A quick sinew vs core & horn thickness question (Ottoman
After receiving and reading Adam's book several times I have decided that it is better to make an Ottoman bow before I venture into somewhat unknown fields. I selected Cat. No. 1/1092 from his list of bows to reproduce. In his book Adam said that a beginner should look to make a bow composed of identical thicknesses of horn, wood and sinew. At the middle of the sal this bow measures 13.4mm thick, which would equal three 4.46mm layers of horn, wood and sinew. This seems like an awful lot of sinew to me. Is this correct or should I aim for a thinner ratio of sinew to otherwise equal ratios of horn and wood?
-Thank you in advance for your help!
-Thank you in advance for your help!
subtract 2-3mm for the cover and decoration from overall thickness
(if there is cover on both sides, otherwise 1-2mm)
(if there is cover on both sides, otherwise 1-2mm)
The thickness (1mm per layer) was already subtracted for the bows listed.
Yes, the 1:1:1 ratio is the safe option, but for heavy bows the sinew thickness will be excessive. I would use 3mm sinew for your bow and min 5mm horn (in sals).
Also, if this is your first bow, I suggest to reduce reflex in the kasan eye and make sure the radius is rather longer (gradual bend, not sharp). The tip bend should be sharp as usual. And make sure the sals are straight, not (or minimally) curved. The thicker horn and straight sals help to prevent the layers coming apart by reducing the stresses in the glue line.
Adam
Yes, the 1:1:1 ratio is the safe option, but for heavy bows the sinew thickness will be excessive. I would use 3mm sinew for your bow and min 5mm horn (in sals).
Also, if this is your first bow, I suggest to reduce reflex in the kasan eye and make sure the radius is rather longer (gradual bend, not sharp). The tip bend should be sharp as usual. And make sure the sals are straight, not (or minimally) curved. The thicker horn and straight sals help to prevent the layers coming apart by reducing the stresses in the glue line.
Adam
As 13,4mm total thickness will be a fairly heavy bow, I would reduce the thickness somewhat. At least for the first bow. Perhaps 5mm horn and 5mm wood, and then use 100 gram of sinew. - or, perhaps even go for 6mm horn and 4mm wood, pluss 100 gram of sinew. That way you will still have some horn to scrape if needed to tiller the bow. It would of course be even wiser to go for even thinner horn and core, and still use 100 gram of sinew... :) I was not that wise, so I would not blame you for not doing so, hehe :roll: