Primitive Archer
Main Discussion Area => Bows => Topic started by: willie on November 29, 2024, 06:11:44 pm
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Zero set is the tillering goal.
What do you look for during the tillering process to see if you are pushing the wood too hard? Before the set happens.
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Set early on in the tillering process.
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I don't look for anything, to stop set during tillering, other than the basics(no weak spots, limbs bending equally, not stressing the stave over the intended draw weight).
All the work is done during the design and layout, to ensure there is enough wood, either by length, or width to minimise set. Add low moisture content, and possibly a heat treatment of the belly, and reflexing. Just make sure you stack the odds in your favor beforehand.
If you still get more set than you wanted, modify the design of the next one, until you achieve the results you want.
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the basics (no weak spots, limbs bending equally, not stressing the stave over the intended draw weight).
Add low moisture content, and possibly a heat treatment of the belly
the basics surely are a priority. Lets assume an experienced tillerer at work with good osage with a design that just asks too much for the wood.
Does anyone frequently unstring and monitor how fast the stave returns to straight?
If you still get more set than you wanted, modify the design of the next one, until you achieve the results you want.
All the work is done during the design and layout, to ensure there is enough wood, either by length, or width to minimise set.
Of course, if only there were a bigger supply of good osage staves waiting in the corner.
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Length, width, thickness, and belly heat, and being familiar with the wood you are working with, and slow careful tillering. We all know that, but it is worth repeating.
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To me it is mostly the quality of the wood you use, I have said before there is osage and then there is OSAGE, the latter being vastly different from the run of the mill stuff, heavy, very hard and cuts like butter with a drawknife with no splintering.
I have several bows that I made from this kind of wood 20 years ago that never developed any set at all.
Almost all of my bows develop some minor set over time and with countless thousands of arrows through them, I think this is inevitable and no big deal.
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At what point does set start coming in for most of you ?? For me about20”. If we was to build a bow never drawn over 20” would it most likely not take set? If I was to design a bow that draws 50# @20” inches would it be more likely not to take set??? Now in flight for example if you had more early draw and less draw length could it cast an arrow farther because it had more stored energy even though the draw length was shortened?
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At what point does set start coming in for most of you ?? For me about20”. If we was to build a bow never drawn over 20” would it most likely not take set? If I was to design a bow that draws 50# @20” inches would it be more likely not to take set??? Now in flight for example if you had more early draw and less draw length could it cast an arrow farther because it had more stored energy even though the draw length was shortened?
Good question. I wonder if what you are describing is more like an old style crossbow. Shorter draw but heavy early draw. I also notice set start to take place on my pyramid style bows and long bow at the 20” draw point.
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Zero set is the tillering goal.
What do you look for during the tillering process to see if you are pushing the wood too hard? Before the set happens.
I like to creep up on it doing the basics like others have said. Design, layout, moisture content, and most importantly wood selection quality. Avoiding early mistakes in process will minimize set but wood quality makes the difference like Eric said I believe also. That being said, Inexperience with top quality OSAGE can also take set.
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I like to creep up on it doing the basics.......
Avoiding early mistakes.......
Early mistakes are easier to see in simple bends.
When the limb has more complex shapes, ie deflex recurve/reflex or uneven limbs, The bowyer seeing the bends look even or consistent doesnt neccesarily mean the stresses are'nt getting to high someplace. Should a highly stressed area show set, well then we know, but I am hoping to find a way to see it coming before the set occurs.
How often have you lost alot of that nice "early draw" weight that makes for high string tension at brace, before set becomes apparent?
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I like to creep up on it doing the basics.......
Avoiding early mistakes.......
Early mistakes are easier to see in simple bends.
When the limb has more complex shapes, ie deflex recurve/reflex or uneven limbs, The bowyer seeing the bends look even or consistent doesnt neccesarily mean the stresses are'nt getting to high someplace. Should a highly stressed area show set, well then we know, but I am hoping to find a way to see it coming before the set occurs.
How often have you lost alot of that nice "early draw" weight that makes for high string tension at brace, before set becomes apparent?
