Author Topic: yew ELB and more  (Read 4943 times)

0 Members and 1 Guest are viewing this topic.

Offline AH

  • Member
  • Posts: 244
Re: yew ELB and more
« Reply #15 on: June 11, 2013, 07:40:06 pm »
I think you need a thicker, stronger, less strechy string...
stronger and less stretchy, yes, but thicker, I doubt it.
I find that thick strings always reduce cast, and also--I am using dacron here.
It is a well known fact, at least in the warbow community, that dacron stretches a ton on these heavier bows and you can see how low the brace height is on the big warbow I'm still working on (second to last photo on the first post) when the string is actually five inches shorter than the bow's nock to nock legnth :o! When I first braced the warbow with dacron it felt like rubber band and there was literally no brace height. ;D
As soon as I get my hands on some fastflight...

Offline WillS

  • Member
  • Posts: 1,905
Re: yew ELB and more
« Reply #16 on: June 11, 2013, 09:26:19 pm »
Just a quick note - and I'm by no means an expert so take this with a pinch of salt but I've encountered this issue when working on warbows myself - when you say the big warbow is using Mary Rose dimensions, does that mean you took your unworked stave, and drew out the profile of a finished Mary Rose bow on the front and sides, then cut to those lines? 

The reason I ask is that I've tried that before, and what tends to happen is that the tips are always way too thin and narrow early on.  If you rough out an untillered bow to the exact dimensions of a finished bow, the tips will of course be tiny in comparison, and all the stresses and strains of tillering will be focused straight onto the tips, rather than the whole bow.  This leads to hinges and whip-tillered bows instead of nice full compass shapes. 

If you're working to a Mary Rose bow as an example, cut the front profile out leaving the tips fairly wide - say 20 - 25mm instead of the 12mm on the finished bows, and much thicker than the bow you're copying.  Tiller the bow so that the tips don't even start working until it's 90% finished, then narrow and thin the tips down to get the limbs to complete the full compass.  This will avoid any nasty hinges and whip-ends which you may be encountering by trying to copy a finished bow. 

The reason the tips on warbows can be so thin is that by the time they're reduced the rest of the bow is already doing a lot of the work, and the wood has been taught to bend and stretch and share the strain.  At this point, the tips don't really take much more stress, whereas if the bow is huge and untillered, but the tips are almost at the finished dimensions, you're asking them to take 100# of draw weight just on the tips.  It's even more amplified when tillering early on, by using the long string.  A long tillering string leads to whip-ended bows if you use it for too long during tillering, so combine this with thin tips and it's a recipe for disaster.

Of course, you may well already know all of this, in which case ignore it completely and hopefully it'll help somebody else out reading this at a later date!

P.s. have you read Cornwell's latest book, "1356" yet?  It's incredible!  Easily his best so far.  I enjoyed it even more than "Azingcourt"!

Offline AH

  • Member
  • Posts: 244
Re: yew ELB and more
« Reply #17 on: June 12, 2013, 12:13:37 am »
Just a quick note - and I'm by no means an expert so take this with a pinch of salt but I've encountered this issue when working on warbows myself - when you say the big warbow is using Mary Rose dimensions, does that mean you took your unworked stave, and drew out the profile of a finished Mary Rose bow on the front and sides, then cut to those lines? 

The reason I ask is that I've tried that before, and what tends to happen is that the tips are always way too thin and narrow early on.  If you rough out an untillered bow to the exact dimensions of a finished bow, the tips will of course be tiny in comparison, and all the stresses and strains of tillering will be focused straight onto the tips, rather than the whole bow.  This leads to hinges and whip-tillered bows instead of nice full compass shapes. 

If you're working to a Mary Rose bow as an example, cut the front profile out leaving the tips fairly wide - say 20 - 25mm instead of the 12mm on the finished bows, and much thicker than the bow you're copying.  Tiller the bow so that the tips don't even start working until it's 90% finished, then narrow and thin the tips down to get the limbs to complete the full compass.  This will avoid any nasty hinges and whip-ends which you may be encountering by trying to copy a finished bow. 

The reason the tips on warbows can be so thin is that by the time they're reduced the rest of the bow is already doing a lot of the work, and the wood has been taught to bend and stretch and share the strain.  At this point, the tips don't really take much more stress, whereas if the bow is huge and untillered, but the tips are almost at the finished dimensions, you're asking them to take 100# of draw weight just on the tips.  It's even more amplified when tillering early on, by using the long string.  A long tillering string leads to whip-ended bows if you use it for too long during tillering, so combine this with thin tips and it's a recipe for disaster.

Of course, you may well already know all of this, in which case ignore it completely and hopefully it'll help somebody else out reading this at a later date!

