Primitive Archer
Main Discussion Area => Bows => Topic started by: radius on August 28, 2009, 01:08:17 pm
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THE OBJECTIVE: test the holmegaard design to determine what is the ideal ratio of bending limb:non-bending lever tip, to maximize cast and minimize set. Here is the beginning. Everyone please participate and post if you want to.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture001.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture002.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture003.jpg)
As you can see, all these boards are equal length, thickness, and width. They are all going to pull 50# @ 28". The only difference is the ratio i just mentioned. We will see how things go.
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cant wait to see how this test turns out. Might have to use the winning combination to make myself one. Good luck! :) -the psycho ;D
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its gonna be a good test
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Thank you... This I can appreciate. will be very helpful.
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well its a hell of a plane
but cannot participate,dont have wood to waste
only have a limited supply of decent bow wood,cant afford to experiment with it like that
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Alright Radius,
I found some 4/4 quartersawn white oak today, myself. I think your experimental design with the three bows will provide more testable evidence but I'll throw in what I can with this. I have two pieces; 66" and 55". I'll be working this evening to lay out some design. The longer board has a knot but it isn't deep and can be incorporated into the handle, so shouldn't affect things. I'll show you what I lay out later.
I'm going to try to come up with a goodnproper scientific hypothesis for the test. And I thought I'd never use scientific experimental design from high school. ;)
Here's my boards:
[attachment deleted by admin]
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Parnell, ur tiller tree is so low you must have to crouch to use it!
Last night i made the first adjustment, by reducing the tips of all three boards by 1". The only reason for this is that i found it easier to reduce a ratio using 18:12 rather than 18:13. So now, all the bows will be 64" long overall. The other specs will be the same: 50# draw @ 28", 1 15/16" width of bending limb.
the ratios are 2:3, 1:1, 3:2...
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I haven't tried a Holmgaard yet, so I'll enjoy following these builds. Radius, what is your wood, and the width and thickness please?
Keith
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beg your pardon.
SPECS
white oak, quarter sawn, 4/4. It is about 17/16 thick, reducing to 15/16 after both sides are cleaned up. Each stave is 1 15/16" wide and 64" long.
#1. 12" lever (including transition), 18" bending limb (including fades)
#2. 15" lever, 15" bending limb.
#3. 18" lever, 12" bending limb.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture009.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture013.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture012.jpg)
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well i am ging out on a limb here right now and i am going to say that
if you tiller them all out properly that the bottom one will be the best performer with the least set
only due to the fact it has a longerworking limb
so keep us posted and lets see how things shake out
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Hey, Scott
This is very cool! Excellent experiment. I can't wait to see how this turns out.
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I think that either the top one will break, or the others will be overbuilt if they all are made for the same poundage.
Longer levers decrease (tighten) the bend radius of the working limb, so the limb will have to be thinner to keep the stretching and compressing of the wood fibers within allowable limits. But a thinner limb bends more easily (stores less energy), so it must be made wider to compensate.
It looks like you are going to make them all the same width. If you can get 50# out of that long-levered bow without it breaking or becoming a limp noodle, then that means your oak will handle more stress than the other two designs will place on it, since they will have greater (less tight) bend radii. Unless they are made thicker in the working limb, you won't be working the wood fibers very hard (overbuilt), and if they ARE made thicker, they will be much higher poundage than the other bow.
In other words, I think that the width of the working limb should increase significantly as you make the levers longer, if you want to get meaningful results. You could still do this with your blanks as you have them now, but you might need to drop the target draw weight some.
I would start with the longest-levered one, and see what kind of poundage it will handle without taking excessive set, then make the others to that poundage, narrowing the limbs as necessary to achieve target draw weight with minimal set.
Whatever you decide to do, I'll be looking forward to the results.
-Robert
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Hey, Scott
This is very cool! Excellent experiment. I can't wait to see how this turns out.
me too!
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Robert! Sounds like you've thought this through more than i have!
As for increasing the width of the limbs as the lever gets longer, that is a good idea that i never thought of. Hm...
Now i'm confused.
I cut the limbs this way today.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture015.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture016.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture017.jpg)
I could still narrow the longer limbs, as you suggest. I cut into the belly enough to leave 5/8 " material to work with. Hm...
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I always wondered if the Real Holmgaard Bent slightly in the middle do to its shorter length. I found that the longer the limb the More slower and shock I got but that may be just my attempts to figure out what they had to use back in their time, short people I do believe they were, also I would think since their bows were shorter they would be a less weighty Bow ???
