Author Topic: building a bow.. advice welcomed (Read 12640 times)

animus_divinus · « **Reply #15 on:** January 31, 2011, 09:12:40 am »

ok.. heres what i have so far.. with no plans at all to go on, and just word descriptions and photos.. this is what i imagine to be a holmgaard that i designed in a 3D solid modeling program

http://farm6.static.flickr.com/5214/5404523922_5793be47e9_b.jpg
http://farm6.static.flickr.com/5059/5403943195_a03d8128b3_b.jpg

the inner limbs are 2 x 1/2 inches, the outter limbs start at 1x1 and taper to 1/2 x 1/2... the grip is 1 inch wide, 1 1/2 inches deep (i have large hands and felt making it a tad larger here would be more comfortable)... and the overall length is 72 inches...

any comments about this?.. does this seem to be a proper holmegaard bow or did i get something wrong?

Hank · « **Reply #16 on:** January 31, 2011, 03:13:24 pm »

Nice 3D rendering. The proportions look right but not for a Holmegaard. What is drawn out is a Mollegabet. They both date to the middle stone age but the non bending part of the Holmegaard starts wide and flat then gradually tapers to a thickened point at the tip. Both bows function under the same principle- Low string angle at full draw and the non bending part of the limb increases the amount of leverage applied to the arrow upon release.

You picked a tough first build imo but if you go slowly and stick with it you will have a fine shooting bow. Red oak should do ok but you may want to consider backing it with hickory just to be on the safe side. Best of luck with your project!

Hank

PS: Here's a link to a page that shows the original Holmegaard artifact: http://oldtiden.natmus.dk/udstillingen/jaegerstenalderen/jaegerstenalderens_buer_og_pile/verdens_aeldste_buer/language/u/

animus_divinus · « **Reply #17 on:** January 31, 2011, 11:34:47 pm »

i had a very simple formula for making that bow.. all proportions relate to other proportions of the bow... i also figured id extend the length of this bow and size of the grip to better fit myself, as im a lot taller than any caveman was, whats a 72" bow to one of us is probably more like a 60"-66" bow to them, so i made it proportionally to my size

the link you sent me is to a top view image.. there is a slight step between the inner and outter limbs, but its a lot more subtle... i would LOVE to see a side view profile of this

my wood options are white oak, red oak, cherry, and hard maple locally, i can only get the proper hickory, osage, yew, or elm bows if i shop online.. and i have been thinking of elm to be more accurate to what these stone age bows were.

animus_divinus · « **Reply #18 on:** January 31, 2011, 11:40:24 pm »

actually.. i just found a mollegabet bow with listed proportions, i hit the nail on the head with the formula i used and didnt even realize it.. thats just cool.. im going to save these dimensions since theyre spot on to exactly what i would need if i make a mollegabet.. now i just need to make one of an actual holmegaard and make a decision

animus_divinus · « **Reply #19 on:** February 03, 2011, 02:48:34 am »

ok.. heres my criteria.. id like something in the pyramid bow design if possible.. backed or unbacked if possible.. roughly 65# at about 32" draw

materials i can get in quartersawn lumber with grains running end to end are red oak, white oak, hard maple, and ash...

the design ive come up with currently have .75" thick limbs that begin at 2" and taper to a point and i want roughly a 72" bow

my questions is... of the materials i mentioned, which would be best to use?.. of the materials mentioned are the limb thickness and width going to be able to deliver that kind of force?... if so, am i going to have trouble with grains lifting from the back of the bow needing me to back it?

if this bow needs backing to prevent grains lifting, would rawhide, or at the very least, linen be sufficient to prevent this and give me a good strong bow?

Pappy · « **Reply #20 on:** February 03, 2011, 06:59:26 am »

Any of the above should work for that,3/4 limb thickness should be more than enough, I usually start about 5/8 and Rawhide should be fine,I use it a lot,deer or goat is better than cow just because it is thinner/lighter and still very strong.

You just need to get a piece of wood and go for it,a plan is good but nothing like doing it.

If you try and over think it ,it will drive you nuts.
You must have an engineering back ground.

