Primitive Archer
Main Discussion Area => Bows => Topic started by: sleek on February 15, 2012, 08:39:57 am
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I am building an ash bow and am having early set issues. I have the bow 66 inches long, going for 25 inch draw and 35 lbs. After only floor tillering the upper limb only is taking set. I haven't pushed to bow past ( if even to ) brace height yet and don't feel like I am using undue pressure to get it there. ( I have made more bows than I care to count at the moment so I have a fairly good feel for the amount of pressure required. ) I am getting 3/4 inch set in this limb about mid limb. The limb is 1 1/4 inch wide there. I am wondering if anybody else has had problems like this? The bow has an even floor tiller and hasn't had a hinge there either. the ring count is 16 rings per inch if that helps?
I am worried about this bow ( despite its light draw weight, short draw, and long ntn ) taking excessive set. Is there something about white ash that I don't know? This wood was cut about 1.5 months ago, been in stave form for 2 weeks and bow dimensions for 1 week. I don't think moisture is causing this problem. I am trying to use heat to correct this problem and may even pike the upper limb and make it the stronger of the two to hopefully reduce its set. Any remaining set I will probably flip the tips just enough to cancel out. Any thoughts on my thinking process, or reasons/solutions to my problem?
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If I was gussing I would say it is to wet or still green. :) That's about all I know of that would cause set that early on. :)
Pappy
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I think your wood is too wet still. Let her sit for a few more weeks,and heat treat ash
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Its green. Give it at least 6 months stave form, 3 months bow form.
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Well, being wet seemingly the problem, I will give it a good warming over the stove for a a few hours. Not so much a heat treat, but fore sure get it hot for a few hours. Wish I had a scale to measure any loss in weight. That would help allot here...
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Toss it under your bed for one month. A quick heating over a wood stove wont do much at all.
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Leave it in your car when you go to work. Windows rolled up. that will dehydrate it.
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Yes its most likely high moister
Let it set another two weeks in the warm & dry then
with most of the white woods you can heat it up and drive it out at that point ,something that Osage does not like !
get it all warm enough to remove the bend you don't want & put in any you do want
Then the next day heat treat it , and it should stay put . just give it a day or two to settle in after heat treating !
Let us know how it goes!
Guy
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Ash is like hickory - it likes to be dry. It is also way stronger in tension than it is in compression. A perfect candidate for a fairly heavily trapped back. So at the moment your belly is even weaker than it will be when dry and unless the back is highly crowned or you have trapped it already it is giving a double wammy effect on the belly.
Ash respondes fairly well to heat treating but won't hold much if any reflex when unstrung.
Ash was the wood I cut my teeth on. When you know how to treat it it can make really nice bows.
What limb width taper have you got? Are you following the correct tiller for the width profile?
When you recurve tips you shorten working limb or to put it another way increase stress without having the option of wider thinner limbs to accept the extra bend so you will get more set in the inner/mid limb thus losing cast.
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I got a food scale. The bow weighs 590 grams. The length is 66.5 inches long, handle is 1 3/4 inches wide with the mid limb at 1 1/4 inch wide tapering slowly down to 3/4 inch tips. Does that sound like a reasonable mass with a stiff handle bow? About 8 inches of the center dont bend and the handle is 1 inch thick. Does the mass it has sound like it is wet or dry?
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I just got it to a low 4 inch brace and found the problem ( or at least one ) I have almost all the bending out the fades. What a novice tillering mistake, and to think I was stumped on it. oh well, I still want to know what yall think about the mass of this bow and its moisture contnet if yall have an opinion. Thanks!
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"This wood was cut about 1.5 months ago, been in stave form for 2 weeks and bow dimensions for 1 week."
Yes, it is still wet or green. If the wood is in bow dimensions, it needs about four weeks indoors to thoroughly dry. It can be done in one only if you force dry it in a heatbox. Putting it over the stove for a few hours won't cut it.