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Yeah, i dunno PK...the ones i'm making are essentially going to follow what Dennis LaVarenne has to say, namely:
the HOLMEGAARD bow has 5 sections:
1. handle section which doesn't bend
2. two bending limbs
3. two non-bending lever tips
I think i might follow Robert's advice. Make the longest levered bow first, and then narrow the limbs of the other two accordingly.
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Howdy,
Wow Robert, that is some clear thinking. I brought my oak indoors for a few days to get it out of the humidity, down here. I've got the 66 and 55" boards cut. 2" wide. I was reading TBB3 last night, my wife picked it up for me a few weeks ago for my b-day along with an antique draw knife and antique pipe. ;D No wonder she's still on my good side. But, I digress.
I was reading the bows of the world section discussing Holmies. They list dimensions for a 52 inch design tillered to 25". I read past into the Meare Heath section and it discussed bowyer height and bow length. Average height was shorter in the past. Myself, I'm 5'10" and draw 27". Average height thousands of years ago for Caucasian folks was what 5'6" or so? I'm thinking the 25" draw @ 52" length for a 5'6" man about corresponds with my 27" draw at 55" got me thinking of following this experimental design, 3 bows same length 55 inches and lever lengths as the independent variable. Let me know your thoughts as I haven't cut anything yet (letting wood de-humidify).
And Radius, the tiller tree is low but it's a good space saver. I use a folding portable campers seat that I set up when tillering there. It does the job! ;D
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:)
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some progress...i have the longest-levered stave ready to tiller.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture024.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture026.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture027.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture022.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture018.jpg)
Robert was right, i think, whoever he is...this one has 2" wide limbs...the next two i will make progressively narrower....
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(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture038.jpg)
This one is now drawing 40# at 17" with a 1" brace. The bending limb is 1/2" thick all over.
Today was quite a day on the gauntlet.
PROGRESS
I noticed that no matter how much i scraped the limbs thinner today, the draw weight didn't change. What changed--and this was very interesting--was the area of the bow where i could feel the spring energy. At first i could feel it uncomfortably too much in the handle. I thought the thing would break. So i scraped the inner limbs. Scale, tree, vise, scale, tree, vise. The draw weight at a given length changed very slowly, but gradually the bending-force moved away from being centralized in the handle and now it is spread throughout the inner limb.
So far the thing shows no real set. I have drawn it to 40# probably 1000 times already. Well, maybe 800. Oh my back.
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TIP MASS
The tips are actually pretty light. They are 5/8 wide or so, almost an inch thick, but solid white oak and really strong. Once the limbs are tillered out, i plan to carve the tips, leaving plenty of strength but adding character and losing more mass.
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so far so good
but the left limb looks stiffer
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If you make the limbs narrower on the other bows it's gonna be harder to compare them..
You will be changing to many parametres.
Wasn't the objective to find the ideal length of the lever?
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not length of lever by itself, but the ratio of bending limb to non-bending limb.
I think Robert has a point. The thinner the limb, the wider it has to be to store the same energy without taking too much set.
One thing my objective is NOT: and that is to ruin two staves while making the 3rd one great.
I'm not using the scientific method here. I don't have a pre-formed hypothesis of what the results will be (eg, the short-limbed bow will break, or anything like that). Instead i am just experimenting with the design. I took Robert's advice in 2 respects. One, I lowered the target draw weight to 40#. That's still legal hunting weight here. Two, i will probably make the longer limbs progressively narrower, or else they will end up being 1/8" thick!
It's possible that any of the three ratios/designs will work, provided the limbs are crafted accordingly. That's fine, too.
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HEAT TREAT....what's the consensus on heat-treating white oak?
Marc St. Louis reports that it rates as 'EXCELLENT' in terms of reponding to heat treatment...i guess this means it increases cast and doesn't break. I think i'll give it a go...i need a day off tillering, for the sake of my poor back.
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I'm looking to do some wood removal tonight. I haven't used white oak, yet, with heat treatment. Is there some sort of a list of woods that respond well with heat treatment and others that don't? Just curious.
That bow is comiing along nicely, makes me want to start to jump on mine.
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i really like the shape! These bows are damn cool. My roomie came in and said, "Wow, that thing looks fierce!" Being such a hard wood as oak, this weapon definitely doubles as a bludgeon, once the arrows run out...
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TBB 4 has a section on heat treating wood by Marc St Lois. There is a list there.
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thanks yeah, i just read it...he says he hasn't actually worked this way with white oak, but that from what others tell him it rates as excellent. I am going to do it.
