First Turkish Bow Build

I'm not making any bow yet, but your drawing looks good to me.. is that 1:1 scale? And how do you find the bend radius, is there any formula? As for me, I've just traced from some unstrung bow picture and estimate all the major measurement from there.. :oops:

I read the book and in the chapter of "Design" Adam had measurements of an average large bow. I also studied about a dozen WIP in this forum and took dimensions off of my Grozer's Turkish bow. The thread that was the most helpful for me was from bheggeseth. Thanks to him he documented a lot of his process and I shall do the same. Yes the drafting is scaled 1:1

Should I reduce the angles (150 & 140) on my form by 5 degrees because the wood could/would spring back a bit?

Originally I was planning on building a traditional Turkish horn bow but I am going to experiment with modern materials first and then slowly get into the horn bows. I have been following several threads by bowyers building horn bows and it would take them years to complete one. Technically you can probably finish one in 9 months if nothing goes wrong. Limbs break, horn de-laminates, etc... and that is another 3-5 months setback. So I want to take a modern approach first and then slide into a very traditional approach after I have several bows under my belt. I know from other forums of primitive or traditional archery, they really do not like the F word (Fiberglass) so if this is not the right forum for fiberglass built bows, let me know!

This is going to be an ongoing thread so bear with me and if any of you bowyer out there see something I am doing that doesn't look right, let me know! So the first thing I need to do is make forms. These forms is what I will bend the limbs on to get the shape. I have added 5 degrees to each form for any springback of the wood. The forms are made of plywood that have glued, stacked and screwed together; then I glued photocopies of the forms on and cut them out. In the typical Allen spirit I didn't make 1 pair but I made 3 What can I say? You never know when you might need the other 2!
Each pair was then screwed together and shaped on my edge sander (opportunity to buy new machines).

[external image]

[external image]

[external image]

[external image]

[external image]

[external image]

If you are going to make a glass bow first in a Turkish style design make sure you you don't overdo the kasan eye angle or else you will get a very unstable bow. You will only need a slight reverse taper to stop it bending in the kasan. If may be a good idea for you to build a little deflex into the handle area as well. Glass bows don't like too much reflex. Look at the desgin of virtually all glass bows - r/d designs to some degree.

Thank you for your input! I actually have a Grozer that I can get some dimension from and another bow coming from Hungary soon.

I am done making the forms for the limbs and the tips. I wanted a flexible form that could accommodate different size wood and simple/compact. This is a combination of what I have found the different threads on Turkish bow building. The anchor at the end of the form is made of G-10 with 2 5/16" bolts holding it in place and a 3/8" bolt that will pin the wood against the form. What I have done is leave the 3/8" bolt a little higher so that I can remove the bolt and insert spacers as needed for different thickness of wood. These spacers will be made out of G-10; I don't care how much force the wood is going to produce, it isn't breaking or shearing the G-10.
Then I have completed the patterns for the handle out of micarta and a thin piece of G-10. These are the master templates for the actual handle of the bow. It is to size and I have 2 profile patterns: One for horn and one for fiberglass bows. Since the horn bow will have horn on the belly and sinew on the back, it would add an additional 6mm to the size of the grip so that is why one pattern is smaller than the other.

[external image]

[external image]

[external image]

[external image]

Very neat work!

I am done building all the patterns and now I have a better understanding of shapes and sizes and the relationship of the different parts to each other. Over the weekend I discovered that the Grozer bow I have been shooting is really his short Turkish bow; I was always under the impression that it was the larger bow. The short bow measures nock to nock 47.5" while the larger one measures 53". The dimension I got out of Adam's book are for the larger bow. Interesting thing is that would be the same size as Grozer's short bow. I made all my patterns pretty flexible so I can play around with different sizes of bows and since fiberglass has a completely different end result than horn, it might explain why Grozer never went with the more accurate bow size. From shooting his bow, I can tell you it is very challenging. The bow is fast as advertised, my arrows clock at 190 fps. But it is difficult to be consistently accurate. The distances I shoot have been from 15 to 45 yards and it takes a lot of concentration to get consistent accuracy. BTW I am shooting with a thumb ring; I tried 3 fingers with this short bow and I don't know how many arrows I lost!

[external image]

[external image]

Wow, that looks like precicse preparation and a well equipped workshop. Congrats to that and thanks for the documentation.

Allen Elishewitz wrote:

[external image]

hi Allen, the kasan eye had quite steep angle for fiberglass.. is this for horn?

