Tillering Thoughts
I was thinking it might be good to open a thread about the initial stages of tillering of the bow. The number of broken bows I've seen on this forum that "go" before they're even strung is alarming and heartbreaking! Some thoughts and questions to consider:
My self-bow success rate really improved when I started using the "never exceed the target weight of the bow when tillering" rule. Could something similar be done at the teplik stage? For instance, if you want a 60# bow, and it takes more than that to bend the limb to the teplik, you go back and scrape?
Could it be possible to heat the sals for the initial stages of tillering, then regain some of the lost reflex with a timar process?
Any other thoughts for us beginners to have a better chance at success?
Thanks!
My self-bow success rate really improved when I started using the "never exceed the target weight of the bow when tillering" rule. Could something similar be done at the teplik stage? For instance, if you want a 60# bow, and it takes more than that to bend the limb to the teplik, you go back and scrape?
Could it be possible to heat the sals for the initial stages of tillering, then regain some of the lost reflex with a timar process?
Any other thoughts for us beginners to have a better chance at success?
Thanks!
I am curious about this too.
With wooden bows I think that rule is a bit overdone but if it helps people attain a good bow I can see that it's a good thing.
With a composite the materials seem to focus on the fact that they are capable of taking so much more strain.
If a bow meant to be 50 pounds is breaking because it's too heavy initially, does that even make sense?
What would be different about a bow intended for pulling 70 pounds?
With a wooden bow we wouldn't hesitate to say it needs to be wider or longer or more evenly tillered.
However it seems like there are plenty of extremely high draw weight historic composites that are "too short, too narrow and too hingy" and they held up fine.
With wooden bows I think that rule is a bit overdone but if it helps people attain a good bow I can see that it's a good thing.
With a composite the materials seem to focus on the fact that they are capable of taking so much more strain.
If a bow meant to be 50 pounds is breaking because it's too heavy initially, does that even make sense?
What would be different about a bow intended for pulling 70 pounds?
With a wooden bow we wouldn't hesitate to say it needs to be wider or longer or more evenly tillered.
However it seems like there are plenty of extremely high draw weight historic composites that are "too short, too narrow and too hingy" and they held up fine.
Good idea to open this thread !
This is the crucial step of "near-art" as one writes ;-)
The force needed to initially open and string a composite is certainly higher than in the finished state. In my limited experience its quite difficult to estimate the definite drawweight from that..
I'd like to recommend "pre-tillering":
after the horn is glued to the core, one can cautiously flex the limbs (not to strung position of course) and tiller the wooden core to achieve limb balance and even bending in the area where it is intended. Plus in this way you dont loose horn (!). After the standard sinewing and with some luck, the bow will ultimately need only minimal corrections.
For the tepelik its important to fix the tip and press down the grip over the tepelik (just as shown in Adams book), not the other way round.
By heating, twist and even kasan area and limb balance can be corrected very easily, at the risk of loosing drawweight when heating the sal area. For beginners like me thats actually a very attractive method. "Arab archery" mentions heat for corrections of limb balance if I remember well. I cannot estimate how much drawweight is lost by heating the sal region. Its possible to regain some draw-weight with timar but do not overestimate that. Rather add sinew.
This is the crucial step of "near-art" as one writes ;-)
The force needed to initially open and string a composite is certainly higher than in the finished state. In my limited experience its quite difficult to estimate the definite drawweight from that..
I'd like to recommend "pre-tillering":
after the horn is glued to the core, one can cautiously flex the limbs (not to strung position of course) and tiller the wooden core to achieve limb balance and even bending in the area where it is intended. Plus in this way you dont loose horn (!). After the standard sinewing and with some luck, the bow will ultimately need only minimal corrections.
For the tepelik its important to fix the tip and press down the grip over the tepelik (just as shown in Adams book), not the other way round.
By heating, twist and even kasan area and limb balance can be corrected very easily, at the risk of loosing drawweight when heating the sal area. For beginners like me thats actually a very attractive method. "Arab archery" mentions heat for corrections of limb balance if I remember well. I cannot estimate how much drawweight is lost by heating the sal region. Its possible to regain some draw-weight with timar but do not overestimate that. Rather add sinew.
Hehe, who might that that one be? :^)Uli wrote:
This is the crucial step of "near-art" as one writes ;-)
Thanks for the comments and advice. Adam is certainly clear on the proper process for this, but there are so many failures on bows that look well made I'm quite nervous. I'm surprised no one else has made any comments!
Rob; I will take up your gauntlet. There is a lot of instinct in building and completing a hornbow. How to have good instincts without experience?
If your first hornbow is too strong or too reflexed then you are over ambitious. This is the same fault as not allowing enough time to cure. Ignore the calls to make a strong bow or a deeply reflexed bow.
The craftsmanship must be superb, the best you can muster; prototype, layout, glue up, materials, previous bow making experience. The bow must be proportional and perfectly shaped before sinewing. The construction must be unhurried and the curing time sufficient.
A bow should be heated before opening. As Uli says attach the teplek to the siyah first. The teplek will well support a good bow so proceed slowly but in one session. After some time in the tepleks reheat and string with the tepleks attached. After some more time slowly release the tepleks if all goes well and proceed.
An archer who makes and shoots a hornbow of ANY quality will receive the admiration of his peers.
If your first hornbow is too strong or too reflexed then you are over ambitious. This is the same fault as not allowing enough time to cure. Ignore the calls to make a strong bow or a deeply reflexed bow.
The craftsmanship must be superb, the best you can muster; prototype, layout, glue up, materials, previous bow making experience. The bow must be proportional and perfectly shaped before sinewing. The construction must be unhurried and the curing time sufficient.
A bow should be heated before opening. As Uli says attach the teplek to the siyah first. The teplek will well support a good bow so proceed slowly but in one session. After some time in the tepleks reheat and string with the tepleks attached. After some more time slowly release the tepleks if all goes well and proceed.
An archer who makes and shoots a hornbow of ANY quality will receive the admiration of his peers.
Thanks for the advice, Jack. I guess the margin for error is small - it's as simple as that.
The margin for error is small for us because we are trying to make something complex and very out of character with our times without an on site teacher. While visiting a Korean bowyer workshop, I saw an apprentice conditioning a bow do amazing things to it. It was like a Turkish massage for a bow. I did not know that a bow could take such treatment.
But the master was repairing a horn delaminate on a bow another shop had made. And I also came to own a dissected Korean bow in which the horn had not been completely glued down.
It is the equivalent of making a violin without an apprenticeship. The big difference is that you don't try to fold the violin in half.
But the master was repairing a horn delaminate on a bow another shop had made. And I also came to own a dissected Korean bow in which the horn had not been completely glued down.
It is the equivalent of making a violin without an apprenticeship. The big difference is that you don't try to fold the violin in half.