2 nd Turkish hornbow - progress

Here are some pictures of where I am upto on my "nd attempt at a hornbow.
I have finished the grooving of core and horn strips now and am ready to start the sizing process.
Hopefully I should be ready to do the glue up in a day or so.
I am still trying to decide which way to clamp the horn to the core. I have tried the traditional rope method, rope and wedges and inner tubes. I think I will try practising them all again before I start to size. Then the easiest/fastest method will be chosen.
At the moment I only have sinew and hide glue - no isinglass. How hot does the workshop need to be to slow the gelling down on these glues? I may have to do it inside when there is no mrs about!

Mike, 12deg C. is rather low. I keep my shop at min. 16, plus some local heat for these jobs. And let the bow dry inside as well - it will not dry well at 92%RH.

Adam

Yes I will be bringing it inside. Nothing dries here at the moment unless it's inside! I will be starting the sizing process on core and horn today. I think i've decided on using the traditional rope method for clamping them.

great grooving man, did you make the grooving tool yourself? it looks perfect. like the teeth are not pointed but flat, leaving a full sized (1mm?) channel at the bottom of the groove, rather than a point. i'm almost at that stage and i want to do it right.

Thanks, yes I made it myself. Just like in the book I got an old scraper and a 14 tpi saw blade, clamped them together and filed out the teeth on the scraper to match the blade. Then make a single tooth out of a piece of steel, fixed it to the scraper with a small nut and bolt so that it projects by 1mm or so and can be rotated out of the way.
I think the key to cutting the grooves straight is cutting the intial guide line perfectly straight. Just take your time with it, I used a very fine cut tenon saw and a piece of thin steel as a straight edge. Once that is right it's just a case of going slowly until all the grooves cut to 0.5mm or so then they guide the scraper well. Oh and it's worth using a good quality HARD scraper - even though they take a lot longer to file the teeth into!

thanks Mike

i'll definitely make one. I can't put it off any longer. I'm kinda nervous to tackle these hornbows because it's a totally new bow construction to me, and water buffalo don't grow in Canada.

I hope this one works out for you with no delaminations.

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Well i've got the horns glued on now...but I think I have induced some twist. It not excessive and i'm hoping there is enough material there to get a straight bow from!

I think the problem (twisting) occured because my core is pretty thin- around 15mm.
I want to laminate another piece of wood maybe 3mm thick to the core. Probably starting around mid kasan through to the end of the tips.
I am going to steam it then bend around my core forms. I will be using hide/sinew glue and am wondering how many coats of thin glue are needed for the best bond between woods. Also I am not sure which type of wood to use. I have more cherry (used for the core), ash, wych elm, kiln dried maple, hop hornbeam, osage and yew. I am mindful of not adding too much weight at the tips but of course I want the tips to be totally rigid.
Any advice welcome. Thanks

Mike, 15mm is enough for the whole of kasan (and with the sinew it may even be too thick). I would just add a wedge onto the back of the tip to increase the thickness to 2cm at the nock.

I have seen a damaged old bow, where the inside (the back side)of the core at the tip bend was scooped out to be filled with sinew. Sometimes, probably to increase the thickness, a piece of bone was added to the back of the tip at the nock.

Often people make the kasan/tip bend very thick. It is not needed, since the stresses there in the short-tipped bows are small and the bend will never open.

Adam

Thanks for the advice, that is very intersting about scooping out the back of the tips, maybe the tip bend had damaged the wood there when bent and the sinew was insurance against any more possible damge.

Sorry Adam but do you mean the actual 'back' of the bow eg. sinew side or the 'back of the tips' eg. belly side? I'm presuming the belly side otherwise any tension force would be working at the join (giving a stress riser effect).

I meant the back side (the sinew side) of the base of the tip (at the bend). Perhaps "scooping" does not accurately describe the process.

Such thinning of the core helps to create the sharp bend there. I tried that and it works. It is enough to reduce the thickness (on the back = the future sinew) side of the core lath. Basically, the tip is kept 2cm thick, then the core tapers down (again on the back = sinew side) by a few mm over about 2cm distance, then remains of even thickness for the rest of kasan and sal. A lath thus prepared will bend right after the thicker tip section, forming the required sharp bend. At the apex of the bend the wood will be of the same thickness as the rest of kasan, while the thickness grows rapidly towards the tip. The transition is then filled with sinew.

