We left off using a string a little longer than the bow, bending it about 6" on the tree.
Today, I continued on, one inch at a time, fixing minor flats and stiff areas as I went, exercising it 40 times after each correction before drawing to the next inch mark.
Once I reached 8" of limb travel, I went to a shorter string, one which would bring the bow to a low brace height of about 4".
If I try too hard to get it to match the other limb, I may thin it too much and cause a hinge there. So I'm trying to judge them independantly, while keeping them syncronized.
The only part still untouched is the bamboo nodes and rind. I'll get them cleaned up tomorrow.
It's got a trapezoid-shaped cross section for most of the limb, becomming more oval-shaped near the tips and dips(just outside the handle area).
This thing is kind of impressing me because it's strong for how petite it is. Very good early string weight... should build weight evenly as it's drawn. But it hardly looks like there's any wood left! lol It's physical weight is now 15.5 oz.
I then tweaked the handle a bit because it felt just a little too big…. Actually, it felt just about right, but will be a hair too big once the leather is applied, so I scraped and sanded it until it felt just about right….
I'd go out and start shooting it if it wasn't raining out there. That raw wood would soak up the rain pretty directly me thinks :(
I'm betting she's gonna be smooth but quick shooter.
I'm more and more convinced all the time that limb timing, relative to the archer's shooting style, is the ticket to the best shooting bows right out of the gate... NOT tillering to generic, predetermined 'tiller measurements', and then messing around with brace heights and nock point heights trying to mask built in idioms. I don't have time for that nonsense.
Bows exist purely to shoot arrows well. Why build them to do otherwise? If I had built this short little thing to reveal say a 1/4" positive tiller as many suggest, I'd still be messing around trying to get it to shoot right... and draw balanced... and maybe convince myself it's good enough when it could be better... maybe fight it even more when I start shooting broadheads from it. Right now the tiller is dead-nuts even... and I'll bet this thing shoots broadheads exactly like it shoots field points. Regardless of the varying other aspects of bow design and performance, how the arrow is treated by the bow should be one of, if not THE main focus from the very beginning, IMO.
Tonight I simply strung the bow, served the string, set a nock point exactly where I tillered/timed the bow for from the very beginning... and bingo... arrow flight was excellent. Even though that was 'the plan', I was REALLY impressed with how that first arrow flew. It was laser straight. I just stood there in awe, lookin' at the bow, big grin on my mug in the cool damp evening with the spring peepers singing in the background. Very cool.
I kept reaching out farther and farther until I was pickin' off leaves, or hitting right close to em, at over 45 yards. I was equally impressed with THAT because the 3 dozen arrows or so I shot tonight were more than I've shot in the last year and a half. Who says to shoot stickbows you have to shoot a lot? lol I can't tell ya how good it felt to be shooting again too :)
Oh yeah, how ya like that trophy tree kill shot? Hickory arrows are so tough, you don't have to wait for them trees to become mushy old stumps :)
She's a Jewel.
Same thing with the differences between three under and split finger releases. They affect limb timing/relative limb strength and so, can be accounted for during construction.
Yes, what I did was find the center of the blank, then measure up 1 1/4" to locate the top of the handle/shelf, and then down from the center 2 3/4" to find the bottom of the handle. This puts the handle center 3/4" below the bow center... and my string hand fulcrum point (the hook on the string) above bow center by 1" or so. Meaning the true bow center is balanced well between the fulcrum points of both hands.
Actually, all the above measuring was done prior to glue-up so that afterwards, the deflex will be centered in the handle, not the bow, and both tips start the same distance in front of the handle. Remember how your tri-lam had more 'riser' showing above the handle than below it? I'm guessing that's because you glued everything up symmetrical and then shifted the handle down to, in effect, shorten the bottom limb?
I'm just trying to think 3 steps ahead is all.
Plan the work... work the plan :)
If I want a 66" o.a.l. bow, I cut all pieces 66" Then find the center... and from there layout the handle in such a place that the bow will balance on my middle finger. The exact handle position varies depending on bow length... but for a 66" bow, I would measure up 1 1/8" for the top of the handle, and down 2 7/8" for the bottom of the handle... which makes the bottom limb 1 3/4" shorter than the top.