P.s. have you read Cornwell's latest book, "1356" yet?  It's incredible!  Easily his best so far.  I enjoyed it even more than "Azingcourt"!
Hi Will,
I know the dilemma you describe too well. :-[
When I said "Mary Rose Dimensions", I meant that it wasn't a MR copy, i was just using the dimensions as a reference. I actually laid out the bow on the stave two millimeters wider than the actual MR bow just to be safe during roughing out, and then I narrowed it down as I tillered. As for the tips, what I do now after that nasty experience with my first yew bow and whip-tillering, I leave the tips wide-say about 3/4" wide-until I have the bow bending around, say, 18 or so inches on the tiller, then narrow. by now there isn't really a chance of the bow becoming whip-tillered from prematurely-narrowed tips. 18" is when I took a break from tillering that bow and did the horn nocks.  ;) then proceed with tillering. at the same time when I narrow the tips, is also when I take out a set of calipers and start narrowing it down closer to the MR dimensions. I take a measurement along every inch of the stave and compare it to the MR measurements.
Concerning long strings,
personally, I hate long string tillering because it used to screw me up so much, but I still do it because I have not figured a way out to not blow bows up bracing right after floor tiller. If you remember a while back when I posted my first hackberry bow, it got sort of whip-tillered cause I lingered on the long string too long. Now when I tiller with the long string, I use a string the same legnth of the bow or even a whisker shorter so that I have to stretch it to get it in the nock--not quite a brace, but it doesn't play the same tricks on your eyes as a longer string.
But take all what I'm saying lightly, cos I still consider myself a newbie at making bows. (actually, when I compare my bows to Del's or Pearly's or Blackhawk's, I just feel plain laughable... ;D)
Here are the MR dimensions I'm using, I got it from this 110# warbow on PP
http://paleoplanet69529.yuku.com/topic/53298/MR-Replica-with-alot-of-knots#.UbfibvmThRZ
80"
W D

UL

11,5 11,5

17,0 16

21,5 20

25,0 22,5

27,5 24,5

29,0 26

30,5 28,5

32,5 29,5

33,5 31

34,0 31,5

34,5 33,0 Center

LL

35,5 33

34,0 32,5

32,0 31,5

31,0 30,0

29,5 28

27,5 26

25,5 24,0

22,5 21

17,5 16,5

13,0 12,0

Offline AH

  • Member
  • Posts: 244
Re: yew ELB and more
« Reply #18 on: June 12, 2013, 12:16:13 am »
Just a quick note - and I'm by no means an expert so take this with a pinch of salt but I've encountered this issue when working on warbows myself - when you say the big warbow is using Mary Rose dimensions, does that mean you took your unworked stave, and drew out the profile of a finished Mary Rose bow on the front and sides, then cut to those lines? 

The reason I ask is that I've tried that before, and what tends to happen is that the tips are always way too thin and narrow early on.  If you rough out an untillered bow to the exact dimensions of a finished bow, the tips will of course be tiny in comparison, and all the stresses and strains of tillering will be focused straight onto the tips, rather than the whole bow.  This leads to hinges and whip-tillered bows instead of nice full compass shapes. 

If you're working to a Mary Rose bow as an example, cut the front profile out leaving the tips fairly wide - say 20 - 25mm instead of the 12mm on the finished bows, and much thicker than the bow you're copying.  Tiller the bow so that the tips don't even start working until it's 90% finished, then narrow and thin the tips down to get the limbs to complete the full compass.  This will avoid any nasty hinges and whip-ends which you may be encountering by trying to copy a finished bow. 

The reason the tips on warbows can be so thin is that by the time they're reduced the rest of the bow is already doing a lot of the work, and the wood has been taught to bend and stretch and share the strain.  At this point, the tips don't really take much more stress, whereas if the bow is huge and untillered, but the tips are almost at the finished dimensions, you're asking them to take 100# of draw weight just on the tips.  It's even more amplified when tillering early on, by using the long string.  A long tillering string leads to whip-ended bows if you use it for too long during tillering, so combine this with thin tips and it's a recipe for disaster.

Of course, you may well already know all of this, in which case ignore it completely and hopefully it'll help somebody else out reading this at a later date!

P.s. have you read Cornwell's latest book, "1356" yet?  It's incredible!  Easily his best so far.  I enjoyed it even more than "Azingcourt"!
Oh, and concerning Cornwell's books,
I have not read "1356" yet, but it's on my to-read list. I have only read "Agincourt" and "The archer's tale", and just ordered "Crackdown". I do really want to read 1356 soon though, I have heard good things about it :)

Offline WillS

  • Member
  • Posts: 1,905
Re: yew ELB and more
« Reply #19 on: June 12, 2013, 07:30:55 am »
Before you read any of the others, read the Thomas Hookton trilogy, Harlequin, Vagabond and... The other one that I've forgotten.  It sets up the 100 years war and features more about the making of bows and the training than his other books.

Offline AH

  • Member
  • Posts: 244
Re: yew ELB and more
« Reply #20 on: June 12, 2013, 01:55:59 pm »
Before you read any of the others, read the Thomas Hookton trilogy, Harlequin, Vagabond and... The other one that I've forgotten.  It sets up the 100 years war and features more about the making of bows and the training than his other books.
Yup I've read Harlequin, I think the american name is The Archer's Tale. Vagabond is on my list. ;)