It is difficult (if not impossible) to guess if the wood is dry basing it only on the mass. If we have the volume as well as the mass, we can calculate specific gravity (density). But ash is highly variable, so the SG is not a solid number. Furthermore, the difference between a "wet" and "dry" bow stave can be as little as 5%, or in your case 30 grams.
Put the stave indoors in a dry spot. Weigh it every three days or so, and keep track of its moisture loss. When it does not lose any weight in a week or so, you're good to go. For now, do NOT bend the bow at all! Resist the temptation...
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Well thanks for the advice again. It seems as though between my last post and yours, I took the bow out and tillered it to 30 lbs at 22 inches. I hate to make it sound like I didnt heed good advice, but I really thought the bow was just bending to much in the fades. Actually I know it was because thats the only place there is set taken place. I got the limbs bending much more in the mid and outer limb.
I will place this on a form and take advantage of all the set in the fades and make it a deflex in the handle and reflexed mid limb bow. Heat treat that in then let it sit for a week and see what happens. Hope it works out well. I now need a moisture meter. Thanks for the advice guys, and please dont think I just ignored it, again, I saw all the bend in the fades and figured my set problem was there.
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Moisture meters are pretty much a waste of time.
You need a humidity meter with a thermometer.
Look in TTB for the relative humidity/temperature scale. These things combined will tell you for definate when it's good to go.
Or just use feel. ;)
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Thanks Mike, I will see about that set up. In the mean while, The bow is now at 520 grams after tillered to 30lbs at 23". It lost allot of weight. It comes out to 18.34 ounces. Going by the TBB IV page 92 on the mass principle, Shooting a 66 inch stiff handle bow at 30 lbs draw weight and 25 inches of draw ( my final tiller target ) I should be at 13.5 ounces.
I am still 5 ounces to much, but I have yet to narrow my massive tips and rech that last 2 inches of draw length. Apparently I have aslo to let the wood finish curing. Oh well, I reckon one week wont hurt anything. LIke I said, I am going to tie it to a form and shape it to a deflexed handle with reflexed mid limb design. More to come later. Thanks again...
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If you incured set from floor tillering then your wood is too wet...simple as that. It doesn't matter where your set incured and if you had a lil too much bend in the fades. If it was dry it wouldn't have taken set at that point in the ball game. And if your tillering per mass then your gonna come in too light after it dries out,and it will be susceptible to breakage. And if this was a bow I was making for someone and selling it to them,then I would wait and let it dry out. It only takes a couple ounces from floor tiller to finish tiller if only removing wood from the belly. And your already almost at finish tiller,and you'll only lose a half ounce at the most there,and an ounce or two removing width from your tips at the most. And since you have 5 to go it tells me your wood is too wet. Call me a jerk n hate me,but it is what it is. Green ;)
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I promise you it is still wet/green. :o If you are determed to carry on then go for it but be aware you aren't going to come out with the best bow the wood could give you if you would just give it some time. :) Been where you are and done what you have done and learned better. :) :) Good luck .There are ways to quick dry wood but none better than time.Patients. :)
Pappy
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Trust me. Been there. Done that. You're stave is wet. Wet wood cracks if heat treated. Jawge
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I say carry on. That way when this comes up again you will have experinece to answer the question for somebody else. I learned ALLOT doing what others told me not to do because they already have.
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OK I'm sorry, I will stop for a while. Onto the dash of my truck it goes. And Gosh Blackhawk, your such a jerk ;) joking of course. I can be a bit hard headed sometimes. Is it to late for this bow to be a good one? Am I wrong for thinking the option to pike it is there if I come up under mass and retiller once dry?
Sorry for being such a nuckle head guys and thanks for the posts everyone. What I will do in the meanwhile is just rough out a few more bows. Impatience is what some would call it, but really its not. I just cant stand to not be working on a bow all the time. Waiting sucks. Think I will break out some honey locust and play with that. Thanks a gain, feeling kinda sheepish right now.....
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Let it dry for at least 4-6 weeks. Heat treat it with 2" of reflex and make a killer bow. Just dont bend it anymore until its dry. The more you bend green wood the more it collapses and wont come back.
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That is what I will do. Got it drying right now. Thinking of making a solar stave cure box....
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if you have forced air in your house then just stick it in a heating duct,and carefully monitor it each day
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!
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Forget the reflexed mid-limb idea. Ash won't hold the reflex without a backing.
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What about mild flipped tips?
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All that is going to do is decrease working limb thus increasing stress without the option to widen the limbs so that they can take it.
It won't help the outcome. If you want to make a 'flipped tip' bow then you need to design it as one from the start.
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Ok, so let me ask you this, how does ash heat treat?
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Its a must in my book.
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Ash heat treats beautifully, in my opinion, but only when the heat treating is done to dry wood that hasn't been damaged by excessive strain while it was still wet. You can heat treat your bow, but you aren't going to fix the set with a heat treat at this point. You damaged the wood when you bent it green, and damaged wood will stay damaged regardless of what else you do.
The order of operations that I use on all dense whitewoods that I commonly use (white ash, white oak, hickory, hard maple) is:
1. Cut stave
2. Reduce stave to about 1 inch thick x 2+ inches wide x full length
3. Allow stave to dry for 6 months
4. Reduce stave to rough-bow dimensions
5. Allow stave to dry for at least 1 year, ideally longer
6. Reduce stave to final width dimensions
7. Tiller until the bow can be braced, then heat treat the bow's belly
8. Keep tillering, heat treat when you reach 1/2 draw, then again at full draw, then again when you reach your desired draw weight at full draw
I can usually minimize and occasionally eliminate set with this process. As someone else noted above, there's no substitute for patience. I'm not a fan of force drying anymore. I've gotten good bows from staves that were forced dry, but all of my great bows came from staves that were air-dried for years.
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I may have to call this bow a gonner. The bow through force drying has dropped to 17.8 ounces. I had forced dryed it all these last few days. There has been a spot in the fade that I havent given much thought too because I had no clue it would cause me a problem. A small 2 inch section right near the handle is starting to delam between the rings on the side of the bow. Not a check on the belly or back, but a delam in the side 1/3 up from the belly to the back, but closer to the belly.
A few chrysels have formed there running 1/4 inch towards the center of the belly where this delam is. I guess this is how deep the delam runs. I have tried to fix it by filling the crack with super glue, poking small holes around the chrysle to relieve it of compression stress and burnishing it back down, but at brace they come right back up. I think I may cut this delam out and reglue a piece in, trap the back a touch to take compression stress off it, heat treat that section up good and brown, or a few other things. Any ideas?
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i was able to stop it by poking deeper holes and reburnishing.
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Don't try too many new techniques on one bow until you've done some of the basics, else you will just end up confusing the cause and effect.
Keep it simple, one step at a time.
Del
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Good advice Del, but what elsce could I have done? I want this bow to be able to survive, and last a very long time.
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Let it dry Sleek. The growth rings seperated because they werent dried down. My buddy did the same thing with an white ash bow last summer because he was in a yank, rightfully so. It chrysalled and seperated the same as yours. Ash being very strong in tension the bow still shoots. But it has 4-5" of set and is a total dog. If you REALLY want one your ash bows to last, let it dry at least 6 months as a 2x 2 stave and 6-8 weeks roughed out after that. It will yeild a classy, durable ash bow if you do your job well.
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I want this bow to be able to survive, and last a very long time.
I think you've already eliminated that possibility. I'd start on another stave, and let it dry and season properly this time.
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Ok, starting on another stave. I will ( just for the heck of it ) check the draw weight , retiller a touch to make it a bit more bendy mid limb and outter to remove some stress of the inner fades. Then shoot the snot out of it to see what happens.
If it doesnt break, i would like to send it ( i will pay shipping ) to somebody who can give me an evaluation of the woods condition, to include moisture content.
This bow now weighs 17.8 oz.
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I want this bow to be able to survive, and last a very long time.
I think you've already eliminated that possibility. I'd start on another stave, and let it dry and season properly this time.
Then go cut split and rough out another stave, then one more ;) Then your first will be ready to take to the next step and so on. Think production line and ground work and it will mean you never have anything to work that isnt ready to be worked on. Also helps to walk away from a stave, go work on another and let your brain do the working out over time.
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In my experience, making high quality wooden bows doesn't lend itself to the mentality of a production line.
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Here are some images. This bow is slow, but hey, who didnt see that coming?I did get the chrysles taken care of however. Here are some images. I got 145 fps out of it with a 270 grain arrow pulling 25 inches 30 lbs with 2 inches of set. I will heat temper the belly from the fades to midlimb to see if I cant erk a bit more speed out of it by trying to take out the set.
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1443.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1442.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1441.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1438.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1436.jpg)
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all i gotta say is grow the beard back.. 8)...thanks for the pics
and talk to pearl about trying to remove set from a bow with tempering. he did a pretty good experiment with it.
whats the width?..sorry if you already mentioned
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LOL blackhawk, my wife is not a fan of yours at the moment for the beard coment, she hates it!
It is 1 1/4 inch wide at the fades and pretty straight all the way to where the tips start to narrow.
Maybe Pearl will volunteer some info here as he already has a few times. Assuming my hardheadedness has not irritated him enough already ;)
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Your tiller does not match the front view profile of that bow. It should really be more elliptical where now the inner limb is doing most of the bending. 2 inches of set isn't really that bad and for the weight and draw length I'd guess the dimensions are suitable. Probably got some early set from not being dry and also having most of the work being done by the inner limb. As far as I know heat treating is a suitable option for ash if you wanted to consider that option.
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Why should this be a more eliptical tiller?
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As for front view profile effecting tiller shape, while they aren't dependent on each other, front view profile will tell you the optimal tiller for best speed. The relationship is that of mass and movement where the less massive parts of a bow move the greatest distance because they are the easiest to move. A pyramid bow with even taper has circular tiller because the mass and width decrease evenly along the limb. A flat bow with limbs full width to mid limb will have elliptical tiller because the inner limbs shouldn't be moving as much because this causes the rest of the mass in the limb to move a greater distance. In the case of the flat bow versus the pyramid, the flat bow has more mass mid limb and that area should not move as far thus creating the elliptical tiller.
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Thank you ryoon, I will be making the adjustments and repost. I know this will drop the draw weight, but a good limb toasting should bring some back. If I have to, Pike it 2 inche.
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Thanks for the info...I also think your a tad narrow for ash...good thing its light weight,otherwise it would've taken more set.
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Ash can be narrow as long as it's dry and well seasoned and the back is well rounded, in my experience.
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Maybe Pearl will volunteer some info here as he already has a few times. Assuming my hardheadedness has not irritated him enough already ;)
Who says you cant figure out somebodys personality without ever meeting them! :) I dont get irritated sleek, I just quit typing buddy!
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Looken good get it hot and see what ya have then !!
Guy
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HaHa, pearl, I like that quote and may use it sometimes.
Tonight when I get home I will probably put the bow on a form, wrap in a wet rag with some foil and steam it into a reflex inner and mid limb. After that has been done, let it dry for a day and then go back on the same form and toast it till it turns a light brown to help lock the weakened fibres in place. I dont expect it to hold the reflex, I am only putting it in in hopes of it making the bow come out straight to get the set it has out as the stave was straight to begine with. We will see what happens.
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I have a bad feeling about toasting it. I hope it doesnt split all to heck on you.
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Definitely report back on what happens with your heat-treating experience. I'm sure we'll all learn a little something from it...
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I hope it comes out ok, but if it splits, or breaks, or does the macarena ( I want bow of the month if that happens ) it will be ok. I know I have done allot of things with this bow I shouldnt have, impatience and curriosity being the two biggest driving factors here, but I have decided that this bow is either going to put up with what I do to it, or break. Either way, something is going to happen and it may be interesting :D
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The best part is you recognize it sleek. At least you know what you did wrong and can make it right next time. That in itself is invaluable. We can all bark what we want, but what you actually do and see on your own will hold more weight than any of our mumblings.
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Please Pearl, dont take what I do as me asking for advice and then ignoring yall. Often times I ask questions about something I am going to do to see what to expect, plan for it, and try to avoid negative outcome. This bow build for example.
To be honest, I thought the wood was dry enough to start making a bow from to begine with. However when you guys told me it was to wet, I wanted to see if and how to make a bow from one that is to wet by trying force drying ideas. I got the bow to stop dropping weight with all the force drying.
Then I started asking questions to find what to expect on the steaming of the wood and heat treat to remove set. I am doing it, but wanted to know what you guys had seen go wrong so I can try to prevent that from happening to me. Not by just not heat treating it to avooid it, but do it in a different manner to prevent the negative outcome experienced in the past.
Often time I ask a question, get the answer, then ask why that answer is true. I dont want to know just what to do and not to do, but also understand why. I feel if you can understand the entire process rather than just knowing it, you can work around obsticals better and force the outcome you want from a situation more accurately. Doing things folks dont recomend is how I like to do it. Its like a challenge. everybody knows a dry piece of wood makes a better bow than a wet one. So I want to figure out the fastest and best method to go from wet to dry bow, and cancell out all the negative effect of doing so.
Sorry for my hardheadedness, but for me, this is fun :)
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I steamed in 2 inches of reflex and it held when I took it off the form. I braced it at 7 inches ( kinda high I know, I need to adjust the string a touch ) and pulled it back about 12 inches a few times. It seems to be willing to hold the reflex so far, but of course, 12 inches is no where close to 30 lbs. I am now toasting the belly to lock those fibers in. Afterwards, retiller and shoot it in... The bow may survive yet. It has taken allot of early draw weight too by the way...
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Steaming dries out the wood. It will make it (temporarily) very weak and brittle. You really mustn't draw the bow until the wood has re-hydrated for at least three/four days (preferably a week).
You are doing very good in trying to break the bow :) I know you can do it; just pull it to 28" and watch the splinters fly!
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LOL, Not really trying to break it, just trying to see where the line is. I ask questions to figure out what yall think about what I am/will be doing, then try to do it with your guys ideas in mind to avoid the nagative ( breaking the bow ). I'm just walking the line as fine as I can get.
Darksoul, I was banking on the woods moisture contnet being so high to begine with to keep it from drying out too much. I figured since the stave was so wet to begine with I would be safe with messing with some heat. As of right now the bow weighs 15.8 ounces. I have taken allot of the tips in width, actually I reduced them by about half since I last weighed them. I will let it sit one day in my garage to see if it gains or looses weight. Then go from there. If it gains weight, then I assume I over ryed it and it needs to stabalize. If it looses weight then I assume it isnt all the way dry yet. If nothing happens, the I will give it one more day then make a decision.
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All most there !!
Do you use oil when you heat treat ?
Guy
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No I dont use oil, never have, and never looked into why it is used. I always use steam and then follow with dry heat.
Another question for those not completely ready to report me for being blatently anoying . I need a bit more bend in the outter limbs to get a more elyptical tiller. O course I could take bore off the belly as I have been doing. I could make it thinner in that area to reduce mass, but I dont want to reduce the area of the back for no other reason than I want the back wide.
So this leads up to what if I did a combination of both, and made the belly start off flat in the inner and mid limbs, then slowly start reducing the corners ( which are rounded off by the way ) into a rounded belly in the outter 1/3 of the limbs? I think that would reduce mass significantly, increase the outer limb bend, keep the back wide ( for safety ), not allow set so far out on the limbs, and make it look neat :) Any thoughts, Or has anybody seen this combination of a flat belly tapering to a rounded one tiller before?
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I think that would [...] not allow set so far out on the limbs
Set occurs in the BELLY of a bow, not the back. Wood cells get compressed which causes set. Since a rounded belly put more pressure on the belly, this is more likely to take set. A rounded belly actually allows for more set than a flat belly.