Adam

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When I took the ropes off after horn clamping there was quite some twist in the limbs. I think I need more practise with this method. Fortunately I had just enough material to be able to get a straight bow out of it but only just! I also had a problem when I reduced the horns down to strips ( a crack on the side of horn went quite far into it ) and only just had enough material here as well. Phew :lol:
Anyway I have added a 2mm piece of hickory to the tips to make the depth upto 17mm. As Adam advised I had enough material in the kasans so didn't have to add any wood here.
I have added the first layer of sinew now, it is only 1 - 2 mm thick and i'm hoping it will be dry enough in around a week to add the next layer on. This 2nd layer will be mainly to make the sal flat and the overlaps onto the belly and thicken the grip. I aim to make this layer 1mm thick apart from the edges which will need to be thicker. I am wondering exactly where to end the sinew when I reach the tips? Is it worth putting a little sinew around the tip bend and onto the tip to strengthen/protect the bend? Also when adding the second layer I presume I will need to size the previous layer but what concentration of glue should I use? 10 -15% ?
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• Mike
  I also fear a twist in the limbs. use two vises. although sal was only 10 mm thick, was glued temporarily piece of wood for stability. there was no twist.

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I think it is suggested in the book that one can correct any twist after glueing, by simply twisting the limb in the opposite direction. A setup like that, with two vices, looks quite handy though. :)

Ah ha! Excellent idea Pazuzu, I can rig a set up like this no problems.
I noticed the twist right after binding and thought I had straightened it out, however when I went back to it the next day it had returned.
2nd sinew layer today is going on today.

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The last of the sinew is on now and the waiting starts...patience....[/img]

I have been making this bow to the dimensions in Adam's book for the 48 inch 60 - 70 lbs bow. I have just measured the final thickness and it's 1mm too thick everywhere on the sal and kasan.
Will the sinew shrink at all? It has been kept in around 50% humidity, with a weeks drying time in between the 3 layers I have put on. Is it pretty much rock hard now would be fine to file if necessary. I think it would be best if the outer layer is left fully intact. I guess I can always burnish it with glass.

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Well I couldn't wait any longer :wink:
I have only had to remove a shade of twist from one of the kasan's to get it to brace height - between 6 -7 inches in these photos. It is stable at brace but is showing a little more twist in the kasan eye. This goes when the tip is held overcorrected for a few seconds, however if it is unstrung and then strung the twist is visible again so I guess a little heat is going to be needed to remove it permanently.
My only other problem is that this bow is far too heavy for me to draw properly.... :roll: as it stands...
Falling back on my selfbow experience - if I had made a bow too heavy I would reduce both the width and thickness to keep the same efficency and lower the draw weight. With this bow the sinew is the widest 'component' and I don't really want to touch the width (stability!), so that leaves me reducing the thickness. This is no problem but if I reduce the horn thickness I will have to take off the sinew belly overlaps to 'get at' the horn. Is it essential to have the sinew overlapping onto the belly whilst carring on tillering the bow?
Also what do you guys think of the shape at brace? I feel like i'm learning to tiller all over again!

Great job Mike, congratulations.

Re: reducing the weight. I would first reduce the angle at the kasan eye a little which will drop the weight and improve stability. At the same time the twist in kasan can be corrected. If it is still too heavy, then the sides of horn can be filed to make the belly round (or, say, rounder than it is now), until you reach your weight, but try to keep the thickness as it is along the centre of the limb. While you do that, the bow should be exercised by drawing almost to the full draw to see if the limbs are balanced. If not balanced, then a little scraping will be needed. After all that, the bow almost certainly will reach your desired weight (plus about 5lb to account for the drop of weigh in use).

Of course, this is all assuming the sinew layer is flat and smooth.

Adam

Nice looking bow Mike.What a pity -waiting only fue weeks :(

Awesome!! :D

I hope you are planning on making some flight arrows for it 8)


How long did you wait for the final layer of sinew to dry?

