Andaman-Holmgaard Horn Composite Thoughts n Q's

[blackhawk]

As the title states ive been wanting to try this for awhile now.....so yesterday i started thinking,plotting,planning,and drawing out a scale model of what im after. Now i havent attempted a horn bow yet so this is all new territory to me...and im usually too stubborn n cocky to ask for advice,but i think its wise i do this time.

The only person i know that has tried this was Tim Baker....hopefully Steve(badger) will chime in and give his thoughts on this one as he tested it with Tim. I dont know if he tried another one with wider working limbs than the first one(which was only 3/4"),and made the improvements on a second or third??  Steve do you remember the lentgh of the bow?

So heres my idea and drawing to scale so far(hope ya'll can read my chicken scratch)....its 51"ttt for a 50" ntn bow. 1.5" wide working limbs,and ill prob narrow it some at the handle area to around 1 1/8" or so. It will bend full compass thru the handle...the horn and sinew will feather into the fades of the levers,and then wrapped there for reinforcement. I am wanting to pull in at least 15" of reflex. Not sure if ill deflex the handle area,but i dont think i am. I have plenty of horn to play with and i can use only one strip of horn for the belly. Theres only 20" of working limbs,or should i say "limb". Im wanting to take it to 28" draw. Its a 60/40 lever to working limb ratio.

So heres my choices im at right now...i have HHB,osage,yew available for a wood core...some say osage is too heavy for horn composites,but this isnt a normal composite and all the weight will be down low and barely nothin out past the working limbs. And in my experience osage is the best wood for lever bows due to its toughness at super narraw scary   yew is lighter,but the levers will ding more easily as theyll be exposed....and im not to sure of HHB taking that much shear stress as its only 10" of working limb per limb. Now i know ya'll are gonna tell me maple..right? Well,i aint got none. I suppose i could go cut some tho. But this design doesnt look like it will be as stressed as a turkish horn bow so maybe the woods i listed wood work if done right. And wood i have to make sure i have matching grooves for the horn n core with this design? Adam states its not so important in lesser stressed designs to have matching grooves,but it increases the chances of longer lasting durablility in doing so.


So yes...i do have Adams book. Anyways heres the first scaled drawing


 

[Buckeye Guy]

Go for it !!
Looks like a blackhawk bow to me !!

Have fun !
Guy

[Gus]

Blackhawk,

I've also read Adam's book a time or two.
What about a Mulberry core?
I have some mulberry aging with just such a bow in mind.

Look forward to seeing this bow come together.

-gus

[ken75]

i know nothing about horn sinew , but build it first using wood glued in reflex to scale . and then decide if horn sinew could improve on what you have . upside to this way is you have two bows to play with , one while you wait for glue to dry

[tattoo dave]

Crazy cool idea!! I hope it works, and can't wait to see some pics. A build a long would be awesome...hint, hint!!!

Tattoo Dave

[mikekeswick]

Blackhawk - i'm making one of these right now...I think this design has GREAT potential.
First osage will work but you will find that because there is such a difference between early/latewood then you will likely get depressions in the early wood. Trust me on this one. Of course the best way to overcome this if you are using osage is to use it 1/4 sawn. However it becomes less laterally stable this way.
Why not use some kiln dried maple? It works fine and will (obviously!) already be in board form. Flawless straight lines = essential, no matter what anyone tells you.
Maple is the key choice due to it's liking of glue and at the end of the day the master Turkish bowyers knew their stuff. Sure experiment away but they had already done all the experimenting and therefore KNEW (not guessed!) what to use. I managed to get away with using cherry for my core before I figured out everything I needed know to succesfully bend kiln dried maple.
Mulberry was used for the spliced in kasan/tips due to it being able to be bent like butter with steam. It's not really suitable for cores.
You definately want a diffuse porous wood for the core because these woods are more like homogenous materials compared to ring porous woods. I used elm on my very first core and it sheared along the earlywood..... I think osage works (but only just) due to it's bad ass toughness!
Matching grooves are not essential but if you follow Adam's technique of the scraper with the projecting/moveable foot then it isn't difficult. DO NOT touch the mating surfaces of the horn and core with bare hands - get yourself some cotton glooves.
Personally I think it's a better idea to have a rigid handle and fades. You need to really stress the horn or else it will be slow/soggy shooting. Don't worry about the horn/sinew not being able to take the bending
http://i492.photobucket.com/albums/rr283/mikekeswick/074-1.jpg
Most Turkish bows are in the region of 44 -48 inch long and they have rigid kasans, the sal being less than a foot.
Good luck.

[blackhawk]

Ill first state here that my computer is still trying to process this all,so forgive me of my "thinking out loud here"....

Thanks for being my personal cheerleader guy 

Dont have any mulberry gus,but sounds like not so great for a core...and white mulberry was used..not sure what type you have? And what exact type of horn bow are you wanting to make?

