Primitive Archer
Main Discussion Area => Bows => Topic started by: dobson on April 17, 2013, 11:16:55 am
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Hey im a newbie to these forums, hope I might be able to get a straight answer
Before I took a break from bow making I built 3 English longbows all of which were poor to mediocre at best particularly when it came to tiller. Years later I have decided to return and despite my initial optimism I think I was a tad bit too enthusiastic and naive and soon ended up ruining an ash stave with a terrible hinge and almost comically bad tiller! having a look around I didn't realize how detremental using a long string can be if you use it for too long so ill make sure to be careful when I use it as much on my next bow but there's another issue I have encountered
I have never really managed to nail this down: I understand it is normal for ELB's to have a shorter bottom limb which is stiffer due to the handle grip.
However I have always done drastic work on the lower limb during tillering to try and get it to bend equally with the longer top limb is this right? or should the lower limb always be kept slightly stiffer than the top limb?
secondly when you place the bow on the tillering tree/stick should it be in the center or the upper 1" of the grip?
sorry if these questions seem stupid
Dobson
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Your first consideration when building an ELB style bow is to use the proper wood(compression strong) and/or the proper design(flatter cross section) for less compression srong woods.
The lower limb should be slightly stiffer than the upper and having an asymetrical design lends itself to that. If you have an easier time tillering a symetrical bow then build your ELB that way. Unless you will be judged by the thickness vs. with rules of a true EB I wouldn't worry about that.
I place my bows centered on the tiller tree and pull it from the center of the string but I do leave the bottom limb stiffer but only visually. I don't measure it.
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Most of what you're asking has actually recently been discussed here. (http://www.primitivearcher.com/smf/index.php/topic,39248.0.html)
In short: no, the lower limb does not need to be shorter and/or stiffer. Some people make the lower limb 1 to 1½" shorter, and tiller it to be slightly stiffer, but it's not mandatory. For your first few bows, don't worry about it and try to make both limbs identical (which is hard enough by itself!).
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For ELBs, I tiller them from the center. Makes it easier for me to see proper tiller. I let the bottom limb reveal itself by picking the stiffer limb.
Strangely enough, I seem to have the hardest time getting the tiller on ELBs proper. It's hard to get those long limbs bending nicely in an even arc, and takes me much longer to tiller than a flatbow with a riser. While I'm tillering, I keep thinking "circular... make it round."
You're right about the long string. I don't even use one. I floor tiller to low brace and then go from there. I get the middle bending a bit first, then slowly bring the tips around to keep the tiller mostly circular. After tillering, I make the arrow pass only 1" above center, so the bow doesn't become too unbalanced in your hand.
Pat's advice is very good... pick the right wood if you want a true narrow profile ELB.
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Personally I hang the handle of the bow from a strap in the dead centre, and pull the string from an inch above centre. This shows me exactly how the bow will look in the hand, and accomodates for the stiffer lower limb. Like Adb, I work the middle first (but not the actual handle - that only starts to move at 30" or so) and leave the tips thick and wide. I get 90% finished on the tiller, then reduce the tips to fit the horn nocks and in doing so the tips end up bending more or less how I like.
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Cheers for the quick replies and advice! That has cleared a lot up cleared up for me now.
Its probably worth mentioning that the ash bow I was building was a Victorian style bow with a riser
Speaking of bow woods the stave I have bought (came pre-cut to rough dimensions on a bandsaw) is of red elm backed with a thin piece of Ash. The bow is ready to be made into a full compass longbow (I refrain from calling it a Warbow because the i dont expect the draw weight to be high) will this combination work and should I aim for a more rounded or square cross section?
Thanks again
Dobson
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I believe that elm was typically used for ELBs as a secondary bow wood. You should probably build your bow with a slightly flattened cross section instead of the typically deep, rounded cross section of the yew ELBs.
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I suggest you trawl through my 'Bowyers Diary' where I've detailed the build of loads of ELBs along with some failures and some posts specifically about your question.
As a rule I support the bow where my the main force will be on my hand which is about centre of the bow (that's the base of my thumb) I pull the string from where my fingers will be. The bow is also allowed to rock on the tiller.
Have a look at this post where I reverse a bow on the tiller.
http://bowyersdiary.blogspot.co.uk/2013/03/tillering-symmetry.html (http://bowyersdiary.blogspot.co.uk/2013/03/tillering-symmetry.html)
You can go back to where I start that bow and see right through the build, I actually reverse it and the nend up turning it back again.
Quick answer is the lower limbs is generally a tad stiffer than the lower.
Data from the Mary Rose bows also supports this.
If you build the bow completely symmetrical the lower limb will probably appear weak.
The only bows I've made where the tiller shifted after some use had the lower limb go weak.
If you aim to build the bow5# over weight with a slightly stiff lower limb, you can always adjust it after it;s shot in for 100 arrows or so, if you build it spot on and the lower limb starts to look weak you'll end up way under weight by the time you have corrected it.
Del