Dimensions of a Yumi
Hello everybody,
I would like to make a Yumi like bow, just a litte bit shorter for mediterranean release with 45# at 27" draw hight.
My problem is, i?m not able to find some measurements of a normal Yumi:
Length of the upper and lower limp, whith and thinkness and even the taper of the core,:?:
can you guys helb me with that problem ?
Thanks for replies,
Greetings ,
Sven
I would like to make a Yumi like bow, just a litte bit shorter for mediterranean release with 45# at 27" draw hight.
My problem is, i?m not able to find some measurements of a normal Yumi:
Length of the upper and lower limp, whith and thinkness and even the taper of the core,:?:
can you guys helb me with that problem ?
Thanks for replies,
Greetings ,
Sven
What about the Club in HH? Isn`t there a bow intersest, to be found? Or don`t you know about the Kyudo cclub in teh Hansestadt?
I guess you mean the Alster Dojo in Veilchenweg
I have been there a year ago to watch the enteki championship and I?m going to take part at the kendo-edukation in september.
But i need information from experienced bowmakers. They know what I?m talking about , know about problems and tricks and stuff like this.
The comunity of Yumi making Bowyers ist so much larger in here as in the german foren.
Last week I mett Jaap Koppedrayer in Southgermany, but i?ve been so impressed by his work, that I forgot to ask him some questions about.
But thank you for yor reply .
MfG Buechse 82 ( FC )
I have been there a year ago to watch the enteki championship and I?m going to take part at the kendo-edukation in september.
But i need information from experienced bowmakers. They know what I?m talking about , know about problems and tricks and stuff like this.
The comunity of Yumi making Bowyers ist so much larger in here as in the german foren.
Last week I mett Jaap Koppedrayer in Southgermany, but i?ve been so impressed by his work, that I forgot to ask him some questions about.
But thank you for yor reply .
MfG Buechse 82 ( FC )
In my holidays from working I started to build the Yumi and here it is .
The bow stil need some finish and some rattanwrappings.
It shoots nice and fast, even the drawweight ist not so high as I want, but so what.
Greetings Sven
The bow stil need some finish and some rattanwrappings.
It shoots nice and fast, even the drawweight ist not so high as I want, but so what.
Greetings Sven
Nice yumi man!!! Where did you find shape of unstrung yumi? I think that you could reflex it a little more. I think part above handle is too straight.
thanks a lot, and you are right, the next time I will reflex the part right above the handle much stronger so that it will be slightly curved foreward when strung up, but so what, best way to learn is from mistakes.
I found the unstrung form in the first link you gave to me.
I printed it and handdrawed it in the right scale. So I get a 2,30m form to bend the Yumi while tied up, wedged and glued.
After glueing the bow had a reflex from 39 cm , but after shooting it was just by 25 cm .
next time i will reflex it to 45 cm .
I even made so mistakes with the bamboo, wrong direktion of the nodes and some other little things, but over all, I?m happy and proud of the result.
MfG Gunsmith
I found the unstrung form in the first link you gave to me.
I printed it and handdrawed it in the right scale. So I get a 2,30m form to bend the Yumi while tied up, wedged and glued.
After glueing the bow had a reflex from 39 cm , but after shooting it was just by 25 cm .
next time i will reflex it to 45 cm .
I even made so mistakes with the bamboo, wrong direktion of the nodes and some other little things, but over all, I?m happy and proud of the result.
MfG Gunsmith
Hi Sven,
Congratulations to your Yumi!
To the reflex above the grip: its normal and even necessary this reflex gets lower after first bracing and drawing. Before shooting this hight must not be more than 25cm and not less than 12,5cm. If its higher and you shoot with the technique used in Kyudo, it can happen the bow throw off the string and the bow can be demaged. If too low, the Yumi is week and has to rest unbraced in a humid climate (f.e. bathroom), until the reflex gets more again (can last a bit).
Yumis used in Kyudo even have a small reflex direktly above the grip, called "Do", when the bow is braced; so shooting is much smoother and there is no handshock, because there are two points where the bow has a neutral and not swinging zone, one is the grip. An other possibility to solve this, is to make the Yumi thicker in this part.
Japanese culture is very impressed by nature, so their craft is easy to understand: the Yumi is built like the bamboo is grown, that means the bamboo is used in the same direction (lower tip = ground, upper tip = sky). Usual the back-bamboo has 7 nodes and the belly-bamboo 6, so back and belly divide in half the distance from node to node, the best solution for the durability of the bow.
Continue much luck
Peter
Congratulations to your Yumi!
To the reflex above the grip: its normal and even necessary this reflex gets lower after first bracing and drawing. Before shooting this hight must not be more than 25cm and not less than 12,5cm. If its higher and you shoot with the technique used in Kyudo, it can happen the bow throw off the string and the bow can be demaged. If too low, the Yumi is week and has to rest unbraced in a humid climate (f.e. bathroom), until the reflex gets more again (can last a bit).
Yumis used in Kyudo even have a small reflex direktly above the grip, called "Do", when the bow is braced; so shooting is much smoother and there is no handshock, because there are two points where the bow has a neutral and not swinging zone, one is the grip. An other possibility to solve this, is to make the Yumi thicker in this part.
Japanese culture is very impressed by nature, so their craft is easy to understand: the Yumi is built like the bamboo is grown, that means the bamboo is used in the same direction (lower tip = ground, upper tip = sky). Usual the back-bamboo has 7 nodes and the belly-bamboo 6, so back and belly divide in half the distance from node to node, the best solution for the durability of the bow.
Continue much luck
Peter