On English longbows of say 72" long... there would be a full 2" difference in the limbs.... find the center... from there measure up 1" to the top of the handle and down 3" to the handle bottom. It will then balance nicely in the hand like the others.
Clear as mud?
So you find the center of a 66 inch bow, which would be 33 inches where I went to school. And from there you lay out the handle from "such a place" where the bow balance's on your finger. Which that balance point might not be the exact center of the 33 inches we measured on a 66 inch bow, because of the inherent makeup of the wood density in each limb.
So how do you figure the bottom limb is 1.5 inches shorter according to your theory, unless the bow balance's below the actual 33 inch center point by 1 1/2 inches?
I see what you are saying about the ELB. But you only measured up 1 inch from center and down 3 inches for a 4 inch handle, so yes that moves the balance point lower on the handle/center of the bow tip to tip. But you said earlier that even with the layout of your handle, the flare to tip measurement for the bottom limb is 1 1/2 shorter. How the heck can that be? We need a One On One Bownanza soon, I need to see this hands on son:)
I made a BBO bow for Pearl Drums on Trad Gang. Took three tries to get him a bow, the first two ended up with a bottom limb with a great bend and a flatter top limb that looked like crap.. I make my bows with equal length limbs, that makes a "big difference" using your theory of the pull rope coming straight down the line. On the third bow I was having the same problems with the bottom limb acting stiff. Because with both limbs being the same length and pulling for split finger which applies more pressure to the top limb, naturally the top limb to the right would come down the tree more than the left limb/bottom limb, making the bottom limb appear to be stiffer. I decided to cut 1 1/2 off the bottom limb to agree with how you make your bows and the bow came out fine. So with bows that have a longer top limb and pulling for split finger, that means the top limb tip has to travel further in relation to the bottom limb, thus your theory works well.
Clear as mud now? LOL
Let me see if I understand.
You find the center of the bow and then you measure 1 1/8" above the center and 2 7/8" below the center. Because you know that somewhere in that 2 7/8" below center will balance on your middle finger.
So how did you come up with 1 1/8"?
I just made some quick measurements and found that its 1 1/8" from the top of my hand to half way between the first and second knuckle.
And its also 2 7/8" or very very close to it from the bottom of my hand to that same point between the first and second knuckle.
That'll put the physical center of Jeff's bow pretty close to center of the hand.
But that's just a guess on my part.
Mmmm, nah, not because of the density... and it's not as simple as straight 'lineal' math, Phil :) It goes more by geometry, mass placement, pivot point, etc.
I'm trying to make this as simple as I can... but unfortunately it's simply not a simple thing to spell out :) This is going to get kind of 'deep', but here it is... for anyone willing to try to follow me...
I prefer the bottom limb shorter so the bow will balance in my hand(as close to the center of my middle finger as possible). This point of balance I seek, for MY hand, which measures from the top, as viewed while holding a bow, down to the center of my middle finger, about 1 1/2". So I strive to make my bow balance 1 1/2" below shelf/top of handle. Close is good, but I strive for perfection, and then take what I get. We're talking wooden bows here mostly, some with big knots, holes, snakey grain, internal gremlins... they're not always uniform inside and out. But I apply this to my glass/wood laminated bows as well.
So far so good? Ok, hang on, it's about to get a little more 'involved' :)
With the above said, please understand that THAT 1 1/2"(my physical hand/finger measurement) does NOT directly correspond to the single example above I used of a bow whose bottom limb I would shorten by 1 1/2". I'll explain in more detail in a minute...
A symmetrically-designed bow with EQUAL length limbs, with the handle center and bow center at the same place, will be forever trying to fall out of the bow hand, tipping down toward the bottom limb. Whether held at my side belly up or belly down, braced or unbraced, while canted to various degrees, or swinging/maneuvering for a shot, I want my bow balanced so it isn't always trying to tip out of my hand. I want it to point and move as effortlessly as my index finger. I'm particular that way... cuz I can be I guess. It's really no more difficult to make a bow 'this way'. And in fact, in some ways, it's easier.