This is for fiberglass. I am about to go through my forms one more time; I am not quite sure they are proper. I think I need to go bigger with the kasan eye instead of 7" diameter, I might bump it to a 10" diameter to soften that corner.
The kasan/tip bend is way too sharp; in Adam's book the average is 150 degrees and I have it way too much.
Yes these forms are for a horn bow which is my original intent; I am just taking a side trip with the fiberglass.

It has been a while; had this thing called "real work" that had to be done

I couldn't decide between a steam box and boiling the wooden limbs so after looking through different woodworking forums it seems that steaming the wood is the preferred choice. Probably because it is more flexible and can accept larger pieces of wood than boiling. So I am going to cheat and buy a Rockler steam kit instead of making my own. There are a couple of videos on YouTube of guys making their steam box for this kit so I got my plans and started making mine. Once the steam box was completed and I received my kit; to my surprise I found out I had made the box too big by 1000 cubic inch!!! So I had to disassemble the entire box and make it smaller. Now it is 400 cubic inch under the recommended max size so I should not have any problems.
I still should be able to get 12 1.5" wide limbs in the box. I am going to check my forms one last time before I cut wood and star making the bow.

[external image]
[external image]
[external image]
[external image]
[external image]
[external image]

Boiling is the way to go i'm afraid! I've tried both multiple times and boiling definitely works better. What you've got to realize here is that most steam bending applications just don't ask the same of the wood that bending a hornbow core does.
To make a boiling set up you can buy a fish kettle that is big enough or go to a steel fabricator and ask them to weld you up a simple box out of 1 - 2mm stainless. Mine didn't cost much and will last a lifetime. You will need two stoves (I use a double camping burner) to ensure a good rolling boil is maintained. This rolling boil over the full surface is important.
I'm sure steam can be made to work but boiling guarantees your wood all gets to the same temperature and the heat is well soaked in everywhere. I've wasted too many pieces of core wood on steam to use it again and good core wood is very hard to find!

I tried both, each method being applied for 1h, and didn't see much difference. Well, there is one: When boiling, the water gets brown (with lignin, I guess). There was much less of the stuff coming out of the wood when I steamed it. Not sure if this is a desideratum - just an observation I can share.

What thickness of wood have you bent Arry? Kiln dried or air dried.
What I said about boiling versus steam is in relation to 17 - 19mm thick wood and Turkish forms.
Boiled wood gets a better heat soak. Steam is too prone to having different heat levels in the same box. I've steamed wood then tested the surface temp with an infra red thermometer and there can be quite big differences with a steam set up. As long as water is boiling you cannot have that problem.

There is a thermometer at the door end of my box; the steam comes from the back end. As explained on a woodworking forum, 212 degrees is 212 degrees; the secret is getting moist heat into the wood. If I could have made a big pressure box that would probably have been the ideal but this is for fun and an experiment.
I can understand your point where boiling is that temperature throughout the entire water but if the steam box is done properly, I hope it would yield the same results. For the thick core 17-19mm wood I believe it is really important it has a good amount of time soaking in water prior to boiling or steaming.
For me the only part that is going to be a hassle bending, is going to be the tips because I am planning on making a 5 piece bow and the thickest parts are the tips. But there are ways around helping the bend as other makers on this forum have shown; relieving material at the corner of the bend.

Mike, both green (that was boiled and bent easily of course) and air-dried (steamed in a plastic tube). As to thickness, I don't remember which one of those was steamed: 14, 17 or 19mm.
Having said all that - I then bought a fish kettle and boiled the air-dried lathes that I bent last time. It's more tidy, so tolerance for doing it in the kitchen is bigger :)

Five piece core - then you will have no problem. Having the tips separate means that a lot of the stress of bending them is avoided. Bending a five piece core is a breeze compared to a 3 piece.
This is what i've been doing on my last few bows as well. I now tend to cut off 'grown in' recurves. Just look where branches come off the main trunk. As long as the section is about 4 inch diameter then there is enough wood for two tips and they are very strong as they haven't been weakened by heat. If the shape is a little off then it's only a tweak with heat to correct the shape.

That is why I chose a 5 piece, I felt it was going to be a less problematic build. Since the tip is the one more prone to breaking, I wouldn't want to go through the trouble of getting a nice piece of wood that is long for the tip and core to end up breaking it; it just seems a lot easier to replace the tips.