapwood. Now it's matured it is all one colour, the heartwood is behaving more like sapwood... interesting.

It was also made at a time where I was only just getting back into bow making after many years of ... well... doing what we all do.

I want to investigate it to learn more about the wood, so I've started by warming it and trying to pull it back straight... I could barely believe it! Normally it takes a good long time to get the heat into the wood to allow it to start flexing. With this I had barely wafted the heat gun over it for 5 minutes and I felt it starting to loosen up and bend.
I soon had it clamped down straight and I'm in the middle of heat treating it. I'll re-tiller it and see how it performs, I might even rasp off the belly and glue in a new heartwood belly if necessary.

I made some progress on the "ItalianYew" stave reducing the sapwood a fair bit, slow and steady wins the day.

Oh, yes, the Hazel Warbow got a bit of a trial and was left with one of the guys to try at full distance with heavy arrows. We were only shooting at 10 yards at the show for safety reasons... just as well as one of the marshals wouldn't be told that parking cars 40 yards behind have-a go archery with no back stop netting was a bad idea!
Fortunately there were no long overshots and the Warbow fraternity resisted the temptation to loose a volley up high and drop 'em through the roofs of the parked cars.
Just to show I'm my own harshest critic here's a pic showing the poor tiller. Lets see if I can improve it.

Update:- I've taken a good bit off the outers, and taken a pic on the tiller. It shows what 5 years of experience and a heat gun can achieve. Note the draw weight is 50# @ 28" which is I believe the original weight.
I've shown the tiller for each limb. The left (lower) being slightly stiffer (larger radius). The little deflex bend at the end of the right limb exaggerates the bend, and the black patch just left of centre on the right limb is another spot of natural deflex. I'm tempted to try and take out the deflex from the tips, but it's the wise man who knows when to quit while he's ahead.
The pics are at a rather low brace, which is a good thing to avoid over stressing the bow during tiller adjustments. I've since twisted up the string to raise the brace height and shot a few arrow from it. It shot 'em pretty much how you'd expect.


  1. Morning derek, could you please explain the relative merits of this type of tiller compared to say full compass if i have the terminology right the full compass is one even bend all the way through? Does this tiller give a smoother draw? better cast? keep up the good work, rgds Adrian

  2. Just my opinion of course:- This finished tiller is near as dammit full compass. An elliptical tiller or a Victorian style longbow tiller has a stiff section in the grip and the bend increases towards the tips. I don't actually like the term elliptical as it is not specific enough.
    The 'bad tiller' in the illustration is an ellipse! But elliptical tiller really means the longer axis of the ellipse is vertical rather than horizontal (like the bad one). I prefer arc or a circle tiller (full compass) as it gives more working limb* and thus less strain on the wood. The proponents of elliptical argue that due to the thicker wood near the grip it should bend less for equal strain. This all gets muddied by whether you have a non bending grip. On a bow of even limb thickness (say a pyramid style) then arc of a circle tiller is "right" in terms of stressing the material.
    The problem for a beginner is they overdo it and exaggerate elliptical tiller, it's all fairly subtle, which is another reason for liking circular. It's easy to do the CD test, hold up a CD or a plate in between you and the bow and judge the curve. Try finding an ellipse to hold up... and what ellipse? The term is too vague IMO
    * That's why I have never made a Mollegabet bow, short working limb with long stiff tips. It's hard to judge a good curve over a short length.
    I hope that makes sense.

    1. Pros and Cons:-
      I think elliptical is more efficient and faster as a target bow, but at longer draws the tips can be coming back towards horzontal giving a less smooth feel (it's all about the geometry). So for longer draw full compass, For target, or maybe flight with short arrows which are more aerodynamic a more elliptical tiller. I used to be scathing about Victorian bows until I say a load of 'em. They knew what they were doing.

  3. Ey up, thanks for that explanation, yep it all makes sense. my hazel and elder staves are ready for my attention on my next 18 days off from work next month. i am going to go for the full compass tiller in the hope that it will be more forgiving of a beginners attempts. I have your wise words on a piece of post it............ go slow and when in doubt drink tea! rgds, Adrian