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Well, I've made some progress. These are 55" long, 4" handle, all fades are 1" and as of now 2" wide for bending limb. The top two are identical; 12" levers: 12" limbs, then 10":14", and 8":16". Top two are same, I may make one lower poundage later for my nephew as a kids bow.
[attachment deleted by admin]
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cool, parnell...be really careful with that top one....looks like it has a knot in the center of the handle, and this is where the bending forces are first felt, before the bend moves as the wood thins.
YESTERDAY'S PROGRESS
Got this bow pulling 50# at 24" from the back. It took some set so i heat treated it using the heat gun and pine varnish a la Marc St Louis. Now it is dead straight and waiting for its next session. So far i found the pull is smooth, easy, and the recovery is fast. I pull it to full poundage and sometimes simply relax my back and shoulders, and the return on the limbs almost takes my arms off!
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture058.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture059.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture062.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture061.jpg)
You can see how much set there was, by comparing the back of the bow to the lines on the kitchen floor.
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50# @ 24"
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture057.jpg)
Here's a picture of uneven tiller caused by too much puffing and not enough passing. It was actually quite a bit worse but i fixed it a bit before i thought to take the picture.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture053-1.jpg)
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my main tool at this stage is a cabinet scraper. The oak is damn hard, and i find i have to sharpen the scraper fairly often. But a sharp scraper is a wonderful thing, so it is worth it!
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here's a quote about white oak that i think was assembled by tim baker.
OAKS: California black .57; southern red .59; northern red, sessil, pin, bur .63; scarlet .67; white .68; Whiteoak is about as close to unbreakable as wood can be. In my bend tests it breaks after hickory. Bows I’ve made of white oak took large sets without much excuse. On the other hand, I haven’t been able to break a bow made from this wood. One was steamed into 6” of reflex. When tillered it took 7” of set, standing at one inch of string follow at 55lb, and equaled the cast of any equal-follow bow. Of several whiteoak bows, from several different trees, the one that stayed straightest was fine-ringed, high-percentage early growth. Quite strange. One correspondent reported less set in his white oak bows, others report similar set. White oak is extremely strong in tension.
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Very cool experiment! I've been thinking of doing the same thing, if I just could find the time.
But. I think if you are going to compare these in a flight-shoot or in a chronograph, it will be very dependent on how light you can get the outer limbs. This is probably the most significant advantage of the design - extremely light outer limbs. They also need to bend just a little to get them as light as they need to be for them to make the bow fast.
I've made a few of this design and used them for flight shooting, and it seems like the ones with very long outer limbs are the slowest, because they need to be quite thick not to bend much. The one that has shot the longest (389 yards) is this one. You can see the proportion of outer limbs to the inner. I feel that this is quite optimal.
(http://i26.photobucket.com/albums/c137/Ken1931/IMG_3518.jpg)
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okay, having fully decided that my objective is to craft 3 good bows, not 2 shit bows and one cool one, i have gone with Robert's good advice and made the limbs wider as they get shorter; or rather, i have made them narrower as they got longer.
The first one is full width, 2". The second is 1 3/4, and the third, with the longest bending section of limb, is just over 1.5".
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture064.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture065.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture063.jpg)
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okay so i got the first one to full draw.
Here ya go:
You can see from the full draw pic that the string angle is very low. It even LOOKS greater than it really is, because i carved away a taper off the inside of the tip, about 3/8" to nothing over 5".
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture086.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture095.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture084.jpg)
This was awesome. After heat treating it, i had a few benefits.
1. The poundage went up from 50 @ 24 to 50 @ 21.
2. It smelled like sweet pine sap when i scraped it.
3. The varnish seemed to have saturated the porous earlywood on the belly, and made the wood seem denser.
I tried a few different ways of carving the levers to reduce the tips and add something unique. The first attempt, some runes, looked bad so i rasped them off. The next attempt, a spiral, worked perfectly, but when i attempted to carve leaves in between the lines of the spiral, they looked bad (read,i suck) so i rasped them off.
This is pretty much how they look now.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture087.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture088.jpg)
The spirals are on in such a way that when the bow is drawn to full, they all seem to point at the nock. It's simple, but i like it, and strangely enough, just by using the same 45 degree angle that the string nocks have, the parallel lines wind up being 2.5" away from each other, fitting in perfectly with the length of the transition from limb to lever. Just a happy chance. I'm not that good.
Can't wait to see how the other two play out.
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looks cool! How does it shoot?
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well, josh, i live in the middle of a city and have no car to get to anywhere safe to shoot...BUT! in my apartment, this bow can hit the target from 10 feet away very fast
:-\ :P
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Tiller looks extremely good to me. Very cool bow with so long levers and short bending limb.
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thanks man...and i got this thing out to OVER 50#...it's a good one
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absolutely fascinating project. can't wait for the progress on the other two. thanks for taking us on this journey.
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thanks, Marius...
I have the other two bows at the same stage of the work:
both have:
nocks
all transitions blended in
bending limb reduced to about 1/2 " thick
bellies tempered
so...now i just gotta wait a few days and get back to it...meantime i'd like to work on my son's yew longbow...but that one hurts my back!
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looking good scott,
keep up the good work.
jamie
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thanks jamie
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Got a question. Why do most homie builders not take material off the ends to drop mass? I figured it would be better to remove just enough material off the tips to where its still barely stiff.
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Too much, too fast. Had it braced and pulling to 18" heard the bad sound. Knew it was on it's way.
[attachment deleted by admin]
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too much too soon, you say?
sorry to see that...could you see any defects in it from before? was there a knot there???? Looks like it broke in the middle of a decent section of wood...
Here's a few pics of my first one, finished up ... i wet sanded it with tung oil to 600 grit, and then applied 3 coats of tru-oil.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture103.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture104.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture106.jpg)
I've got #2 and #3 underway as well...both have been reduced, heat-tempered, and partially tillered on the long string.
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Got a question. Why do most homie builders not take material off the ends to drop mass? I figured it would be better to remove just enough material off the tips to where its still barely stiff.
For me, bowmaking is as much about aesthetics as functionality. Don't matter to me if the arrow flies 180fps or 160. Either way, it's gonna hit.
What? You don't like it???/
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Nice!
The growth rings are running horizontal on your bow in the first pict right? The other narrow brown stuff going in different directions, what are those?
Are they present in all ring-poruse woods?
I don't see them in Birch, Maple, Hazel..diffuse-porouse woods.
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I was aiming for 50 lbs. and using a spring scale to monitor my tension. It was bending nice and even, not over weight, when I heard a tick.
Still have the other two. We'll see.
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Nice!
The growth rings are running horizontal on your bow in the first pict right? The other narrow brown stuff going in different directions, what are those?
Are they present in all ring-poruse woods?
I don't see them in Birch, Maple, Hazel..diffuse-porouse woods.
oak has what i think are called "medullary rays" (could be wrong) they run at right angles to the grain, i.e., radiate out from the pith. Again, i could be wrong.
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(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture108.jpg)
here's a pic of me holding it at full draw...
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Okay, so that one is done and on the display rack, but ...
#3 (shortest lever, narrowest limbs)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture027.jpg)
#2 (1:1 ratio, mid-width limbs)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture024.jpg)
Ive got #3 tillered down to about 40# at 26, and i think i'm going to have to leave it at 40#....i'll take it to 28", but i have decided that this wood needs to be wider than 1.5" to handle 50#, even with this longest-bending limb design. I had it pulling 40# @ 18", tried for 19", and heard a crack. I searched the back everywhere for signs of a crack and could not find one. Dubiously, i set it on the tree and pulled it to 18" a good 50 times. Then i saw the crack, next time i took it down. But, this being quarter sawn wood, i just scraped down past the crack, and it seemed all good. I tillered off the back, cleaning up some of the skip-planing a little better and reducing the thickness of the limbs. Got it pulling 40# @26", tried for 27", heard a little crack. I might even take this one down to 35#... Going to continue, tillering off the back again and then rounding the belly. It will be what it will be.
FUNNY how the bow with the shortest bending limb held up better than the one with the longest bending limb, and i guess the key is the width. We'll see how the middle one turns out.
The middle one, i tillered fast, using the rasp alot. I'm trying to get my time down, especially on these easy boards with no knots or weird wiggles. Once i got it to 20 or wherever it is, i heat treated it again.
Here's the simple plywood jig (hole cut with a holesaw used primarily for installing door handles, 2.125") and the homemade "varnish"
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture026.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture027.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture028.jpg)
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#2's full draw looks wicked! Man!
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Clever jig!!
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Hey, Radius, I hugely admire and respect the work and thought you have put into this project.
I eagerly await the final conclusions.
Respect dude....
When is the movie coming out and who will play the lead? ;D
Del
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Hey, Radius, I hugely admire and respect the work and thought you have put into this project.
I eagerly await the final conclusions.
Respect dude....
When is the movie coming out and who will play the lead? ;D
Del
Thanks Del! I'm closing in on it.