Ken..ive already built plenty of lever bows self and grass backed with 0-3" of setback after all is said and done...and it seems like this is the best and most i can come up with as far as results there....so the horn n sinew wood allow me to put in a HUGE amount of reflex and keep it...if i was to induce that much in a wood backed lam or selfbow it wood not take the strain....im already straining them as far as they can go...horn n sinew are the next progression for me with them,and it seems only logical to do so,and i also think it has great potential

Dave...not sure about a build along as ive never done this before and wood be totally winging it...but maybe its a good idea to post my progress as i go for advice n tips from folks


Mike....(ill take a big deep breath before i start).....wood you care to share your specs of yours and the whys? If not here maybe send a pm if ya dont want all to know your secret powerhouse in the works...but if we collaborate together then i beleive much can be solved to figure out the best way for this design. I know maple is great as a core but its only so so for in levers,especially in a 60/40 ratio design with edge grain kiln wood(not good at all for lateral stability and wood need more mass to keep em stable being so long n narrow attached to highly reflexed limbs)...sooo what im looking for a wood that wood be a compromise between core and lever....im thinking a clean HHB stave might be the ticket...its good core wood,and the levers wood be in stave form,meaning the best for stability and rigidity,and you could go less mass as possible this way instead of any edge grain wood.......as far as the bendy handle i wood be able to retain a better string angle as levers arent gonna retain as well as a siyah does,plus you wood be able to really reflex it hard thru the handle and wood be stressing the horn plenty with only 10" of horn per limb.......the otheside to that is if i did put a stiff handle in i could do as Tim intended and did with the andaman holmgaard bows and make a long stiff center section,but still have the same ratio of working limbs as the one i drew up...thoughts there?? String angle wood be low,but limbs wood be stressed the same,and the mass in the working limb and levers wood be the same,and might have even greater cast this way as its a longer bow??  Ok my brain is hurting....i need to stop n take a breath............

[Badger]

  Chris, I am trying to recall the bow. Tim and I tested so many none of them really stand out anymore. The only one similar that I can recall was like 76" long. For a bow like this I would consider hackberry as a great core wood. Hackberry can be shaped with steam more than any other wood on the planet.  I have alwasy felt if the Asians had known about hackberry they would have been using it. At 51" long your design looks very feasable. I would consider a stiff short handle. With the short working limbs and long levers you may not need more than about 6" reflex to get those limbs working. I would think that osage or locust would be ideal for the levers. Looking forward to seeing this one. After seeing your skinny tip locust bows I don't put anything past you at this point.

[PEARL DRUMS]

Ill donate the hackberry sliver if you need some extra seasoned stuff.

[blackhawk]

I wood think hackberry wood be a poor candidate as a core because its ring porous,and wood be poor for gluing.....but i wont dispute its bending properties

Maybe there wood be a way to splice in osage levers in a maple core? Actually yes i do believe i could....just splice it out past the fades to the levers....but that wood account for more weight in the limbs due to being a lil wide at the base of the levers for the splice with reinforced sinew...?? Hmmmm??

[mikekeswick]

Blackhawk - i'll post some pictures tomorrow.
As Badger suggested locust might well be a great wood for the levers. Very stiff for it dimensional volume....
I only mentioned edge grain if you were stuck on using osage (early/late wood problems with flat ringed)for the core.
If you use maple/hornbeam then flat grained is best. I think hornbeam is too dense really for a core but would work i'm sure. Maple is the best all round bet IMHO because it glues excellently, steam bends too any shape needed,diffuse porous and works easily/consistantly.
Be careful of too much reflex in the working limbs as the layers are trying to seperate during bracing...better to reflex the handle (if stiff) and splice in reflexed tip sections  with only a little reflex in the working limbs. The tip splice only needs to be a 1 inch wide v-splice also no need to reinforce it there so weight can easily be kept low.

[Buckeye Guy]

W splice front to back inside the fade ?!!

[blackhawk]

Dang Mike..ya beat me to the punch ..ive been wanting to try this for a year now...looks like your the guinea pig tho  ...n maybe ill wait till yours is done to start mine so i know what to improve upon  ........cant wait to see pics of your creation,and hopefully maybe some stats with it,like widths,lengths,and your limb to lever ratio??........i do have a clean Hophornbeam stave that might work,it has a 1/4" knot dead center of the handle,but if i make it stiff handled then it wood be fine cus the rest of it is clean as a polished whistle. Ill put some pics up of it tonight....it has a wee lil bit of twist,but i could easily heat shape and correct it after i tillered the core. Im trying to stay away from too many splice jobys...but if its not acceptable ill look for a plain sawn perfecto maple,whether it be a tree i cut or a board. I do have locust to sacrifice for levers,it does seem like a good candidate for the levers......you realize how hard those puppies are gonna slam home?   


Keep waving those pom-poms guy  

[Badger]

......"you realize how hard those puppies are gonna slam home?  "

Chris, surprisingly on a very fast well designed bow the tips don't slam home. The  leverage is such that the arrow effectively slows them down to a near stop just before leaving the string. When they slam home you loose tons of energy. That why the light tips are so effective, partly because they accelerate faster but largely because they carry less momentum and are more easily slowed by the arrow.

[blackhawk]

......"you realize how hard those puppies are gonna slam home?  "

Chris, surprisingly on a very fast well designed bow the tips don't slam home. The  leverage is such that the arrow effectively slows them down to a near stop just before leaving the string. When they slam home you loose tons of energy. That why the light tips are so effective, partly because they accelerate faster but largely because they carry less momentum and are more easily slowed by the arrow.

Then that explains why my lever tipped bows are so quiet,and ZERO handshock...and now when i shoot an "average" built bow i think its shocky.....

So let me rephrase...."you realize how hard those ARROWS are gonna slam home"....