bows in progress

It would be nice if you wrote the dimensions also. Length, thickness, width of the parts, And what you think they will end up, at draw weight.
Lately I have had two broken kasan in hunting the mass at no bending parts.
I got the felling that low mass at kasan gives more then low mass at ear. Just by adding a few gram sinew at kasan drop efficency with 9%.

Very nice indeed.

Very nice. Especially the tatar one. I'd be interested in hearing their dimensions and estimated poundage too.

Redhorse, I think you have my book and the dimensions are all there. I simply wanted a 100+lb bows, at about 42in ntn length. I now aim at about 12mm thick and 30mm wide sal (measured at sal below the kasan eye) for bows closer to 120lb. Since the sinew thickness will be as usual about 2mm at the apex of the round core section, then the before-sinew thickness of core and horn now is about 10mm. Since I expect the bows to be closer to 120lb, than 100lb, I will work the limbs down a little during the tillering stage - first I will narrow the sides for less than 30mm to reduce the weight. If I see any problems with stability, I will make the sal a little thinner, below the 12mm, perhaps to 11mm, by shaving the horn bellies. When I reduce the width or thickness of sal, I make sure the reduction does not cause excessive bending in one area, but is spread out over the entire sal with the kasan eye bending a little as well. The kasan sections are all the time about 15-16mm thick (now before sinew they are 13mm thick). There will be slight bending in the kasan at full draw. I fully expect the short bows to stack beyond some 24 inches, with full draw close to 28 inches, but still the arrow speed should be good with flight arrows in the order of 2-3 grains per pound of draw weight.

The Tatar bow is an "average" bow I wanted to make for testing the performance of bows I measured in museums. The length ntn is 54 inches, the sal at middle is 16.5mm with sinew (now 13mm) counting the side ridges for these bows (true total thickness about 15.5mm). I try to keep the limbs bending as close as possible to the grip, since this design tends to stack too with longer 32in arrows. The kasan eye is here 17-17.5mm total. The bow will be quite heavy at the long draw and I am curious about the performance.

I should mention, the Turkish bows must bend at the kasan eye at full draw and the kasan should be somewhat flexible to distribute the stresses more evnly thorough the limbs. If this is not the case, and the only bending section is sal, then the bows will develop excessive string follow in sal. Bows in museums rarely exhibit such string follow, which means the stresses were not concentrated only at sal. As to the breakage or too much bending in kasan - the triangular core cross-section is less rigid than the round core section at sal. One has to be careful to maintain enough thickness there.

Adam

Thanks Adam, when you do the round core you have thicker horn and wood, 5+5mm? What mass do they have before sinew?
The 68lb bow with broken kasan was 290gram before sinew and now 355gram. The kasan did break because the short horn strip under kasan did come of, at brace both times. The sinew hold it at a bend down 50-70 degree so I just bend it back and glue on thicker horn and wrap it with sinew. In few days I know if second repair will hold.
I got to much bending in kasan :)

I do not remember the exact thickness of horn, but I try to keep horn no less than 4mm for heavier bows. The mass before sinew is around 280 grams now, although the tips have not been yet trimmed (probably about 250 grams after that).

Adam

Adam; These are so nice! Do you think that your technique of bending the limb and siyah in one piece would represent a more ancient technique than splicing on the siyah?

Hunn bows appear to have had continuous limb/siyah. -j-

Adam, great stuff as always. You?re going to supply a whole army!

Jack - the ancient craftsmen were just as practical as we are. If they had a piece of wood with suitable grain pattern and long enough, surely they would bend it in one piece. Why not? In some regions such wood may be hard to find - thus the need for joinery. Or, the degree of bending is too much for a particular style of bow . I do not think the presence of joints have much significance, other than the development of the technique.

Adam

Adam; The Hunn and early Mongol bows would not have needed a splice at the ear as did Turkic style because of the low angle. Layering of the bend at the ear would seem to be weaker joinery than V splicing. And with the addition of bone plates to Hunn bows, work time and weight would be a factor.

When I see a round cross section at the bend, some efficiency would be lost.