Pappy

Grunt · « **Reply #21 on:** February 03, 2011, 08:46:38 am »

Start a bow building journal and record your dimensions, wood type, techniques, mistakes,successes, etc. Seven ounce linen canvas makes a good backing for oak board bows. Quartersawn wood is hard to read because all four surfaces need to be straight lines. Have fun, learn new stuff!!!

animus_divinus · « **Reply #22 on:** February 03, 2011, 09:19:05 am »

ive considered rawhide on a holmegaard style pyramid bow, but i might hold off on a pyramid bow until i can get something like a wych elm sapling and some stone tools to really give it a try the old fashioned way

so.. maybe a european style flatbow thatll give me a little more freedom to be a little more creative

i will write down findings in some sort of a document on my computer, as well as save the 3D cad files i create and use to print templates for the rough cutting of the core wood

i believe its 3 rivers archery that sells 72" long hickory boards for making bows... question i have is whats better, a hickory board bow, or a hardwood core of maple/oak with a hickory backing?... either way i could use linen, maybe even dyed linen for decoration and aesthetics

HoBow · « **Reply #23 on:** February 03, 2011, 09:52:53 am »

I'm guessing no one will ever accuse you of jumping in without a plan. I'm more of a jump both both in and pray I can swim type

go to home depot/lowes/Menards and get a few red oak 1 by 2s and go to Jawges website. Half this website probably got started that way. A plan is good to have, but the wood may have a different one...good luck and have fun with it.

Pappy · « **Reply #24 on:** February 03, 2011, 10:36:59 am »

Pappy

Parnell · « **Reply #25 on:** February 03, 2011, 10:56:39 am »

Welcome to PA, AD!
A hickory board always gets my vote for beginning. I've broken MANY more oak attempts. But that's just me.
Hickory performs very well is you toast the belly of the bow. If the grain is running straight on the back, it takes an awful lot to break. The toasting of the belly at ground tiller compresses the cells so that it doesn't take too much follow. I've had lots of succesful hickory bows that are absolutely hunting quality. You've got a 32" draw, I saw? I had a young guy make his first bow - hickory - with a very long draw - almost 34". He's almost 7' tall. American flatbow, toasted belly, almost 60# at 33". All the woods listed will hold but hickory is a very safe and durable bet.

Just my two cents, good luck!

animus_divinus · « **Reply #26 on:** February 03, 2011, 02:41:57 pm »

well, the process of selecting wood is a little easier for me, i have a local lumberyard that had ash, white oak, red oak, hard maple, and a couple other hardwoods available in quartersawn boards with perfectly straight grains, so i really have quite an available, inexpensive selection here.. unfortunately i checked, and they do not have any suitable pieces of hickory.. so should i actually use hickory i will have to get it online, which means youd have to stack the cost of shipping on that too

i know other hardwoods are more likely to have grains lift, and are more prone to splitting because the wood itself cannot take the stretch that hickory, and other premium bow woods can, but some major questions i had are, is a hickory backed bow just as good, better, or worse than a straight-hickory bow?... also, how effective is rawhide or linen in preventing the grains from lifting on the back of a more common hardwood?...

also, should i use a more common hardwood like maple, red oak, or ash, are there any backings besides synthetics or other pieces of wood that i could use to maybe increase performance instead of just greater durability?

Parnell · « **Reply #27 on:** February 03, 2011, 03:28:34 pm »

The ones you've listed can all make a very fine bow. I'd just pick one and get on with the process. You can read about tillering until you're blue in the face but doing it is another thing. Hard maple makes a very light and quick bow. I think I'd choose that, if it were me. Haven't used ash but would like to. Oak is always a good bet. Look for more red colored red oak and of course look for the best grain. I'd choose the board that had the straightest grain on all sides of the board and go with it. Linen backing is straight forward and works well. I've applied it using TB2 and had good results. Rawhide is great, haven't done one yet but seen many.
The only "natural" backing that improves performance is sinew, but the bow needs to be a shorter length to take advantage of the properties of the material. You'd want to match sinew with a bow wood that has good elastic properties. Hope I'm not being redundant.

Cheers.

animus_divinus · « **Reply #28 on:** February 03, 2011, 03:34:06 pm »

well im curious as to what properties sinew would work better at?.. obviously since im not a very short person, a shorter bow may not get me the draw i need in a longbow shape, and for the sake of simplicity i dont want to be steaming any wood right now or going for a laminate

RyanY · « **Reply #29 on:** February 03, 2011, 04:12:01 pm »

I've had good experiences with hard maple and if designed correctly you should have no worry about breakage if all else is good. The bows I've made of maple were 66-68" with an 8" handle, 2" to mid limb and a straight taper to 3/8" nocks. They were probably a little over built but all shot great and were really easy to tiller.

Primitive Archer