you are right willie. more complex builds change things a bit. Especially with an unbraced profile that is filled with character for example would be more of a challenge for sure and this is where experience kicks in. The best way to get that experience is to build lots of bows and not be afraid to break them testing the limits an get a feel for it as well as an eye for good tiller. as an aside here i recently have been learning a lot more then previously thought about bamboo for bows and how to better tiller them. The lesson here for me is I guess we should never settle and always strive for better and possible new ways that may be an improvement albeit minor to what we have been doing. I came into bowmaking with no prior knowledge of working with wood or bending it. I had no pre conceived ideas or expectations. A buddy of mine made bows and I tried to trade hime a custome knife for one of his bows. I was surprised when he said no and said why dont you just make your own bow? Ive not looked back and still love it. There have been many one here and elsewhere that have helped me over hurdles that came up on various builds and learned a ton from this community. I do try to give back where I can to those i can. Wille you asked how i creep up on it on my builds and I would say that the yardstick method works well for me. I built my trade bow this year out of a very wonky yew stave that needed some taming. This bow went to Will B and it shot well and took very little set if any. I used the yard stick method on this build early on to get me to good clean brace. Once there i knew i was headed in a good way with this bow. I also paid very close attention to all the dips and hills and twists on the back to match them on the belly. I had a large cluster area of harder pin knots that had to be accounted for also as they dont bend the same as regular wood. I considered this bow a challenge and a joy to build and glad it went to Will. The yardstick method bassically takes overall bend of each limb independently for consistent bend and then comparing them with each other. using the straight edge of the yardstick laid accross the belly of the bow while bent to get a good view of the bend early on has helped me creep up on it. it dosent have to be a board bow either. Ive done this with character builds just fine and works especially well. I now use this method with my boo builds too. hope this answers your question Willie.
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thanks for taking the time to share, Dave.
I have been searching through some older posts that Steve (Badger) posted a while back. He developed what he called "no set tillering", and I even tried it a few times with some moderate success. Like most methods, there are judgements to make about how much and when. Perhaps I should do some test tillering to quantify just how much to back off my draweight goals when the method dictates.
http://www.primitivearcher.com/smf/index.php/topic,61588.0.html
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I try to get an even bend from the very beginning, bending the bow as little as possible. I can usually get to brace with no set by creeping up on things using gizmos but I really really struggle past 20”. Partly I think I might lose a little patience and start to rush a little bit but I also wonder if I tiller for too long and fatigue the wood. I definitely use wood with too high a moisture content I definitely do damage stringing the bow, more than once I have taken a bow past the point I have tillered to to get the string on
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I don't get in a hurry tillering a bow, it is a week project of shooting and checking for the slightest anomaly with my gizmo, I am only using 220 grit sandpaper at the end of the tillering process. I do reflex the limbs with heat before I floor tiller and have done some belly toasting on the last 5 or 6 bows that I made. I glue 2 1/2" of reflex in my bamboo backed osage bows on glue up, shot-in they are straight limbed or have about an inch of reflex. I can't explain my method for making these bows because it is mostly the way they feel in my hand at the shot and what my gizmo tells me. My design is always the same because it works, 64" NTN, 1 1/4" wide limbs with a slightly rounded belly transitioning to a round belly cross section about 8" from the tips
These are my personal bows with over a 20-year span, I have reworked a couple of them that had been shot tens of thousands of times and had some set, these were poundage drop rebuilds because I could no longer shoot them in my old age. I treated these bows like they were a new build with reflexing, wood removal, re-tillering and toasting the bellies.
The upper stactic has been my go-to bow longer than any other, at least ten years of constant use. It is still a great shooter but I may give it a lower poundage rebuild and resurrect it someday.
The third bow down is 20 years old and was made from the best osage I ever worked on, just a splinter with 13 small drying checks down the back that I filed with superglue. It has never had a heat gun on it and has the most rounded belly of any of my bows. It is 62@25, way too stout for me now.
The majority of the bows were made from that special osage I mentioned, I cut all of my osage in front of a bulldozer over the years so I couldn't be picky but knew when I found the great stuff.
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Very nice Eric. I bet there’s a lot of trial and error to get to that point.
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I used the yard stick method on this build early on to get me to good clean brace. Once there i knew i was headed in a good way with this bow. I also paid very close attention .............. The yardstick method bassically takes overall bend of each limb independently for consistent bend and then comparing them with each other. using the straight edge of the yardstick laid accross the belly of the bow while bent to get a good view of the bend early on has helped me creep up on it.
Hi Dave,
is this the yardstick method you mention above? seem to recall a post where you mentioned more about your method, but cant find it now.
http://www.primitivearcher.com/smf/index.php/topic,72512.msg1016923.html#msg1016923
perhaps
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I don't get in a hurry tillering a bow, it is a week project of shooting and checking for the slightest anomaly with my gizmo, I am only using 220 grit sandpaper at the end of the tillering process.
I got a few 1/2 finished builds in the corner from being in a hurry and gotta say that 220grit for tillering suprises me. 80 grit here.
when I take a break from tillering because my eye tell me two different things, breaking for another cup of coffee doesn't help.
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I should have mentioned; that 220-grit paper is on an orbital sander, not hand sanding.
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I used the yard stick method on this build early on to get me to good clean brace. Once there i knew i was headed in a good way with this bow. I also paid very close attention .............. The yardstick method bassically takes overall bend of each limb independently for consistent bend and then comparing them with each other. using the straight edge of the yardstick laid accross the belly of the bow while bent to get a good view of the bend early on has helped me creep up on it.
Hi Dave,
is this the yardstick method you mention above? seem to recall a post where you mentioned more about your method, but cant find it now.
http://www.primitivearcher.com/smf/index.php/topic,72512.msg1016923.html#msg1016923
perhaps
Yes it is the same. I’ll also add that I like to shoot 1/2 draw, 3/4, then full draw working my way up to full after several shots. This helps me get a good feel for the bow and sort out many of the inconsistency and anomaly that are seen and felt. I’ve had it that I had a perfect looking tiller balance visually going on at brace and 3/4 draw shooting only to end up with slight positive tiller because it felt smoother and shot cleaner. This is where the 220 grit paper comes into play I think too in fine tuning. I find this works well with my bamboo builds too not just stave wood bow builds. I also make sure I round slightly my edges and sand with 180-220grit after each wood removal in tiller process. Just how I do it. It allows me a clean smooth belly to visually pick up on any early issues.
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Whether a bow takes set or not is often decided before it ever bends. The bows are built either too narrow or wide enough to take the load. If your bow took set, 100% of the time it is because it was not wide enough to handle the stress. Even if the bowyer made an error in the tillering process and made a hinge, the bow is not wide enough to handle the bending load focused in that one area. While most would say, or its taken set due to the hinge, thats incorrect. The hinge is a thin spot and thickness controls bend radius, not draw weight. Draw weight, aka, set control, is 100% a factor of the bows width, ALWAYS.
So, if your bow took set, build another one thats wider. It will 100% take less set assuming the same quality of wood.
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So, if your bow took set, build another one thats wider. It will 100% take less set assuming the same quality of wood.
Hi Kevin,
we have all built another, and this type of learning gives us a better understanding, or maybe you would call it intuition or judgement. But the next bow is not always quite the same or comes from a different stave etc....
I hope to find a more quantitative approach to detecting the working stress limits of wood before the damage is done.
I think that somewhwere in between overbuilding with excess mass and the point where set shows you the damage done.... is a range of working stress.
Maybe for a hunting bow that shoots sweet with heavier arrows and gets the job done, this is not such a big issue, but I am seeking a method to help build a bow that shoots a very light arrow for flight shooting and needs to get the fastest limb speed at the end of the powerstroke -- A bow that retains and can make use of the high early draw weight so often lost before set shows its ugly head.
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Willie, for the last 7 or so years i have been looking for a way to do exactly what you are after. I think I have a formula that allows you to build a bow that takes no set. I have asked a few people to help me proof the formula and they are working on it. Once proofed Ill let the information be known, but I dont want to let bad info out, so please pardon my vagueness.
If you want to help, and you sound like a guy looking for the answers, you can tell me the wood you are going to use, the draw weight, and the bows length. Ill run the numbers and you buuld the bow. I find im right with about 5 to 10% margin for error. Im looking to tighten that up but some things are out of my control, wood quality, error in craftsmanship, etc.
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Willie, for the last 7 or so years i have been looking for a way to do exactly what you are after. I think I have a formula ......you can tell me the wood you are going to use,
If I told you birch or osage, would your formua use a book value?
While most would say, or its taken set due to the hinge,
but doesnt one have to know the correct bend versus "too much bend for the design"?
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Willie, for the last 7 or so years i have been looking for a way to do exactly what you are after. I think I have a formula ......you can tell me the wood you are going to use,
If I told you birch or osage, would your formua use a book value?
While most would say, or its taken set due to the hinge,
but doesnt one have to know the correct bend versus "too much bend for the design"?
Yes, there are book values for each different species already available that I plug into the formula.
The idea of too much bend for the design cones from the incorrect idea tgat thickness has anything to do with draw weight. You can thin a bowout unti the bow mends into a complete circle, if it has the correct width, it will take no set.
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Kevin we will get with you on one coming up. Finalizing the design.
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The idea of too much bend for the design cones from the incorrect idea tgat thickness has anything to do with draw weight. You can thin a bowout unti the bow mends into a complete circle, if it has the correct width, it will take no set.
I agree that too thick for the bend radius will cause set. I dont really understand what you are saying beyond that.
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The idea of too much bend for the design cones from the incorrect idea tgat thickness has anything to do with draw weight. You can thin a bowout unti the bow mends into a complete circle, if it has the correct width, it will take no set.
I agree that too thick for the bend radius will cause set. I dont really understand what you are saying beyond that.
I was in a hurry and had all kinds of typos. Your take away is the core of it all though.
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Willie, for the last 7 or so years i have been looking for a way to do exactly what you are after. I think I have a formula that allows you to build a bow that takes no set. I have asked a few people to help me proof the formula and they are working on it. Once proofed Ill let the information be known, but I dont want to let bad info out, so please pardon my vagueness.
If you want to help, and you sound like a guy looking for the answers, you can tell me the wood you are going to use, the draw weight, and the bows length. Ill run the numbers and you buuld the bow. I find im right with about 5 to 10% margin for error. Im looking to tighten that up but some things are out of my control, wood quality, error in craftsmanship, etc.
Kevin I have started a topic in the flight section where you can run your numbers on a bow we will build virtually. :)