The appearance of the first bows with v-spliced ears is at about the same period of the emergence of Turkic culture ascendancy in Central Asia. -j-

Adam,
As usual your work looks outstanding.
Alan

Alan, just wait to see his book.

I am quite sure that it will be consciousness expanding in it's own right.
Just starting to build my Asian influenced archery and armour library sure that it will be a great place to start.
Alan

Adam:

Handsome bows, you are very fast :)
Do you make the grooves old style concave or flat? . Nowadays I tiller heavy bow, I found flat grooving is not helped the stability.

Cem

Immpressive work, and you're productivity is even more immpressive!!! I'd better get off my seat and get working, I must be lazy!!!

The Tatar bow has concave horn (non-matched grooves). The Turkish bows all have flat horn.

Horn is a little thinner in concave horn bows and the core is a little thicker. The bows are more stable, but tend to get more string follow in the limbs, because wood is not as resilient as the other materials. I think the thicker-cored wood makes good target bows however.

Adam

Adam:

How deep is your non-matched concave grooves( natural axis to horn) ? Do you try to make concave matced grooves? İt is much trouble, maybe waste of time.
Thanks.

Cem

Cem, the grooves were not as deep as in the matched ones. I think it is a waste of time to match grooves, although I still do it sometimes for bows over 80lb. The degree of concavity is sometimes really small in old bows and can be achieved by pressing hot horn over a slightly curved core.

Adam

Adam:

I think concave horn ease to use Tencik ,concavity helps to spread horn pressure . I tried pressing hot concave horn , glue gelled and dried so fast. İt is useless for glue. Maybe old bowyers glued after cooled horn.

Cem

Adam: do you mean that the Turkish bows don't have the combed grooves to attach the horn to the wood? Does this have any effect on the bow's performance?

Grooves are always present. Cem was talking about non-matching grooves (ridges in one part do not fit into grooves of the other part).

Adam

Adam and Cem,
Is there any evidence of bowyers binding hot horn to the core without the glue just to set the curves? I don't think this would work as a way to set the concavity, but I haven't tried anything like this. I think that if there was a two stage matching of the horn to the core that they would have used a form to set the concavity. I remember something about this in Klopsteg.

By two stage, I mean that the hot horn is bent to shape first and let set and then glued to the core.

Bede:

I tried binding hot horn to the concave core. Horn is need very high heat to fit the core so glue can not use in this stage. I bind the horn till it cold. After this stage I glued the horn to the core. I believe if the horn coated with thin glue there is no need two stage.
I think concavity of core is good for stability and prevent slide apart to horn when using tepelik. İn addition matching grooves is very hard to make in concavity. I see old bowyers use non-matching grooves in concave horn, it is very practical, I believe concavity is good only in thick core.. I know Adam have good experience about concavity.

Cem

Cem is right. I have used wooden forms to make the horn concave after reading Klopsteg (there should be a pic in the book) and have done it a couple of times. I think it can be an economical way to use horn, if only thin strips are available. Then the core can be made thicker for sufficient thickness of the limbs. The concavity in horn allows to gain normally no more than 2mm of thickness (not enough to bother I think, since horn is plentiful enough nowadays). The mechanics of the concave horn when the limbs are bent is not too clear, except that more wood thickness adds stability, since wood is the stiffest member of the laminate. It is also the least resilient, so the bow tends to acquire more string follow.

I also made horn concave if I wanted to utilize the hollow, alredy concave base section of horn, and it did not have enough thickness. Then the solid part of the strip is hollowed out to match.

Adam

Thanks to both of you for the information. What you have written makes sense and also fits in with what I have read about old bows. Most of the Turkish bows I have seen where the horn has been scraped away at the kasan for lightness, the core seems convex. I haven't seen many broken bows.

Adam, beautiful looking bows, thanks for the information.
I'm curious what kind of splices you used in the handle of the Crim-Tatar bow. It looks like there are at least 2 layers for the handle.

I used the usual style V-splice for the limbs with an added lamination on top for sufficient thickness. If I had a thick enough chunk of wood with the proper grain curvature, I'd use it too.

Adam

Adam, I see that you have added a wedge onto the tips of these bows. Have you seen such construction in old bows?