Primitive Archer
Main Discussion Area => Bows => Topic started by: Tiredtim on October 13, 2013, 08:57:04 pm
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I am having difficulty with tillering. I have build about 6 bows and only 2 shoot. I broke the others. One pulls at 50#'s and the other about 35. I go slow and check it often but seem to miss some thing some where. I like what the one guys says, "If you ain't breaking, you ain't making." I'm breaking but not making. Any suggestions or any one know of a good build along that shows tillering? thanks
This is a hinge I have created. It was looking good. I have no idea where I went wrong.
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Looks to me like you need to get the bow bending out of the fades/right off the handle on both limbs. As far as a hinge maybe on the left limb towards the tip. Looks like too much of a whip tiller. What does the back look like. what is the type of wood, board or stave? need a little more info to justify a good response.
DBar
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You whipped the ends. My guess, you didn't get a short string on it soon enough. If you get it braced early you can see the weaker areas while there is still plenty of wood to remove as you even things out. Once braced it's just a matter of getting the radius right on each limb and getting both limbs to match each other. Then just remove wood stem to stern an even number of times on each limb. Exercise and check the tiller. If this bow was pulling say 40 lbs at 10 inches, you could still get it working. Hope that makes sense. Keep plugin'.
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Dan, it is a board bow. Hard Maple backed with hickory in the middle with sinew on the tips. Bob, it kind of makes sense. I'll read and re-read what you said till it does. But what do you mean by short string? And how high should the brace be when doing this? I'm always afraid of snapping one. Not afraid to try just figure it will be a matter of time. That may be why I don't tiller well. Thanks for the information. Keep it coming!
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I mean bracing the bow at 3 to 4 inches early on. I get mine low braced very early on. I think some guys don't because their tillering method is different than mine, but some guys don't out of fear of breaking it. I have never broken one at that stage low bracing it. It allows me to see and modify the shape of the limbs while there is still lots of wood to remove. If it's right at 3 inches then pull it on the tree another inch and check the tiller. Scape exercise and check it again. When it's good at 4 inches go 5. You'll be way heavy but that's to your advantage as you even things up. Brace it at 5 inches when you have pulled it on the tree to 5 inches. Now just keep things even as you go.
Want to clarify something. I don't brace at 5 inches until I have pulled it on the tree to 7 maybe 8 inches.
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There are buildalongs on my site. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/index.html
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Okay let's put tillering in to the simplest terms possible. All tillering is, is basically removing all stiff spots that's it !
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Sorry... it's not quite that simple.
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Sorry... it's not quite that simple.
Well basically, yes it is that's the simplest way to define it
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I see a lot of beginners do that,you tend to scrape the whole limb and as you scrape from fad to tip it is very easy to get deeper, the limb is tapered so they get whipped tillered,just lighten up as you scrape instead of getting harder,it will help with that problem. :) I have seen folks almost cut the last 8 or 10 inches off the bow they get it so thin. :) that beginning hinge you should be able to work out,just don't pull on it until for get some wood off the center to the fads,I always save most of the fads till close to the last,if you get them bending to much to start if will create a hinge and lots more set. ;) :)
Pappy
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Thanks Pappy! So, I need to work the fades and then the tips on this one, correct? You are right, I was digging deep on the scraper. Should I put it on a short string like Del said? He made sense. How exactly do I get rid of the whip tiller?
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Anywhere your bow is bending too much, leave it alone. Like your tips. Don't touch. Anywhere your bow is not bending enough, remove wood. Like your fades and midlimbs. If you have a hinge, don't touch it where it's bending. Remove wood above and below the hinge until it's gone. This is now your weak limb, match the other limb to it.
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Sorry... it's not quite that simple.
Well basically, yes it is that's the simplest way to define it
What about draw weight, draw length, tiller shape, back profile, tip deflection, and symmetrical limb bend? Do they matter?
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What adb said on removing the hinge,I always put a mark on either side of the part that is bending to much and mark it NO,so I am sure to stay off of that till it comes back in with the rest. :) I also stay off or almost off the last 6 or 8 inches
of the limb until you start getting closer to finish,fads and tips are the easiest to get bending to much early on. Fads because all the stress is their toward the center,it's like bending a stick holding it on each end,it will bend in the middle, and tips because they are usually much narrower. :)
Pappy
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I think a common newbie mistake is handle waaaaay too long. Fades waaaay too long.
Newbies are firghtened of too sharp a fade and all the books say blend it it in gently.
The problem is you end up with the centre third stiff, and then the two ends whip tillered. giving what I call a 'square' tiller 'cos it looks like |_| but up the other way.
Have a trawl through my bowyers diary, there are plenty of pics of bows being tillered at various stages. , but and also some vids.
A good trick is to hold a plate, mug, CD or whatever up in front of you as you look at the bow, it will show where the bend isn't smooth.
I've got an Elm warbow in the early stages on my blog there at the mo', you can see it's not perfect, if you hold up a Cd to the pics you can see where it is stif and where it bends too much... I also explain how I'm going to fix it.
http://bowyersdiary.blogspot.co.uk/2013/10/busy-weekend.html (http://bowyersdiary.blogspot.co.uk/2013/10/busy-weekend.html)
Del
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A good floor tiller will go a long way!get it really close by eye and feel.put the shortest string that you can fit without struggling to much.exersise it on a tillering stick maybe pulling 10" for 20 to 30 times ,hook it on a notch at about 10" ,take a few steps back and assess quickly(maybe take a pic).this all has to be done as quick as possible.mark it with a pencil where to remove wood and where not to.when your happy go to a low brace of 3",exercising well as you go making sure to sight down the limb with every chance you get to see where the wood is beginning to show signs of stress(set).you would see early on in your case that the outer limbs were working to much and starting to deform.study the brace very closely as this will speak volumes as to how even your tiller is.I constantly run my hand up and down the back juring the whole process to feel for splinters.return it to the tillering stick until you are confident to go to brace height.if you don't understand some of the terms I have. Used just ask ,somebody will fill you in(not sure if there is a bow building glossary on here somewhere?) There are many ways to skin a cat and this is just one.
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Sorry... it's not quite that simple.
Well basically, yes it is that's the simplest way to define it
What about draw weight, draw length, tiller shape, back profile, tip deflection, and symmetrical limb bend? Do they matter?
Lol
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(not sure if there is a bow building glossary on here somewhere?)
I found this very handy:
http://www.primitivearcher.com/smf/index.php/topic,978.0.html
Its located in the Archive section.
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(not sure if there is a bow building glossary on here somewhere?)
I found this very handy:
http://www.primitivearcher.com/smf/index.php/topic,978.0.html
Its located in the Archive section.
Very handy. Thanks
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What adb said on removing the hinge,I always put a mark on either side of the part that is bending to much and mark it NO,so I am sure to stay off of that till it comes back in with the rest. :)
I do that too and sometimes I wrap masking tape around a hinge or area that I don't want to touch until you don't see it any more.
DBar
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I've taken y'all's advise and it is working. Del, I'm making the fade not as long. And Pappy, I did just what you said. I wrote "NO" where the hinge or whip tiller was. I may have a bow that pulls less than I want it to but I have learned a great deal. Thanks to every one.
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Better to have a well tillered lighter weight bow, than a poor heavier bow.