Now granted, a bow balanced in the hand as such isn't a necessity, it's just ONE way to design it and build it, but it's my(our) preference... many others do it too.
Now, if you DO make a bow with the bottom limb shorter for balance, HOW MUCH shorter you must make it in order to maintain the same point of balance is related to its overall length(and handle area mass). You might want to read that again... I know I did several times to make sure I said it right :)
In effect, the longer the bow is(and perhaps to a lesser extent, the more mass in the handle area), the MORE you have to offset handle center from bow center to achieve the balance. The shorter the bow is(and the less mass in the handle area), the LESS you have to offset 'those centers' to maintain the same point of balance... on the middle finger in my case. I'm talking mere fractions here.
It's basic physics... Think balance beam.
Example... The more you chop off the bottom limb, the lighter and shorter that side of the balance beam becomes, BUT... BIG important BUT here... the new balance point doesn't simply move to the new geographical center(center of overall length) of the bow because when we chopped(designed) say... 1 1/2" off the bottom limb, the handle center moved half that distance, or 3/4" toward the bottom limb with respect to the NEW bow center... and 'some' mass weight shifted to that side with it... the important thing IS, some mass DID move, so it wasn't quite an equal trade. And this slight 'inequality' is what moves the balance point of the now altered 'balance beam', slightly in the same direction as the handle shift(with regard to new bow center)... putting the balance point under the center of my middle finger... assuming I 'chopped off' (designed-in) the correct amount in relation to the bow's overall length(and handle area mass). If all goes according to plan, and the bow's not a complete freak full of surprises and differences between the two limbs, the balance point will actually be somewhere between handle center and bow center. And, since I will pull with my string hand from slightly ABOVE bow center... this is why Roy found it easier to tiller/syncronize a bow of this design/construction method... We PUSH from slightly below bow center, and PULL from slightly above it.
Conversely, symmetrical bow design, by design, may be more symmetrical to LOOK at, but is less symmetrical in 'function' :)
Aye, Roy? I know you've now got a quick taste of it.
A little bit goes a long way when it comes to offsetting those centers. 1/8" one way or the other can make a huge difference in how the bow 'holds' or balances. I know this to be evident because, well, I've seen it countless times, but also because the centers (handle center and bow center) of my shortest bows are seperated by 3/4" while the centers of my longest are seperated by 1". A difference of only 1/4".
Roy said, "So how do you figure the bottom limb is 1.5 inches shorter according to your theory, unless the bow balance's below the actual 33 inch center point by 1 1/2 inches?"
Actually, I thought I said I would offset the centers of a 66" bow by 7/8"... up 1 1/8" and down 2 7/8" ...which makes the bottom limb 1 3/4" shorter, not 1 1/2". But, even so, it should still balance, hopefully, at my middle finger, which is 1 1/2" below the SHELF, not bow center.
"I see what you are saying about the ELB. But you only measured up 1 inch from center and down 3 inches for a 4 inch handle, so yes that moves the balance point lower on the handle/center of the bow tip to tip. But you said earlier that even with the layout of your handle, the flare to tip measurement for the bottom limb is 1 1/2 shorter. How the heck can that be? We need a One On One Bownanza soon, I need to see this hands on son:)"
The 1 1/2" shorter thing only pertains to bows of lengths in the 60" neighborhood, give or take a few inches either way. Bows in the 70" neighborhood are usually 2" shorter in the bottom limb... created by 1" up, and 3" down from bow center. The balance point though that I'm shooting for is still the center of my middle finger... 1 1/2" below the top of the handle.
Pretty crazy stuff, aye?
Dizzy yet? lol
Actually, once you apply it in a practical sense a few times, it quickly becomes quite simple to understand and deal with. In fact, this is the most I've thought about it for a long time... nowadays, I just kinda 'do it'. In reality, there's only a couple things and numbers I have to remember.
Well, anybody make it through that quagmire?
This is intense stuff, I know... especially for here... nothing against YOU guys. Heck, I haven't even seen the most experienced bowyers on The Leatherwall, TradGang, Primitive Archer, etc. address this stuff much. Some of the bowyers I respect most have touched on it over the years... and some of them are gone now... which has inspired me to try to better comprehend it... and apply it... so I can make good bows... and maybe help others do likewise.
