Kviljos crab bows

Kviljo · Post by **Kviljo** » Sun Mar 21, 2010 7:23 pm

I've started making a crab bow from the measurements and drawings that Reto published a while ago. The cross sections will be shaped according to the Bedes drawings.

The seven core parts are prepared for glue up now. Hopefully I will be able to glue them together tomorrow.

I tried several times with different setups for bending the kasan pieces. I used birch - probably white birch, and all it did was collapse across the ridge on the back. Fibers lifted too much on the belly side too. Finally I gave up, and found a naturally bent piece of some kind of fruit tree.

The angle at the kasan eye was also hard to decide on. I hope it looks okay. I guess I will find out when the bow is finished and I can compare it to originals on pictures.

The grip is oak, the limbs birch, the kasan pieces some kind of hard fruit tree as mentioned, and the tips from birch. I cut the tips from a straight grained board, letting the tip itself have the best grain orientation while the wedge has pretty bad grain orientation. With sinew on the back, I don't think it will be a problem.

Any comments are very welcome

Dusan · Post by **Dusan** » Mon Mar 22, 2010 10:24 am

Hey , friend- congratulation- first bow looks like Turkish

Very short part between V splices in sal - to me.

Kviljo · Post by **Kviljo** » Mon Mar 22, 2010 2:27 pm

Hehe

I was looking through Adams book yesterday after I published the pictures, and made the same conclusion... But I don't think I will convert it into a turkish war bow, since they did not have the extra spliced in kasan pieces. (?) I will try to make the kasan angle closer to 90 degrees and straighten the tips slightly. That ought to make it more like a crab bow. ...I hope

The non-spliced center part of the sals are quite short. It is made according to Retos drawings though. Perhaps the grip splices are a bit too stretched. I don't think it will matter anyway. The core won't be thick at all in this one, as I'm hoping for a draw weight of at least under 70 pounds.

Dusan · Post by **Dusan** » Mon Mar 22, 2010 2:43 pm

Anyway - good looking bow now. Good luck .

Dusan · Post by **Dusan** » Mon Mar 22, 2010 2:49 pm

Look at the Russian collection- Andrew Hall post Ingo Simon collection vith bigest nombers "Crab" bows what ever i see !

Kviljo · Post by **Kviljo** » Mon Mar 22, 2010 9:02 pm

Thanks for the tip! Huge collection of goodies there!

I adjusted the angles a little tonight before I started glueing the parts together. When I clean up the core after glueing, I think it won't be too far from the original.

Dusan · Post by **Dusan** » Mon Mar 22, 2010 9:12 pm

Yes

.Better angels . Good work.

Kviljo · Post by **Kviljo** » Sun Mar 28, 2010 10:14 pm

These grooves may or may not be historically correct on this type of bow. As I am not an expert when it comes to glueing with hide glue, I think I might need the extra surface of the grooves to make sure the horns won't pop off when the bow is ready for tillering.

I found that my 1,5" broad grooved scraper was neither as effective or giving as good result as this four-thoothed scraper. The main advantage is that it is easier to file four teeth even, than filing 24 teeth

- plus it is much quicker to sharpen and much more effective to work with.

The core and horns are now drying from the first five coatings of very thin hide glue.

jkekoni · Post by **jkekoni** » Wed Mar 31, 2010 7:58 am

What is width and depth of the teeth?

I assume you made that tool yourself (and if not please tell where are they sold).

Kviljo · Post by **Kviljo** » Wed Mar 31, 2010 9:39 am

They are about 2mm deep.

A scraper and a small triangular file will give you as many of these as you will ever need

jkekoni · Post by **jkekoni** » Wed Mar 31, 2010 11:13 am

I think that the matching grooving affect in two ways.
1. It adds glue surface area
2. More importantly the material change is no longer instant, but happens
over distance.

I do not know about natural glues, but the general delamination with
epoxy happens not at the glue line, but in the material next to it.

I would assume that the matching grooves decease the likehood of such
thing happening.

Kviljo · Post by **Kviljo** » Wed Mar 31, 2010 4:07 pm

That might be it, but according to Adam, the matching grooves have not been used in the handheld composites before 1900. It is used in the european horn crossbows, though. But the constuction of those are quite different to the asiatic composites.

- so I'm not trying to match the grooves exactly, although they will match partly anyway.

I glued the horns to the core today, by the way. This was the fourth time, and the first time I wasn't completely overstressed by the process. With a lot of preparation and re-hearsing, it went very well. Pictures to come.

Looking forward to shaping the bow and starting to lay the sinew!

Kviljo · Post by **Kviljo** » Wed Mar 31, 2010 9:39 pm

jkekoni · Post by **jkekoni** » Thu Apr 01, 2010 8:14 am

I know that they may not have been used historically.

I am primarily intrested in 'things that can be done'...

BTW:
Isn't bow with so much iron so heavy and prone to fall on the side?
I think these are much easier to use: (providing the 50mm is enough)
http://www.clasohlson.fi/Product/Produc ... =134587814

with 2.90? they are dirt cheap too.

Kviljo · Post by **Kviljo** » Thu Apr 01, 2010 9:14 am

Yep, it is a bit unsteady, but the core is quite sturdy so it didn't bend. I hope it is still standing in my workshop, though.

I've been looking for some small C-clamps, but haven't been able to find any locally.