Primitive Archer
Main Discussion Area => Bows => Topic started by: willie on December 08, 2013, 02:40:13 pm
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Hi all
I am new to all this and have recently broken a couple of hickory boards trying to make them into bows. My basic method was I followed instuctions I read about exercising the bow alot to let the changes take affect before scrapping some more, but the boards have broken just before or shortly after reaching 28" draw. I can see that I need to have them closer to finished thickness earlier in the process, but most of what i read is bend a little more here a little less there as you go. But all this is after you floor tiller, and some of the threads say they dont even do that, but some of the guys say that they are just about done with the bow after they tiller it to brace height?
It seems that the art is to get the bow right before you pull it to far, but I dont find much to read about how to know how much it takes to get it bending in the beginning. It's like you have to build it before you can build it. If I want a bow to be say 50# when I am done, is there a forumla to know how much it takes to bend it the first 6 inches?
willie
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Hi Willie, good to have to aboard. Check out this recent thread.
http://www.primitivearcher.com/smf/index.php/topic,43740.0.html
You're going to get good and bad hickory. Mostly depends on how it was stored and processed. Good idea is to do a bend/break test on some scrap before starting your bow. Good hickory will take a great bend without breaking. Mostly it'll collapse without snapping into. Bad stuff breaks clean. Good luck with your future bows..........Art
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Willie, thats the same question almost all of us have when we are getting started. It changes pretty radicaly with the length of the bow you are building and the style to some extent also. There was a similar question yesterday. I went and measured a 50# finished bow on the long string just so I could answer him. The important thing to remember when working with a long string is that the poundage reading you are getting has more to do with how far your string is hanging down than it does the deflection of the limbs. It is very important to try and get it bending as even as possible before ever bracing it. Try not to pull it any further than what you need to pull it to see an area that needs some work. If your long string is hanging down about 6" if you just take your finger and remove the slack it should probably read about 40#@21" and you should be ready for a low brace height. When you are excersizing it just don't pull it over 50#, less if you can see where you need to work it.
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Badger
yeah, that was me that asked yesterday, and your advice is where i am going to start on the next board.
Aussie came back with a method that was quite different, but since I started aksing about floor tillering in your thread about your spreadsheet, I thought I would move the question to a thread of its own and see what kind of variety people have with their floor tillering.
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That same question has always been lacking in a real solid answer. After you build awhile you will start doing it more by feel. Next long bow I build I plan to take some measurements and write it down.
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Willie, after over 30 years of building wood bows I still floor tiller to about 4" of tip movement. This allows me to be sure both limbs are bending at lease somewhat together and that their weight is in the ballpark with each other. I then go to a long string just longer than the bow. By the time the tips move 8" on the long string and both limbs are bending evenly and together I'm usually ready for a low brace of 3" or so. At this first low brace my main concern is that the string is tracking well. If that is the case I continue on removing wood, exercising the limbs(gradually and not too far for now) and checking tiller. When I get to 14" or so of draw length I start checking my max draw weight and only draw to that weight until tillering is complete.
Getting everything bending well early on will help you stay on track with the tillering and achieving the draw weight you desire. Ideally you want your tiller to be right on and your last few inches of tillering is only for weight loss.
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I've been discussing this with someone else and I posted my thoughts on my blog.
http://bowyersdiary.blogspot.co.uk/2013/12/yew-stick-bow-and-draw-weight-to-brace.html (http://bowyersdiary.blogspot.co.uk/2013/12/yew-stick-bow-and-draw-weight-to-brace.html)
There is plenty of tillering on the blog and if you go back about a month you can follow the tillering of a 130# warbow and all the trials and tribulations on the way.
I make a point on the blog of showing my mistakes too, so you will find some blow ups too... they may make you feel better! This one was a warm up for the 130# bow.
http://bowyersdiary.blogspot.co.uk/2013/07/warbow-explodes.html (http://bowyersdiary.blogspot.co.uk/2013/07/warbow-explodes.html)
I get a bow roughly even taper than get it on the tiller tree. IMO it is a mistake (certainly with a stave) to try and get it finished before you've started! Biggest lesson you can learn is patience... it's not a race... you've got to remove a certain ammount of wood, but there's no time limit on how long it takes you. Only experience will let you rip into it early and get away with it.
Good luck
Del
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If you have a manufactured bow try bending it on the floor to get afeeling of what your after.you could even put it on a tillering stick ,feel the weight and observe the bend.very true what art said about hickory in board form being hit and miss!good luck!
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Thanks for the replies, guys
Pat,
By the time the tips move 8" on the long string and both limbs are bending evenly and together I'm usually ready for a low brace of 3" or so.
so for say a 50# finish design, do you pull 50# to get that first 8" b4 you brace?
willie
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Thanks for the replies, guys
Pat,
By the time the tips move 8" on the long string and both limbs are bending evenly and together I'm usually ready for a low brace of 3" or so.
so for say a 50# finish design, do you pull 50# to get that first 8" b4 you brace?
willie
Willie, if your string is real short and you pull 50# to get it braced you might still be a bit too heavy, If the string is hanging down to about 5" or 6" then you would probably be ok.
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I just did another little experiment. I used a string that was very long and hund down to 13" on a finished 50# bow. It still read 50# @ 27" about the same as it would hve read had I braced the bow and pulled it the same distance. If you put any length loose string on your bow and it pulls about 50#@say 19" then thats about where it would pull if it were braced and not having a loose string.
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If you have the tips moving 4" at floor tiller check it on the tiller tree with the long string and see how it bends. You are stressing the bow very little at this point. Work your way out to 8" slowly, exercising as you go. When you hit 8" be sure both limbs are bending close to each other and both are even in weight. If everything is OK low brace the bow to 3" or so to check how the string tracks. You will also get a true picture of tiller at this point. From now on don't pull the 50# bow past 50# as you tiller and exercise.
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Badger & Pat,
Thanks for taking the time to help me with some real numbers. Just one more question while we are on the subject.
I got one 70" hickory board that I have reduced to about 1/2" thick at midlimb that has since developed a 2" recurve.
Its been set aside until I get a better feel for floor tillering, but I can tell that it wants to take quite a bit to bend it over center to start going the other way, and I read that it is quite easy to be fooled early on when working with reflex or recurve limbs. With a board or stave like this would you tiller it out further with the shortest "longstring" , before trying to brace it?
willie
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Willie, how long was the stave? Was it straight grained? Did you glue on a piece for the handle?
A big part of the battle is choosing the proper stave. That was what I did not do when I started.
Anyway, consider making a bend in the handle bow. No glued on pieces. No narrowing of the handlea rea.You can leave the stave 1.5 in wide for 50-55# or you can rip the stave to 1 3/8 in and get 45-50...at least potentially anyway.
There is a red oak board bow buildalong on my site. Check it out. You can still use hickory.
Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/boardbowbuildalong.html
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George
I assume you are asking about the ones that I broke in the opening post. they were 4/4 boards about 68" x 1-5/8 wide long with stiff glued on handles. I did finally get a bow out of one, but it was tortured to 28 and shows some set.
As for the board mentioned in the post above your reply, it is a 3/4 board x 2- 1/4" wide with a 1/2 thick glued handle, and might have to become shorter bow, as I roughed the limb a little thin in one spot mid limb. It has developed 2"reflex after roughing the limb to thickness. yes it has nice straight grain hickory. Just trying to get a feel for floor tillering before I pull it too much.
willie
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I usually start with 72" long staves to make 66" long stiff handle bows. I don't shorten the stave until I can "short" string it and even shoot it for a while. I also don't worry about set. If it bothers me too much, I can always "flip" the tips or reflex the bow with heat. I also leave the stiff handle area quite long, say about 12". If necessary, I can shorten the handle to adjust the tiller that went horribly wrong. I can "cheat" like this because I only try to make shootable bows, for now.
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I usually start with 72" long staves to make 66" long stiff handle bows. I don't shorten the stave until I can "short" string it and even shoot it for a while. I also don't worry about set. If it bothers me too much, I can always "flip" the tips or reflex the bow with heat. I also leave the stiff handle area quite long, say about 12". If necessary, I can shorten the handle to adjust the tiller that went horribly wrong. I can "cheat" like this because I only try to make shootable bows, for now.
All the things there allow you to mess up and then maybe still get away with it. None of them are good ideas if you ask me...it's like setting out knowing you are going to fail and also way more work than is needed.
If you can't tiller without using all these measures I would suggest starting out with a definate length in mind, cut your stave to this length and just go slowly until you don't mess them up anymore. :)
The tiller of a bow doesn't just 'go horribly wrong'.....you remove too much wood or leave an area too stiff. It doesn't 'just happen'. ;)
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I usually start with 72" long staves to make 66" long stiff handle bows. I don't shorten the stave until I can "short" string it and even shoot it for a while. I also don't worry about set. If it bothers me too much, I can always "flip" the tips or reflex the bow with heat. I also leave the stiff handle area quite long, say about 12". If necessary, I can shorten the handle to adjust the tiller that went horribly wrong. I can "cheat" like this because I only try to make shootable bows, for now.
12 inches is a massive stiff handle for a self bow. You are losing several inches of limb that could be bending without gaining any real benefit.
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I'm my only customer. Therefore I just do whatever I want with a stave at the moment. I tend to prefer rather long bows with a "massive" handle. More often than not I just keep them 72" long. Hence most are just shootable but unfinished bows. There are some benefits for long handles especially if you mainly shoot at targets. My tricks are not for any serious craftmen. They are for the beginners who are very much anxious to have a shottable bow with limited time and skills. I might even start to sell my shootable "staves" for $20 each. ;)
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I consider this the ultimate beginner board buildalong. Maybe it will help you.
http://www.primitivearcher.com/smf/index.php/topic,37695.msg499029.html#msg499029
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We all learn by getting bows under our belt and listening to the voice of experience. Read all you can get your hands on. The process never really changes much. You just get faster at it. There's a few basic rules though. Here's what helped me.
Grain and ring orientation are two very important things. Each wood species is different. Read all you can about them.
Never pull past the intended draw weight during the tillering process.
Keep the limb tips on the stiff side. You can get them to move later if you want.
Make a tillering gizmo, until you develop an eye for tiller, then keep using it because it's a great tool!
Faceted tillering is a more predictable process.
Excercise the limbs without overpowering them. You don't have to max them out to register change.
Perfect tiller isn't just a pretty arc. It also means that the limb tips arrive home in unison.
Don't hurry. Speed will come. You'll find yourself starting out with less material on the limbs when you begin tillering.
Sandpaper is a good tillering tool too. It has a side benefit of giving the finishing process a head start.
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The way I've been able to get the least amount of set is using badgers 'no set tillering' method
Now woods that are likely to take set will. That's the nature of the game. But this method helps you detect the set as soon as possible, and then you can deal with the problem right away. It took me awhile to understand the process but once you get it down it becomes part of your tillering technique.
This is my method.
1. Try to nail the thickness taper on the bandsaw. And running my fingers along the limbs and taking out all the high spots and leaving the low spots alone to get a nice taper.
2. Floor tiller about 4" of tip movement (takes awhile to get a good eye for that)
3. Put on long string(sting just long enough to reach end to end)
And pull 2" at a time, teaching the wood to bend early on. Always sanding and removing tool marks after EVERY wood removal.
4. Brace, make the brace profile as perfect as possible.
using the no set tillering method all the way to full draw. I pull 5# above desired weight that way I have a little room to finess the tiller if need be.
Here is the link. Took me a couple reads to 'sort of get it'
But on e I talked to weylin and Carson it all became clear. And I'm sure steve wouldn't mind if you asked questions about it either.
http://www.primitivearcher.com/smf/index.php/topic,17294.0.html
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Grain, grain, and grain are the 3 most important things for board bows. Willie, I humbly ask that you check out my site and check my last post again. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/index.html
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All very nice heuristic rules. A lot would depend on your level of skill and commitment. For record seekers, most of the rules are not good enough. They would try to refine them and also spend a lot of time trying to find the perfect stave. For expert bowyers, most of the rules are followed almost by instinct. I suspect they would also spend a lot of time and money for good staves. For amateur tinkerers like me, what matters most is the design and probably not execution. I can make a shootable oak selfbow in twenty minutes with a bandsaw. Most of them would shoot 150FPS without any problem and that is usually good enough for hunting. I guess all depends on why you bother to tiller a bow for yourself. I mainly do so for exercise. With a straight stave and a block plane, I just whittle wood till it bends enough to shoot an arrow. Just one rule -- long strokes. No matter what you do, enjoy.
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George
I have read quite a bit at your site, and find it nice to be able to go there and have one place to go to get the info one needs. Sometimes looking through forums can get you going the wrong way, as it may be hard to separate the wheat from the chaff.
