Author Topic: holly bow loosely based on x-1-3  (Read 1131 times)

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Offline stuckinthemud

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holly bow loosely based on x-1-3
« on: August 26, 2017, 05:20:26 am »
Hi Guys,
so I modified the x1-3 dimesions to fit a 66" deflexed holly stave and finally plucked up the courage to put a long-string on it.  Here is how far I've got, 16" on a long-string hanging down 6".  This is as far as I can draw it on the tiller stick, I'm gonna have to fit a pulley to get any further.  Question .  Is this showing positive tiller, and, since I've used a modified X-1-9 taper, should I try to get an even arc, or go with what I've got? Photos show unstrung and progress



Offline WillS

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Re: holly bow loosely based on x-1-3
« Reply #1 on: August 26, 2017, 06:30:00 am »
Depends where you're holding the bow on the tiller, how you hold a bow when you shoot and what you think is the best way to tiller a bow!  Plenty of good bowyers will just aim to make both limbs bend evenly at full draw in their own hand, while plenty others will worry about positive tiller, holding the bow just above center on the tiller and so on.  Just do what you feel most comfortable with. 

Personally speaking, I'd say you're at the point where you want to get it to full brace - especially considering that it's already deflexed.  Don't hang around using a long string as it'll just increase the set, lower the performance and take you longer to finish.  Nice to see holly being used as well - I've got a couple of big holly staves I'm hoping to get 160lb out of, so I'll be watching with interest! 

Offline willie

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Re: holly bow loosely based on x-1-3
« Reply #2 on: August 26, 2017, 09:53:39 pm »
Quote
Don't hang around using a long string as it'll just increase the set
Have you actually had that happen Will?, I have always thought that might be an possibility.

Offline WillS

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Re: holly bow loosely based on x-1-3
« Reply #3 on: August 27, 2017, 05:23:28 am »
Can't speak for anybody else, but when I ditched the long string a year or so ago, my bows have increased in performance drastically.  Less set, much more front end and better early tiller.  In my opinion the long string should be used purely to make sure a bow is ready to brace - and even then only on staves that might be deceiving.

Offline Del the cat

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Re: holly bow loosely based on x-1-3
« Reply #4 on: August 27, 2017, 11:17:51 am »
IMO.
Once the tips are coming back 6 or 7 inches you may as well brace it. To continue on a long string will just give a false impression of draw weight.
On a 66" stave I'd limit the draw length to 28", and if you are going to heat treat it, do it when you are back to about 20 - 24"
Del
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Offline FilipT

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Re: holly bow loosely based on x-1-3
« Reply #5 on: August 27, 2017, 01:27:42 pm »
Was 28" maximum draw of that particular bow found on MR? Also, was bow (yours and MR) supposed to be 40 x 30 mm tapering to 15 mm tips? What poundage do you expect?

Offline Del the cat

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Re: holly bow loosely based on x-1-3
« Reply #6 on: August 28, 2017, 12:21:00 am »
Was 28" maximum draw of that particular bow found on MR? Also, was bow (yours and MR) supposed to be 40 x 30 mm tapering to 15 mm tips? What poundage do you expect?
Impossible to answer... But
I can only find 2 bows in Weapons of Warre that are shorter than 70", the shortest be 68.75" and I think these may be incomplete as, in the text it says the shortest is 1839 mm (approx 72") so yours is shorter.
The arrows were have two main lengths, clustered around 31" and 28" so I think it's reasonable to assume the shorter arrows would be shot from the shorter bow.
Of course no one actually knows.
Del
PS, your post suggests you have scaled down the X1-3 dimension, in which case, presumably you should scale down the draw length too
PPS. Regarding tiller, I'd suggest you just have the stiffer limb as the lower, if neither is stiffer, then leave it be...
« Last Edit: August 28, 2017, 01:56:53 am by Del the cat »
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Offline Badger

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Re: holly bow loosely based on x-1-3
« Reply #7 on: August 28, 2017, 09:03:49 am »
  I can't figure out why you would get a false sense of draw weight from the long string. I get about the same readings on the long string as I do on the braced bow, slight difference but close enough. In the last couple of years I started increasing my time on the long string and for me I get less set. If a bow takes set and is tillered properly it simply means we were asking too much from the wood or the wood is not dry enough. Once I come off the long sting and go to full brace I don't go right to full draw, I work my way back up checking for weight losses as I go. 