Questions?
Ya know, p.s. if ya will... maybe I just think about this stuff too much. There's guys making good bows that don't give this sort of thing a second thought. What's the heck's wrong with me? :)
Jeff, On a lower wrist style grip, like what you and others build on these, wouldn't/shouldn't the "middle finger"(back side) and throat of the grip(belly side)(pivot) sorta coincide more or less in a horizontal line, for the balance point of the bow? It seems to me, anyway, this is where the balance point would and should occur?.......That'd sorta make sense to me given your philosophy and practice for tillering.....??
On the type of grip I like on my selfbows, BBO's and such, they're better suited to displacing the pressure more evenly across the hand.
Roy, is that your way of saying you couldn't follow me? lol
Ok who are you and what did ya do with Jeff? LOL
Until I see that, it's all hear say:)
It's time to get off the potty can and fess up here.:)
The balance point is found by measuring. The measurements I use were fine-tuned by trial and error, but originally I got close by what Dean wrote in his book.
Not all shelves are 1 1/4" above bow center. How far above center the shelf is located depends on the bow's overall length. I detailed this all in a post above... that you obviously didn't read. LOL
Not all bottom limbs are 1 1/2" shorter either... again, depends on bow length.
C'mon man... you messin with me?
I hope you detail your staining and sealing process. I'm sure there's a lot of good info to learn there as well.
I was shooting it last night and as I was retrieving my arrow, I flushed a hen mallard off a nest of eggs at the base of a pine tree IN MY YARD. There's a very small pond about 70 yards away. I hurried and mowed the grass while she was gone, then stayed away the rest of the day. I'm gonna try to give her the space she needs so she wont abandon the nest. There's been a skunk in my yard digging grubs the last few days. I hope he doesn't stumble upon the nest. I checked at sunrise this morning and she was back on it. I can see her from the bow shop :)
I just love messen with ya, Jeff:):)
LOL! And now ya got all the time in the world.........................look out Jeff!!!!!!! ;-)
I hope those eggs hatch and you have a bunch of little ones following that hen around...that'd be a real treat to watch.
Hope that pond ain't full of snappers too. Baby ducks have it rough from all angles - land, sea, and air.
Before we get into this here, keep in mind, she needs a name yet, and I'm ready to write it on there and spray it, so if something comes to mind... by all means, throw it out there.
Here is how I start this 'staining' process. I get an idea of what I want it to look like, and start mixing up some aniline dye... in this case, I'm using oil-based dye, because it doesn't flash off as fast and seems easier to blend the colors together on the bow. The "oil" I used is Naphtha, actually a solvent.
I didn't want the color to be so 'solid' that we couldn't see the grain of the wood, and the difference between the yew and the osage. I wanted more of a transparent dye in the end. I thought maybe brown at the handle, turning to a reddish, then to orange/yellow near the tips.
Here it is before steel wool...
The whole thing will darken up some when the finish goes on.
I'm going to have to make a new color-coordinated string now too. Three bundle brown, red, and yellow perhaps? :)
Now, unless you guys come up with a name for this here tri-lam, I'm going to go down and work on a yew stave... got one limb's sapwood thinned and chased to a single ring... gotta do the other one. I have high hopes for this bow... might be my hunting partner this fall. The stave came from Dean Torges... who got it from Dick Robertson. Maybe I'll finish the bow, hunt with it one season... and then send back from where it came... pay it backward :)
OK- I'll make a suggestion: How 'bout RUSTY? Since you said you like that antique look and it kinda has a rust color.
"About Time"
As in about time you build another bow, it's been a while bro!:)
I have Osage, I have a full length tapered cedar core lam, and I have Boo. I have black locust, walnut, elm, cherry, and hickory lams too. And Denny and I are both retired now. Pick a day we can come up and drink some of your beer. I'll bring an Osage split and you can help me get some nice billet slats out of it.
I'm leaning towards Raven, or, Meoquanee wich is Cheyenne for 'wear's red'.
