My horn bow build-a-long

[Mafort]

It looks like it’s coming along

[bownarra]

No the location of the splice doesn't matter as it is in the core. The sinew does all the tension work - if not the bow would blow before even getting to brace height
Yes the tips look better now but as you say be careful about not having any bend in the sal area.

[DC]

Should there not be any bend(reflex) in the sal? Does that all come from the sinew shrinking? Should I modify my caul some more?

[bownarra]

Sinew shrinking doesn't give the bow much reflex at all. Most of the gained reflex comes from tying the string between the tips and increasing the reflex after each layer.
The sal should be straight to begin with.
Adam explains the reasoning behind not having reflex in the sal it is to do with separational forces between the layers.

[DC]

I sure seem to miss a lot in that book. Today is bend the real limbs day. I'll leave the sals straight.

[DC]

OK the real limbs are bent. It went very well I think, can't see any cracks. Time will tell. Now I have to wait a week. Not good at that

[bownarra]

Perfect

[DC]

Thanks

[DC]

How do you know where the apex of the kasan bend/eye is? I've looked through Adam's book and I can't find it. In the two bows he gives the measurements for he says where the kasan/tip bend is but nothing for the kasan eye.

[bownarra]

You establish your thickness taper so that the thinnest point is maybe 5 cm before (sal side) the apex. The apex is the middle/ highest spot of the curve
Take a photo of your core lathes, mark where you think it should be and I'll tell you if you are right

[DC]

So the apex of the sal/kasan bend is decided by the thickness taper(tiller?) more than where you bend the lath? So is the kasan/sal bend more of a hinge than anything else? I'll take some pictures and mark my ideas on it after I moving and have my coffee. Thanks

[DC]

OK here is a picture of the limb. From A-B is 10.5cm(4+"), from B-C is 19cm(7.5")and C-D is 45cm(17.75"). So point C is the one I'm confused about. I arbitrarily put it at the apex of the bend I put in the form. Doesn't that become the kasan eye or can I move it some by varying the thickness? Is there some size/length relationship between the tip, kasan and sal? I found a picture in the book(in the Ottoman Bows design section) that says the tip can be 6.5-12.5 cm long and the kasan can be 11-21cm and there is no dimensions given for the sal. This doesn't help at all. Everyone swears by this book and I just find myself swearing at it. He seems to leave out one or two dimensions in every discussion. Sorry, I'm just getting very frustrated with this whole thing. It's a good thing I have to wait for these limbs to dry. It will give me some time to try and figure this out.

[bownarra]

If you have total length and this length is divided into three sections, two of the dimensions are known therefore the third length is...........what you have left
It all makes sense once you have made a few
There is no set measurements for the parts, there is a fluid relationship between them depending on what you want the bow to do. Look at the table with all the old bow dimensions on so see how things vary.
No the kasan eye isn't a hinge.....it is simply the apex of the bend and 5cm or so before it is the thinnest part of the limb. You have marked the correct spot on your picture.
When you make your first bow you are still seeing everything with a beginners eyes, remember your first wooden bow? It may sort of make sense but as you gain experience you start to appreciate how all these factors come together to form the whole. You will also see that Adam hasn't missed anything out
Patience grasshopper

[bassman]

Wow. That is bow building at it"s best. I would love to see that bow finished and shooting. Excellent build along.

[DC]

Thanks Bassman. I'm still in waiting mode so I thought I would try my hand at making a groove scraper. I used an old cabinet scraper for steel. I had a bit of a chore getting it soft enough to file and then it warped when I hardened it but the screws pull it down flat. It's 16 TPI. I'm having a tough time seeing the teeth to get them even. Maybe I'll go buy a pair of reading glasses. I was using a magnifying glass but trying to file one handed ain't my thing. I didn't notice how uneven the teeth were until I took the picture . I still have to make the alignment tooth. I'll post a picture of it then. I'll have to play orthodontist with those teeth first though. I did a test scrape and even with the crooked teeth two pieces mesh quite well.