Offline Del the cat

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Re: holly bow loosely based on x-1-3
« Reply #8 on: August 28, 2017, 09:44:11 am »
  I can't figure out why you would get a false sense of draw weight from the long string. I get about the same readings on the long string as I do on the braced bow, slight difference but close enough. In the last couple of years I started increasing my time on the long string and for me I get less set. If a bow takes set and is tillered properly it simply means we were asking too much from the wood or the wood is not dry enough. Once I come off the long sting and go to full brace I don't go right to full draw, I work my way back up checking for weight losses as I go.
With a warbow it can take over 100# to pull the tips back fare enough to brace it and this make you think you are way over weight... but then you get the string on at brace and you find the damn thing is nearly finished.
Maybe it's 'cos I don't look at draw length on the long string so much, because I don't trust it... just a matter of perception maybe?
This video shows what I mean...
https://www.youtube.com/watch?v=QGKt8bEa-Ig&list=PLBz2tD9476KRkSOSICLsc-zj5ADyPKLZB&t=29s&index=3
This post from my blog shows that the stresses on the bow are different between long and short string at the same poundage.
https://bowyersdiary.blogspot.co.uk/2016/01/yew-afb-long-vs-short-string.html
I s'pose we all have our methods and we tend to stick with what we know...
Del
« Last Edit: August 28, 2017, 09:48:00 am by Del the cat »
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Offline WillS

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Re: holly bow loosely based on x-1-3
« Reply #9 on: August 28, 2017, 11:33:01 am »
  I can't figure out why you would get a false sense of draw weight from the long string. I get about the same readings on the long string as I do on the braced bow, slight difference but close enough. In the last couple of years I started increasing my time on the long string and for me I get less set. If a bow takes set and is tillered properly it simply means we were asking too much from the wood or the wood is not dry enough. Once I come off the long sting and go to full brace I don't go right to full draw, I work my way back up checking for weight losses as I go.

That's interesting, as I'm almost exactly the opposite  :D

I never use a long string unless the stave is particularly awkward looking - weird dips of reflex or strange wonky bits - and simply make sure my tapers are as good as possible first.  It gets braced to full height at that point, and tweaked until the shape is right, then taken to full draw (or actually an inch or two less than full draw and shot at full draw only) the first time it's on the tiller in one pull, possibly stopping around 25" to do heat treatment or if I see something odd happening.

Personally I feel that the longer a bow is "tortured" on a tiller, drawn inch by inch and "exercised" the more the wood is being taught to prefer being drawn than being straight which is of course the opposite of what we want. 

I cannot possibly prove it however - I just think my bows have gotten better since choosing to abandon the long string and slow, creeping tillering that I was doing before!  It would be really interesting to compare performance in two identical bows, one tillered inch by inch and one tapered perfectly to begin with, and taken to full draw immediately.

Offline willie

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Re: holly bow loosely based on x-1-3
« Reply #10 on: August 28, 2017, 12:32:10 pm »
Quote
In the last couple of years I started increasing my time on the long string and for me I get less set.

Interesting observation Steve. Perhaps the different results can be attributed to differences in the way we implement the method? Would you ever pull to full design weight (on the longstring), to bring the stave to brace height? How far do you find yourself drawing out the bow on the longstring?

IIRC, I did some calcs once that indicated bending a stave to brace height with the full weight and with stiff unreduced limbs can overstress the center third of a bendy handle. I was suspecting that I had damaged the wood on a bow I was tillering. Not to the point of creating permanent set, but the slow-to-return hidden damage kind of temporary set.

Like Will and Del, I do not bend a bow much past brace height on the longstring, but I do reduce the weight I use to get the limbs back that far, if I am still making adjustments to tiller. I actually try to bring the bow to brace height with less than full weight, in order to leave the center third less stressed in the early stages of tillering.

Quote
Personally I feel that the longer a bow is "tortured" on a tiller, drawn inch by inch and "exercised" the more the wood is being taught to prefer being drawn than being straight which is of course the opposite of what we want.

I agree Will, at least for bows that are my own, and I can make tillering adjustments to,  whenever needed. For a reliable shooter to be used by another, I tend to exercise more as I go, and guess what I end up with is basically an overbuilt bow.

I have never considered that the "torture on the tiller" method is necessarily part of the long string method per se, but both are often presented together in some tutorials, so I can see where one might think they go hand in hand.

Offline Badger

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Re: holly bow loosely based on x-1-3
« Reply #11 on: August 28, 2017, 12:55:58 pm »
  Del, in the video the string was quite a bit too long for any kind of accurate read. I completely ignore tip movement, I am studying the shape. I don't got to full draw weight until I get the limbs bending even but from that time on I am at full draw weight on every pull. You are correct that stresses are different on a braced bow vs a long string drawn bow. I usually allow for that in my tiller shape.

   Willie if you pull a bow to full weight before it is bending even yes you could set the middle third of the bow. On a new bow I am watching the middle third very closely for movement until I get everything bending pretty good.

   Out of the dozen or so long bows I built over the last few months 1" of set was the worst I got. I had a couple I had to back off from target weight to avoid set. One I had a target of 120# and ended up at 100# because I started off with too much flex in the middle.

Offline Badger

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Re: holly bow loosely based on x-1-3
« Reply #12 on: August 28, 2017, 07:20:45 pm »
Del, I noticed you said it took about 100# pull to brace this bow, it didn't take 100# pull to brace it, only because your string was so long, with a shorter string it would have taken 1/2 that same pull. You start loosing leverage the moment you start pulling on a bow, thats the main reason the bow gets heavier, very little to do with the wood getting harder to bend.

Offline mikekeswick

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Re: holly bow loosely based on x-1-3
« Reply #13 on: August 29, 2017, 12:31:46 am »
Badger - you took the words right out of my mouth!
Tillering with a long string puts less stress on the stave than bracing too early eg. whilst the tiller may still be off (if the tiller isn't off at all then of course it is fiune to brace it. The whole idea of using a long string is that it allows you to see the bend at lower strain on the 'bow to be'.
Will you seem to like to exaggerate when you describe tillering with a long string.....nobody advocates torturing wood with one! I suspect you got better at making bows/tillering right around the time you decided to concentrate on getting your tapers correct pre bracing/not using long string tillering. As I just said a long string by definition puts less strain on the wood. If however somebody using one incorrectly then sure you could start inducing set whilst using one. but use one correctly and you should start to see less set than bracing early and potentially missing weak/stiff spots (that I agree will only be there if the taper is incorrect). Different ways to skin a cat.

Offline Del the cat

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Re: holly bow loosely based on x-1-3
« Reply #14 on: August 29, 2017, 01:57:07 am »
Del, I noticed you said it took about 100# pull to brace this bow, it didn't take 100# pull to brace it, only because your string was so long, with a shorter string it would have taken 1/2 that same pull. You start loosing leverage the moment you start pulling on a bow, thats the main reason the bow gets heavier, very little to do with the wood getting harder to bend.
Yeah, it wasn't a great example  :-[... the "long string" there was just my warbow stringer string.
For long string tillering I use my string adjuster (ring of aluminium) to give me a string that I can only just get on the bow.
Del
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