#2 is finished. I left some of the burn marks on the belly, and tillered off the back. The shape is not exactly perfect, but as Parnell will probably remind me, perfect isn't the goal. Great is the goal! And i think that i've achieved that. As for the movie, the casting couch is in the back if you wanna come to tryouts! >:D
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture046.jpg)
#3 is not completed yet...I've got it pulling to 28" but i heard the crack again. Same spot. I've got some CA in it, and i'm thinking of just backing it with silk and then giving it away to a friend's kid. It'll be maybe 35# when i'm done. I think that this is the least of the designs. With that much bending limb, might as well just bend the rest of it too, and go for a longbow.
#1 i love, its long levers are like weapons in themselves. #2 is also a great design, smooth draw, reaches 50# easily. I will work with these two designs again, keeping the width as i did here (if using white oak...sure would like to try some elm). I won't make the design like #3 again, though.
#1 is out on display at a local shop, the Fernwood Square Store in Victoria BC...but here's a pic of the other two spooning.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture042.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture043-1.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture044-1.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture045-1.jpg)
Now let's see some action, Parnell!
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I've been slacking on these since the first bust! Been finishing up a couple others - one for a birthday gift soon. I'll get back on it this weekend! Great looking pictures!
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i need to recant my judgement about the short-levered bow. Although with its narrow limbs it can't store as much potential energy, its 38# @ 26" shoots pretty damn fast and is a very easy draw! I've got it all shaped...today will sand and finish it.
Next project:
I bought another board of this material, scrounged a piece of 2x8 from a jobsite near here, and created a recurve form with a different curve at each end. Measured the staves at 66" (huge for a recurve, i think), 60", and 54"...we shall see...
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I was aiming for 50 lbs. and using a spring scale to monitor my tension. It was bending nice and even, not over weight, when I heard a tick.
Still have the other two. We'll see.
after you heard the tick, did you break the thing intentionally?
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No - just kept tillering along. I took off a little more wood after the tick and then exercise and wham! It was a very loud break! It actually woke my wife up on the otherside of the house! Ha! ;D
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some pics of #2 (1:1 ratio) all finished up
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture054.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture055.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture056.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard2/Picture057.jpg)
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full draw on the short levered bow (38# @ 26")
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture027.jpg)
here are #2 and #3 together. #2 was heat tempered later in the roughing out stage, it was much thinner. It retained the reflex better as you can see.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture109.jpg)
and here are some pics of #3 all finished up.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture111.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture112.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture113.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture116.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaard3/Picture118.jpg)
I really like this one actually. Me and my roomie were shooting it in my apartment: it is easy to draw , feels taut, and shoots FAST...i take it back, i will do this one again...maybe 1 5/8
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Have you seen the Maple bow on p 104 in tbb4. Pretty close to your nr 3. Something between a Holme/pyramid.
I think I´ll try that one but make it crazy wide and slightly more pyramid to midlimb.
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haven't seen that one, i don't have the book yet
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Radius, experimentation like this is what got us wood bow builders to where we are today. 8) Thanks for taking on this project. I would be curious to see the same experiment using staves instead of boards to see the differences in results if any.
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thanks Pat, although i expect your tongue was in your cheek a bit...
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No, I was serious. The comparison between board and stave in this situation would be interesting to see. Not saying that one is better than the other but what are the differences?
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i meant, tongue in cheek about "where we are today"
i think with staves, you'd have camber to consider, and maybe the limbs be a bit thicker at the crown...one day
i want to get some elm...and work with that...the lumberyard sells red elm ... he says "it's red but it looks grey" ... 6/4 plain sawn stuff... use this?
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With 6/4 plain sawn you might be able to get staves from those boards. Red elm is redder compared to other elm but not necessarily red. ;D Red elm is an excellent bow wood! ;)
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Ok...
So what's the bottom line?
What do you reckon the best lever to limb ratio is?
Del
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Ok...
So what's the bottom line?
What do you reckon the best lever to limb ratio is?
Del
the BEST ratio DEPENDS on what you want to achieve.
SHORTEST LIMB: I think that for a higher poundage bow, the 3:2 ratio is awesome (lever:limb), provided you have enough wood to get the width you need. Reducing the lever itself in mass should bring up arrow speed too. Good power, good for hunting or for defending the fort or what have you.
LONGEST LIMB: Great for a target bow. It's very light and responsive. This bow is only 38# at 26" but it shoots FAST!