I also checked your previous post, and I guess I am not sure if it is a response to my post directly above it, or the opening post.
willie
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This is not aimed at Jawge. I would not, especially on the internet, take what you find from one source to be gospel. If you see it on 2 or 3 sites and they are not duplicates of one another you're probably OK. Just because someone can operate a video camera does not make him an expert boyer. Now Jawge deserves respect, after all he has the respect of all the people on here. Take a hard look at where you're getting your info from. But you probably know all this.
Don
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Tom
thanks for the helpful tips. I will have to try to facet more, as I have not been doing that and I did not know that I do not need to max out the bow when exercising.
You'll find yourself starting out with less material on the limbs when you begin tillering
This is my goal, as I have read that some guys can bring a bow to brace height , and just about be done. It seems that all the bow torturing that happens by starting to thick, can be avoided.
thanks
willie
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Bryce
your explanation gives me some pointers that I have not heard before. Thanks :)
But on the other hand,
Try to nail the thickness taper on the bandsaw.
Floor tiller about 4" of tip movement
Brace, make the brace profile as perfect as possible.
These parts of the process are more like goals to me than instructions, but of course you mentioned that.....
(takes awhile to get a good eye for that)
so opened this thread with the intention of learning more about how that is done.
Perhaps I can ask my question another way.
If I have my bow bending about 6" on the tiller tree, what should I be seeing and feeling so that I do not have to overwork it inch by inch to final draw length?
willie
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A great saying that helped early on was "The sooner it starts looking like a bow, the quicker it will start acting like one"
Thickness taper is key. One thin spot and the stress will start to show quickly. When you notice this then the rest of the bow has to fall in line with that one spot, no way to ignore it, just accept it and adjust your expectations accordingly. This is why it helps to make it look like a bow early on. No tool marks or places that problems can hide.
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When I get to 14" or so of draw length I start checking my max draw weight and only draw to that weight until tillering is complete.
That one quote is probably the best I've heard about tillering so far. To the point and precise.
Very good Pat....
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Bryce
your explanation gives me some pointers that I have not heard before. Thanks :)
But on the other hand,
Try to nail the thickness taper on the bandsaw.
Floor tiller about 4" of tip movement
Brace, make the brace profile as perfect as possible.
These parts of the process are more like goals to me than instructions, but of course you mentioned that.....
(takes awhile to get a good eye for that)
so opened this thread with the intention of learning more about how that is done.
Perhaps I can ask my question another way.
If I have my bow bending about 6" on the tiller tree, what should I be seeing and feeling so that I do not have to overwork it inch by inch to final draw length?
willie
I guess I can get a little more detailed.
Now Iam by no means claiming to be good at tillering. That is just my process.
I brace it as soon as possible at 4"(<--brace hieght)
Once that is done you will clearly see any flaws in the tiller.
Then I'll tiller out to about 12"-18" of draw. Then fully brace the bow which is usually 6" or so. Now at the point I've got a really nice brace, not pulling over my desired weight (+5lbs of course) and if the brace profile needs to be tweaked this is the time. No more rasp.
And tillering just becomes more about long even strokes of wood removal, along with excercising and checking weight till the bow reaches full draw. Then I will break the bow in by shooting 25 arrows. Check tiller, shoot 25, check tiller until live shot it around 100 times and if I'm satisfied I'll put a finish on it. If not... I'll throw it in the corner.
Sometimes making small heat treating corrections come into play but I will not go into that.
More or less like this
http://www.primitivearcher.com/smf/index.php/topic,3895.15.html
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Byrce
thanks for taking a little more of your time to pass along your experience. The willingness of the members of this forum to share with others is rare in todays world.
willie
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No problem at all :D you will soon find your groove when it comes to tillering. There is alot of good experienced gentleman on this forum that are more than willing to point yah in the right direction.
Get that sticking bending ;D
-Pinecone
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Very good instructions Bryce, :) that's about the way I do it,with a few little exceptions. :) :) if you will follow them instructions willie you will be well on your way. :)
Pappy
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Bryce, that is some of the most comprehensive instruction that I have read about tillering, thank you for posting. Great link for the no set tillering method too. Still being an relitivley new to this, this was very helpful. It made some of the (you'll get it) ideal,a little more like I get it. :o