5 days...? :lol:

Thanks a lot for the advice Adam it is appreciated. I will be carrying on with it tomorrow and will do as you say. The humidity is very high here right now probably 90% in my workshop so I am slightly worried...however I am storing the bow inside for longer than it is in the workshop to give it a chance :?
After making lots of wood bows this is an interesting experience to say the least - I can see me making many more of these bows, even if I do live in a shocking climate for them! It's amazing to see the bend that is achievable with these materials.
Dusan - I hear what you are saying :wink: don't worry I understand the consequences and am prepared for more string follow, in a way I would prefer this bow to be easier to string and I don't really mind the loss of performance in this one. My next bows will be given much much longer to dry fully.
Kviljo- thanks and yes I already have a good selection of flight arrows to try - it will certainly be interesting to see how this bow does. My best shot so far was with a 64lb @ 25 sinew backed juniper recurve, 54inch ntn at 365 yds. The marker is still in the field taunting me to beat it....

Dont worry Mike :lol: , its more mi frustration from long waiting , than reproach to you :oops: Evan past 10 years working on this bows i am so frustrated when waiting in new generation bows. And havent your courage opening -and maybe lose quality such bow quickly.
I am big idler and when i force miself to work than i try made all right way.

mikekeswick wrote:

Kviljo- thanks and yes I already have a good selection of flight arrows to try - it will certainly be interesting to see how this bow does. My best shot so far was with a 64lb @ 25 sinew backed juniper recurve, 54inch ntn at 365 yds. The marker is still in the field taunting me to beat it....

Ahh, finally someone who has the proper interest for how to use a horn bow 8)
Sounds like an interesting bow that juniper recurve too. A good shot!

Good luck with the final tillering!

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This is it braced at 7 inches, drawn on tillering stick to 19 inches and hand drawn to 22 inches.
I can see that the kasan eye is flexing a little better at 22 and to my eyes the tiller looks good, i'm hoping that the kasan eye will flex a little more to become almost straight as in the pictures in Adam's book of fully drawn warbows. I seem to have eliminated the twisting out to 22 inch draw but cannot get the kasan eye angle to 'relax' with heat. I got to the point where I was worried that it might be getting too hot but still no loss of reflex here. Maybe i'll have to live with it as it is?
I will try and get it to full draw tomorrow...[/img]

Looking Good.

Nice to see someone else in the UK building composites.

dylan wrote:

Looking Good.

Nice to see someone else in the UK building composites.

Hi Dylan, where do you live? There aren't many of us here eh?!

Congratulations Mikekeswick, looks very good.

Cem

Hi Mike Keswick,

I live just south of Norwich, Norfolk. I presume from your internet handle your based futher north.

P.S. I've posted some of my creations on the Archer Interchange under the handle of Barney, but i suspect you've already seen them.

Hey Mike, thats looking fantastic! Congrats!

That bow looks good ;-)

It looks nice!!!!. I follow your posts at paleoplanet too. I am sure you will make great hornbows in the future.Seems you had much patience.Wish you luck man.Can't wait to see how you will manage with decorations.
Best regards

Thank you for all the kind comments guys.
I have run into a few problems now though. I had been drawing it to around 24 - 25 inches and the string would start to sit off to one side on the upper limb after maybe a dozen shots. So I tried to remove the twist ( it seemed to start in the sal). However un twisting the sal led to the tip also being moved - when the bow was strung again and drawn the stringtracking has become worse...
I have tried to un-twist the tip and get it back in line but to no avail...so now I seem to be stuck with either having the sal a little twisted and the tip straight or the sal straight with the tip pointing off somewhere where it shouldn't!
I am going to have another day of trying to sort it out today and will let you know how I get on.
Personally I think the kasan eye is still too reflexed? However as I mentioned earlier I can't seem to reduce the reflex there - even when the area is very hot?

Forget that last post - I managed to fix the problem. When I looked with a more critical eye the twist was actually in the kasan eye. 10 mins of heating a bit of pressure and problem solved!

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The unbraced picture is right after un-stringing and around 50 shots. I think the amount of set is very good. I was expecting more![/img]

Oh if you click on the bottom picture it's a video of a few shots with it.