1:1 RATIO: Works awesome. I shot it after shooting the 38# (it is 50# @ 28" and shows zero string follow, thanks to late-in-the-game heat tempering)...and whereas the 38# shot fast and very satisfyingly....i thought the 1:1 could go right through a tank. This ratio is probably good for either a high weight (go a little wider) or a target weight (thinner preferably to narrower).
TBOD was right: i changed the parameters too much to compare accurately. I was surprised to see that the 38# couldn't handle more weight, since it has more length of limb to bend. Glad it didn't break! It actually pulls to 28" (around 44#?) but it gives that tick sound sometimes which i don't like. I put CA in the tiny little crack and wrote 26" draw length on the bow...hope that's enough.
For quarter sawn white oak, at least, You need to make the limbs a little wider than you would for say, Osage. But you still get a great bow! Even the 38# could probably down a deer, the arrows fly so fast! I really like the holmegaard look and the easy draw, the fast release...
I've got some elm coming in...gonna make recurves and holmegaards out of that, to see which i like better...
Hopefully i can get Robert to chime in about this project, since his ONE post influenced me so much...
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Ok...
So what's the bottom line?
What do you reckon the best lever to limb ratio is?
Del
the BEST ratio DEPENDS on what you want to achieve.
SHORTEST LIMB: I think that for a higher poundage bow, the 3:2 ratio is awesome (lever:limb), provided you have enough wood to get the width you need. Reducing the lever itself in mass should bring up arrow speed too. Good power, good for hunting or for defending the fort or what have you.
LONGEST LIMB: Great for a target bow. It's very light and responsive. This bow is only 38# at 26" but it shoots FAST!
1:1 RATIO: Works awesome. I shot it after shooting the 38# (it is 50# @ 28" and shows zero string follow, thanks to late-in-the-game heat tempering)...and whereas the 38# shot fast and very satisfyingly....i thought the 1:1 could go right through a tank. This ratio is probably good for either a high weight (go a little wider) or a target weight (thinner preferably to narrower).
TBOD was right: i changed the parameters too much to compare accurately. I was surprised to see that the 38# couldn't handle more weight, since it has more length of limb to bend. Glad it didn't break! It actually pulls to 28" (around 44#?) but it gives that tick sound sometimes which i don't like. I put CA in the tiny little crack and wrote 26" draw length on the bow...hope that's enough.
For quarter sawn white oak, at least, You need to make the limbs a little wider than you would for say, Osage. But you still get a great bow! Even the 38# could probably down a deer, the arrows fly so fast! I really like the holmegaard look and the easy draw, the fast release...
I've got some elm coming in...gonna make recurves and holmegaards out of that, to see which i like better...
Hopefully i can get Robert to chime in about this project, since his ONE post influenced me so much...
Cheers...That's we get hooked on this game...so many variables to play with, and so many different 'right' answers.
Del
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Cool stuff!
It's almost like a chapter in the bibles this project.
The best thing about board bows is that you can make them really wide.
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All right, let's all be honest now! How many of you right now have a "holmie" on the bench or at least have a stave/board set aside to become a holmie?
Hehehe, I have an elm tree picked out and am waiting for the leaves to fall before I cut it.
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Interesting bunch of building. I still don't have a feel for Homies but you did well. It was interesting.
It would have taken me all year to complete an experiement like this. And one or more would have broke.
I still wonder why folks leave the tips so thick. I figured they would take off just enough material to keep em stiff.
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All right, let's all be honest now! How many of you right now have a "holmie" on the bench or at least have a stave/board set aside to become a holmie?
I do. I didn't care for the design much until Radius started this project, but now I love it.
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All right, let's all be honest now! How many of you right now have a "holmie" on the bench or at least have a stave/board set aside to become a holmie?
I do. I didn't care for the design much until Radius started this project, but now I love it.
awesome, Josh, let's see what you come up with!
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bigcountry, did you notice that i reduced the tips on the second two? that was for you, amigo!
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bigcountry, did you notice that i reduced the tips on the second two? that was for you, amigo!
could you have reduced them more or would you have lost poundage?
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wouldn't have lost poundage, no: the draw weight is in the bending portion of the limb, not the lever...but i am pretty content, man, the tip mass doesn't seem to get in the way, cuz these arrows (yes, in my apartment!) fly like rockets!
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I have watched this project and yes I have a stave that I have started I took in account for the shorter limbs and the ratios I want to make one around 66-68'' and want limbs to b around 2'' and lever 12''long not sure but cant wait i tried to make an oak one and upon tillering a crack from a MYSTERY knot...oh well I have about fifteen hickory staves I got to get lucky with one of them!!! AWESOME AWESOME AWESOME all I can say!!! THANKS for this building expirement!!!