In your case, however, the rounded belly will be near the tips. Set is far less devastating near the tips than the fade near the handle. Set near the handle would cause the tips to deflect more (like a lever), effectively creating more string follow. I wouldn't be afraid of the bow taking set in your situation. The bend in the tips should be minimal anyway, so set is even less likely.
The ideal tips are not wide and flat, but narrow and fat. The last four inches of the limbs can easily be 3/8
" wide (=narrow). A round cross section is perfect there. Even classical flatbows with flat bellies usually have rounded limbs for the last 8" or so.
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Just after being unstrung she holds 1 3/4 inches of just unstrung set, is 30@ 24" ( leave that last inch of draw for set to take up), weighs 15 1/4 ounces, and most importantly, is in one piece. I will start the shoot in process tomorrow. It involves about 5-10 partial draw ( to get the feel of it ) shots, then 100 full draw shots, chrono speeds, reweighing, and any mild tiller corrections.
That heat treat was intense. It put back down to 30 lbs at 20 inches. I was able to remove allot of mass and make some ( what I hope) wonderfull tiller corrections on it. Pics up tomorrow of the new tiller. In the meanwhile, here is the tiller immediately following the heat treat.
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1476.jpg)
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Darksoul, We posted togeather. The last 4 inches of my tips start out at 3/8 and taper down to 1/8 at the very tip.
I think we were saying the same thing about the set in the outter limbs. Everything you mentioned is exactly why I wanted to round the belly in the last 1/3 of the limbs. I started the belly rounding at 15 inches from the tips, gently getting more rounded as it gets closer to the tips.
I am not exactly sure what I said gave the impression that I thought a bows back causes set. I know its the collapse of belly fibers, thats why the heat treat was so important. Thanks for your thoughts, they are exactly what I wanted to hear.
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go shoot it
Guy
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I have finished the tiller. Here it is, tell me what yall think? I came in at exactly 30 at 25 inches, me target draw weight and length. All I have left to do now is stain, varnish, and complete the shoot in. By the way, as a lesson to attention to detail, make sure of which end is up before you carve the handle!
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1479.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/ashbow1tillercheck.jpg)
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Opinions welcome? Or did I drag this out to long?
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It's not elliptical!
A picture of it unbraced to see where the set is would be good.
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Ok, so I thought it was, how would it look if it were eliptical? I thought the circles drawn showed it was? Confused?
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@Mike: Isn't elliptical kinda flatish in the middle and a little whippy on the ends? Like, half of an oval, verses half of a circle? I don't know. Sleek, I think your bow is pretty nice lookin. A little bit weak on the upper limb, of course I'm sure you know this. Well done. :laugh:
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I thought that each limb had to follow the arc of a same size circle? It was my first time trying this and thought it came out good? It holds 1.25 inches of set, bottom limb holds 1 3/4 and top has 1/4 inches. The reason for the difference is one limb, the bottom, has a wave int the grain at the fade pushing the limb into an early deflex. I will take a pick of the sister stave that I ripped off from its side to show later. I just averaged the two limbs set to get what it actually took between the two.
Here are some glamor shots :) Proud of how the bow came out looking. And in the first photo, that tail is attatched to my husky, not me :)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/ashbow1finish.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1564.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1567.jpg)
(http://i1092.photobucket.com/albums/i411/rocketernally/ash%20bow%201/IMG_1568.jpg)
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Sorry for the over photo post, trying to edit the pics some and screwed up.
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Ok, why are my images making me look like a fun house mirror reflection?
Chrono speed with a 270 grain arrow is 140 fps, not fast, but adequate for a target bow.
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Seems to be some auto-dimension sizing going on there bud. Looks like a lovey bow though.
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Thanks dwardo. How do I fix this auto make me look fat sizing thing going on?
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nice bow, i use photo bucket and it sizes the pics for ya, are ya sure it's the pics making ya look fat >:D, if so i'll use that excuse to, Bub