To groove or not to groove

Very nice, thanks for posting. Is this picture copyrighted by the museum?

The wood of grip is probably Cornelian cherry (Cornel, Cornus mas.) a type of very hard and heavy dogwood. The grooves are not matching as usual.

Adam

Hello Adam,


I don?t know if it?s copyrighted. I?ve got it years ago through a friend who visited the museum and was given it by somebody working there, if I remember well. I guess it should not be published in a book or magazine, though...

If the grooves are matched or not is dificult to tell I think:

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On one of the sections it seems to met hat they were sort of matched but not glued together very exactly ;-)

With the cornelian cherry you are right, I think!

JJ

Those grooves are as I think only for glue surface.
But more interesting is how they have use the wood, the cross-section.

Super ! Your photos help for many of us . Thank you . :idea:

Hello JJ!

This photo of a 15th century composite bow for a crossbow, shows what matching grooves look like:

http://i191.photobucket.com/albums/z111 ... ection.jpg

Thanks a lot for pictures, it is very good for bowyers. Do you have anothers?

Cem

Adam,

you have most experience vith building comp.turkish bows. When i see this pictures , its look like a maple wood, was not flat piece wood from big tree / which use most of us/ , but from litlle diameter 4-6 cm twig ?!? If it is, why is twig better , then very well selektion big tree wood ? I dont believ in chance .

It certainly doesn't appear flat in profile.

Not only flat. I rasping in final work in arm slitly round angel, but its evident from layer curvatur that it is twig.

On the matter of limb core wood being from a small diameter trunk or branch, there are at least a couple of practical reasons a bowyer might use such a piece. It is much less work to select a small diameter piece and work it into shape than it is to fall a tree with a large trunk, rive or saw it into planks, and then work it into final shape. Large diameter trees may have been earmarked for other uses as well....furniture, carriage building, ship building, structural beams for building construction etc., leaving small diameter saplings more readily available to the bowyer. I personally lean towards the economy of effort idea.

I am surprised at the use of the center heart for the grip for the reason in the picture, that it has split in the grip and split badly in the splice.

One also wonders how the center appears in both the grip cross section and the splice. Is there a reflex above the grip?

Yes, economy , less work etc. Its sound logical and this reason know everybody of us, but nothing from your post is about bow . All we building bows and start especilay vith all wood bows from litlle trunk, branch or thiny tring, but everibody know that this bows crack and broke first.Thats reason is why we try bigger min. 15-20cm diameter tree. Why turkish bowyer use litlle 5-6 cm trunk? :shock:

Turkish bowyers used small trunks - the "suckers" - straight branches grown from the roots or cut larger trees. The logs were harvested at the diameter about 7-10cm, maybe less. It is very likely the preferred wood was Tatarian maple which is a small tree to begin with. This method (coppicing) allowed for better control over the propertieties of wood, straightness and lack of side branches. From what I have seen, the younger, smaller diameter logs produce more elastic wood, easier to bend into shape for the core, so maybe this was taken into account as well.

This bow, with the crack in the splice and the grip does not seem to be particularly well made. I would think it was a broken bow, which explains the decision to cut it into section by the museum staff (I assume it was done there).

Adam

Thank you Adam,
but still is question. Its better then more straight grown from bigest maple tree ?This thin trunk is better for shooting , speed, long life of bow or i dont know- plasticity ??? So we , who try build turkish or another old comp. like mongols huns etc. may use young trunks from maple or birch wood ? I lost a lot of time , money and /maybe this is good for me -walking in forest/ energy searching the best bigger maple tree, and now - litlle trunk is good. :lol:

From pictures is evident , bowmaster must laying most sinew laers on right and left side vith flatened goal in the end .Maple is no flat - but flat surface is needed- sinew work like wood compensation . Sinew is maybe more available then good flat wood , or- litlle trunk is more efective bow wood , then i think... :roll:

As an experienced wood bowyer, I can say the as a general rule with most desirable bow woods, small section/younger growth tends to be more elastic and resilient than large mature old growth wood.

well , i carve couple wood bows too . If you mean "younger grows " somthing about 15-20cm diameter its tru. But 5-6cm ? Yes , its elastic , but if you reflexid in full circle often delaminatet and broke.

What is that red material on crossbows bow? Is that horn? It must be horn!!!

Hello Rapsod!

Yes its horn, the orange colour is from the flash during photography.

Hello everybody!


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I found that detail of a turkish bow on a photo I took in Karlsruhe. I think these groovings, which probably should keep the sinew safely on the concave side of the siyah, are quite remarkable. Or was it a typical feature?

best regards, JJ

Thank you JJ - graet pic !!!

very nice pix JJ! Thanks for sharing.
We'll discuss that groovings.

This grooving on the back side of core is typical. It can be as deep as on the horn side, or finer and more shallow. Definitely recommended for horn bowyers, since the adhesion of sinew is improved with grooving as well.

Adam

Thank you, Metin!

Adam: You think that the whole back of the wooden core is grooved like this? Wow, that?s really deep.... But definitely the sinew can?t get loose from this!

JJ

Grooving on the back provide more surface for gluing. I think grooving prevents the cracks on the width of the bow.

Cem

Yes, Cem is right. A crack on the core's back will not propagate across the limb so easily when stopped by the glue-filled groove, since the glue is less brittle than wood. The similar effect is known in the fiberglass/epoxy composites.

The entire backs were grooved like this.

Adam

That?s very interesting, Adam. Are many bows scored so deeply on the back? Must the wooden core/ limb in this case be thicker?

By the way, do you know the nature of the binding which is underneath the nocks? Is it rawhide? And I noticed a little piece of green material which is glued on the front of the bow tips. What is that? Coloured Horn, or maybe some stone???

JJ

Hi JJ,

the binding underneath the nock is sinew and the little piece glued on the front of the tips is coloured bone; could be to prevent the tips from damage. By the way, you find interesting discriptions about this bows in http://www.tuerkenbeute.de/sam/sam_waf/

Peter

Thanks, Peter. They look good these green bone pieces, anyway;-)

Your turkish bow replica that you posted some time ago, too!

My first try is waiting for the finish.......

JJ

the groove on horn and wood core it will reduce the force of them , so you can not make them thin and power cause you need groove it, it only is my guess.

adam, can you make a 80+pound hornbow without groove?

Green dye was used on ivory and leather as well as bone. Ivory is not as good a material as bone for tip inserts because of its weight, but I have seen one bow with large ivory inserts in its tips. See the Turkish bow in the Grayson Collection MAC 1994-0978.
http://database.coas.missouri.edu/fmi/i ... loadframes

Concave matched horn. 5,5 mm thick at middle of the sal.

Cem

thanks bede and cem

bede:maybe ivory and bone is a good suggest for the horn, i'm difficult use database in your link

cem:very interesting your picture, the horn quality look very fine

I'm sorry Jiao. When you go to the site you have to type the MAC number into the search field to call up the picture. I couldn't get a link to work straight to the picture.

thanks to bede you are not need say sorry, your first reply already is enough