CHEERS!!!
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are you a really tall guy, VB? 66 or 68 is pretty long for this style of bow, i think...
strength and honour is from Gladiator, right?
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Howdy Group,
It would be good to have some hard numbers on arrows speeds when compairing one bow to the next. And, I know we all can't afford, (or don't want) a chronograph. So, I found this link that shows you how to, fairly accurately, find your arrow speed. And, after you find the arrow speeds for three or four bows, then you can compair speeds using %'s. I hope this works for you. (Yes, to do this you'll have to go outside to shoot - not just in your apartment. ;))
Arrow Speed Without a Chronograph;
http://www.texasoutdoorsman.com/Staff-Articles/VaughnRader/arrow_speed.htm
BTW, thank you very much for doing and sharing this project. Experimentation really is the way to development / improvement.
Furthermore, I think, one could condence the results of this experiment, add some commentary on limb widths and heat treating (perhaps), and he could write a very interesting and informative article for PA magazine.
All the Best,
Canoe
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Howdy Group,
It would be good to have some hard numbers on arrows speeds when compairing one bow to the next. And, I know we all can't afford, (or don't want) a chronograph. So, I found this link that shows you how to, fairly accurately, find your arrow speed. And, after you find the arrow speeds for three or four bows, then you can compair speeds using %'s. I hope this works for you. (Yes, to do this you'll have to go outside to shoot - not just in your apartment. ;))
Arrow Speed Without a Chronograph;
http://www.texasoutdoorsman.com/Staff-Articles/VaughnRader/arrow_speed.htm
BTW, thank you very much for doing and sharing this project. Experimentation really is the way to development / improvement.
Furthermore, I think, one could condence the results of this experiment, add some commentary on limb widths and heat treating (perhaps), and he could write a very interesting and informative article for PA magazine.
All the Best,
Canoe
Well, thanks brother! Gee, i wonder if the good Editors would be interested in such an article? Who do i ask?
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RADIUS u do some amazing work!!! U have inspired me to run out hack down a tree in my neighbors yard just to make one for myself!!! Let me ask u did u start from a Oak stave that u split urself or did u buy the white oak from a lumber store? Either way fine just curious!! Hey man keep up the good work!!!
CHEERS!!! 8)
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board bow from the hardwood shop, dude
then i got another one to try steam bending some recurves in...
i'm disappointed, though: i ordered some elm and it came in, but it's 9 feet long...that's 3 feet plus of extra, and i'm no good at handle splicing...
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wouldn't have lost poundage, no: the draw weight is in the bending portion of the limb, not the lever...but i am pretty content, man, the tip mass doesn't seem to get in the way, cuz these arrows (yes, in my apartment!) fly like rockets!
Holy cow, I bet your neighbors are ready to catch an arrow from time to time.
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I hate to be the nerd in the bunch, but some of the math that Canoe referenced is wrong.
The speed of the arrow math works out well given gravity as a constant and you can figure out time by distance dropped etc...
However, when figuring out foot pounds the equation (arrow weight)/450*(arrow speed)^2 don't jive. That gives you foot ounces. You have to divide weight by 16 in addition to 450 (437.5 actually) to get foot pounds.
So the right function would be KE=(1/2)*[(arrow weight)/(437.5*16)]*(arrow speed)^2
Don't blame me, I'm an engineering student.
Edit: Me and my big mouth, forgot that KE=(1/2)mv^2. whoops :D
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??? give me a little while on that one.
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Sorry, lemme try and explain things a little more...
The site Canoe linked to has a decent way of finding arrow speed without a chrono. (There's a better way to do it but maybe I'll start a thread of it's own for that)
However, I also has a little function to find the kinetic energy of an arrow.
Their equation is (arrow weight)/450*(arrow speed)^2
That would give you twice the kinetic energy in ounce feet.
After a correction to units to get foot pounds which is much more relevant given it's one of the British units of energy (I sure ain't measuring arrow energy in BTUs) you get the corrected equation of:
(1/2)[(arrow weight)/(437.5*16)]*(arrow speed)^2
If you still don't get it, don't worry the average on my thermo test that we dealt with KE on was 53 (I got a 74) so most college students don't either.
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Howdy M.Hamster and all,
Yes! Please do put together a user friendly page with (perhaps) examples and charts showing / describing those Arrow Speed and Kinetic Energy formulas. If you put some energy into it, the page would be very helpful to alot of archers here on PA.
And, maybe they'll move it to the Archive Library section for easy reference.