The bow looks great, congratulations. What is the draw weight? You could draw a little further even though it will stack. After more use, once the bow stabilizes, the string can be made slightly longer (to increase the power stroke).

Adam

Awesome 8)

The string follow is really impressive, even though it had such short drying time :shock: Amazing! Cant wait to hear how it does at the flight range :D

:shock: very attractive. congratulations.

Adam the draw weight is 75lbs @ 28. I have been looking at the photo and have come to the same conclusion and draw it a little further - but this is still very new to me and this bow scares me a little...
Kviljo I made some new arrows for it 11/32nd shafts barrelled to 1/4 , spines between 57 -59lb, weights between 333gn and 369gn. They all landed within 10yds of each other at around 300yds. Then I tried some of my other flight arrows which were all lighter and lower spines these all went further, once the spine got below 45lbs they started to flap about. These lighter arrows all went further, between 340 and 370yds One arrow in particular consistantly flew 30yds further than all the others, it's 50lbs spine and 303gn, barrelled like all the others but fletched with tern feathers that are ultra thin. The feathers must make more difference than I thought.
Uli - thanks a lot!

Whohooo :D This is great 8) And congratulations on some very good distances!

Were these 28" arrows? How many strands are you using for the string? Dacron B-50 right?

I'm quite surprised that the lower spined arrows went further. Perhaps the correlation is only to the weight? 333gn on 75# is 4,44grains/pound. If one can get the arrows to keep the sufficient spine, lighter arrows are better. - if the drag is kept really low. Down to 3grains pr. pound seems to be the normal good ratio - for wood bows at least.

Adam's graph at page 174 is quite interesting, showing the advantage of really light arrows. Anyway, as you know, when speed doubles the air drag goes up by the square, so air resistance seems to be quite important, and especially for the lighter arrows.

Another question is how well a not fully cured bow will cope with shooting very light arrows. It might not be too healthy for it?

One of the major effects is the diameter of the arrow. This can really affect the drag. Another is the position of the centre of balance. If it is slightly closer to the nock than the geometric centre of the arrow, the arrow can gain several extra yards.

Secondary causes are the smoothness of the shaft and the thickness of the feathers.

Nock shape may be a contributor too. Since the nock is going to create turbulence, you can try to minimise this, but there are practical limits. I wonder if some of the features of the Turkish nocks were designed to take this into account. We are often told that they gripped the string, but not told they were loose on it. When the bow was released, the string was free of the base of the nock when it hit the inside of the lips.

Very interesting discussion about flight arrows and impressive distance shots ;-)

It is clear that with higher velocities the air drag becomes very important. I never heard about using tern feathers but they seem to be a good choice.

What is the mass of your bow, Mike?

JJ

Mike I'm deeply impressed! Very well done! Great work on your second bow congrats again!

Try pigeon feather :wink: over 350 meter is a good distance 370 is very good on this weight! Your bow and the arrows must be very good! At summer in back wind may reach the 400 with a fine arrow. :wink:

JJ - i've just weighed it and it's 330 grammes. The core is made of cherry (lemonwood handle) and it is low density cherry at that. Maybe it will lose a few more grammes with time as it dries further.
Fusizoli - I can get lots of pigeon feathers! I will be making some more arrows and will use pigeon on them. My lighter arrows all have moose antler points which weigh only around 5 grains each. This must have an effect on the balance point compared to 20 grain brass points. I've also been thinking about using some offcuts from a spindle (euonymus europaeus)stave I have as spliced in points. Spindle is very hard and dense and I don't have any more moose!

My best arrow has a simple iron nail drilled into the tip. It allows you to make the tip of the arrow very slim. However, I do think it is better to use a heavy tip, to move the balance point of the arrow forward, while still keeping the max diameter behind the measured middle of the shaft. Both attributes help stability of the arrow, making it possible to use smaller fletchings.

I hope to try some thin rawhide/parchment fletchings this year. I'll be using a glove and/or siper for the bow hand, though...

Light tip arrows only working in backwind and havier in head or sidewind or in humid air.

I ve got pigeon feathers from racing birds and it is much better than wild birds have, so try to find a club or someone.....
That is the best I was working with