Roy, any time you want to bring some wood up to grind pieces with the thickness sander and lam jig, for either tri-lams or standard BBO bows, you're welcome to do so. The wood's gotta be good 'n dry first so it doesn't move afterwards, but it does a superb job of it.
.....as a young man, I once met a gal who fit that description, but I was in a sleezy bar and she was sliding down a brass colored pole. Her name was "Destiny"......?
I gotta tell ya... she's laying here, sprawled out on my tv stand and her curves are more tantalizing than any bow I've made to date. Why am I gettin' the urge to dig the ones out of my wallet :)
I'm gettin' itchy to spray. I went with Raven, still could belong in that same sleezy bar though :)
The Thunderbird is mixed... and I'm awaiting the 30 minute induction time between Part's A & B while the compressor is building pressure and the studio is heating up. Then I've got to thin the mix, and it'll be time to spray... an anxious time for me. I've done it enough I should be more comfortable with it, but there's always some stress involved. Not thinning it properly or laying it on too thick can cause a run, or just one sizable dust gremlin landing on the finish can create a lot unnecessary work. I DON'T want to have to sand down a run or something and risk sanding through the finish into the dye job.
Without a designated spray area, or spray booth, I've found it works well to spray in the garage, with the floor wet down, and as soon as a spray session is over, quickly move it to the next room until the finish sets. Then back and forth until she's done. If all goes 'best case', I shouldn't have to sand or steel wool between coats... and it should be done by the end of the day. Wish me luck.
My garage, shop, house, clothes, ec all smell like sweet T-bird vapors right now. You don't suppose that stuff's bad for me, do ya? :)
I wasn't completely happy with the finish surface. It just wasn't smooth enough, so I sanded the whole bow with 400 grit to level the finish, steel wooled it with 0000 (probably could have stopped there, it looked quite nice) thinned the T-bird a little more, and resprayed. This is the 4th coat.
The hardest part is the waiting... 4 hours between coats and 24 hours until you can sand between them... tic-toc-tic-toc...
Finishing... my final frontier... the last bit of impatience bowmakin' has yet to choke out of me :)
Roy, get up here. I need help!
:)
Sand her down to bare wood and I'll bring My Stain and My can of Tung Oil... LOL:)
Your bow looks awesome. The lines are very similar to the one I mentioned to you is now ready for the skin backing over the sinew. This one is just 51 3/4" N2N, 48 3/4" strung. Haven't put it on the scale at all yet, don't know if I will. My body (shoulder) tells me it's a 'squeak' more than 50 lbs :)
I'm most likely going to put this one on hold to I get the second one started to the same point so as kin snake 'em both at the same time. Have turned my daily recreation hour to arrows for now. and on that note..
...am going to fully explore another coupla hair-brained theories I've had rolling around for more than a decade now. One would be starting with the arrows about four/five inches longer than my draw, since they are all primitive shafting. (Using, and preparing cane, red osier, rose, viburnum, and some really sweet black cherry shoots cut in 2005.) I'm fully prepared mentally (ha!:) to then reduce these arrows bit by bit from either or both ends to account for anomalies within the materials (despite no end of effort to 'tiller' them just as I would a bow limb, and match and tiller them to a perfection I never felt I needed to before, just because I want to this time :)
The other scheme I've had my sleeve is exploring something I read in an archaelogical journal years ago, in which the author 'theorized' prim peoples often made their arrows weight (fat end) to rear to more easily 'match' spine performance..and ironically enough, same article said arrows were left longer, (not 'in' the draw, but protruding) for two reasons. They stabilized much quicker (counter-intuitive by today's physics)...and they were more accurate in vegetation. (kinda the spear vs. 'bolt' concept)
Back in the late 90s I made a couple reverse arrows, although same length as my draw. I never finished my experimentation...but found they shot no differently than my contemporary wooden arrows, and I was pretty sure they were 'quicker'..but never got around to actually finding out for sure with a chrono. Didn't matter at the time...I was hunting with a longbow hard put to make 150FPS w/ 600gr arrow at the time :) I have no idea what happened to those five arrows...they 'disappeared'?
Enjoyed your thread(s) immensely!
ed
PS: have some more up-to-date photos of the bows in progress..haven't downloaded 'em yet...