Thanks for your interest,
Canoe
Sorry, this seems to have gotten somewhat off topic. But actually, I think it's applicable to this thread especially because we're compairing bows including; speed and energy, as well as smoothness of shot, accuracy, etc.
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Whew! You've have been busy! :o All holmegaards bookmarked for Sept Self BOM which is coming up next week 8)
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Hey Radius - I had the second blow on me last night. Had it tillering, pulling with a scale and not going over 45#. It was flexing 10" and broke with no warning! I'm wondering if the dimensions I had for the 55" length and 2" wide levers is fundamentally trouble. That 2" is too wide for a shorter limb length of say, 14 inches working? What do you think?
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Hey Parnell,
The first one i made in this group of three was the 2" wide limb, 12" from the start of the fades to the start of the taper down to the lever. Maybe ur gung ho? maybe the wood is too dry? Maybe there was a glitch in that g'damn board and you got two breakers. Doesn't matter. Keep trying. I broke one last night, 54" recurve. God, if i'm gonna stay home on a friday night, at least the bow shouldn't break!
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Saw the link for the recurve break, nuts! Looks a lot like the break I had last night, too. Mine was close to the handle. Oh well. Movin on...
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All right, let's all be honest now! How many of you right now have a "holmie" on the bench or at least have a stave/board set aside to become a holmie?
I do. I didn't care for the design much until Radius started this project, but now I love it.
awesome, Josh, let's see what you come up with!
Unfortunately, it didn't turn out to well. While tillering, I heart the dreaded "tick" sound. I looked all over but I couldn't find anything, so I decided to just move on. I tillered it out to 30# @ 26" and did some finishing on it, shot a few arrows and then I heard it again. That time when I looked it over I found the crack. It goes in about a 1/2" from the edge of the limb and its about an 1/8" deep. The limb is only about 3/8" thick to begin with. I can still brace it, and the tiller still looks good at brace height, but I know if I try to draw it at all, its gonna snap. I've got a pic of the crack, although you can barely see it.
(http://i879.photobucket.com/albums/ab359/J05H/0927090119.jpg)
I'm thinking I might try putting a hickory backing on it and re-tiller it. Until then I'll just set it aside. By the way, sorry about your recurve.
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oak is not bad, but i'm thinking 2" wide minimum to be on the safe side, and somehow you gotta keep the pressure away from the inner limbs...
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I've given up on the neighbor letting me harvest his 8" diameter elm tree since he seems to think it adds some shade to his front yard, so I dug out a bur oak (Quercus macrocarpa) stave that was curing in the garage. The stave is 83" overall, has 45 degrees twist (all in the upper 24 ", easy enough to take out with gentle heat), and has two knots on opposite sides about 66-68 inches from the base end. These knots have 1 1/2 to 1 5/8 usable wood between and they cause a small dogleg in the grain of the wood. Eleven growth rings per inch, 8 of those growth rings in the outer half inch.
My goal is a holmie for a 30 inch draw coming in around high 40's to low 50 # draw weight.
To determine bow length, I use the "double the draw length plus 10%" for the usual flatbows, but with a holmie there is less limb doing the bending, so I wonder what formula should I use for this sasquatch armed kid with the 30" draw?
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Cool stuff!
It's almost like a chapter in the bibles this project.
The best thing about board bows is that you can make them really wide.
aw gee
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Well done Radius getting this experiment together, thats a lot of information to learn and must have helped many bowyers, good work
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thanks dragonman>
you never know until you know. I'll play this game again, with staves of osage or hackberry or elm or whatever i can trade for this yew.
The bow with the 1:1 ratio turned out the best. after this i make some white oak recurve 1.75" wide based on how well the limbs on this bow performed.
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funny to see this post resurfaced...Whats up Radius???
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funny to see this post resurfaced...Whats up Radius???
Dude, i miss bowmaking. All my stuff's in storage. I am moving tomorrow, out of this city where i have lived for 18 years. Yesterday i split some yew, and don't have time to work on it.
So i'm going over my old threads and i saw i missed a comment that i wanted to respond to.
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i'm glad you did radius, i think i need to make a holmie now, man! amazing work.
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thanks!
what kinda wood you gonna use?
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RED OAK! what else?
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Here is the proud owner of this holmegaard with his bow.
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture103-1.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture104-1.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture105-1.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture108-1.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture109.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20holmegaards/Picture110.jpg)
He loves it! Took a few tries to teach him how to string it...
And how do you like the get-up?
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cool pix radius but my neck hurts now from having to look at them sideways, LOL. ;) -josh