Primitive Archer
Main Discussion Area => Bows => Topic started by: Wooden Spring on January 21, 2013, 04:24:19 pm
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What I've got so far... I've got a hickory flatbow all roughed out and backed with linen. It's 69" NTN, 11/16" thick at the tapers, then tapers down to 3/8" at the nocks, it's 1-1/2" wide for 12", then tapers down to 3/8" at the nocks. It's got a 4" long handle, and 1-1/2" long fades...
Here's my problem... I've only tillered it to just a couple inches beyond brace height, (shown in the picture with the long tillering string) and it pulls 60 pounds to get it that far. Now, being a newbie to the whole process, what's the best way to bring the weight DOWN? Do I take wood off of the sides? Do I take wood off of the thickness? Or some combination of both? (I want the final weight at 28" draw to be around 45-50#)
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remove wood from the thickness, continue to thin it until you have lightened it. Just remove wood evenly until you can pull it close to your draw length at draw weight on long string, then when you brace it you can fix any errors, but try to do that as best you can while removing wood. hopefully you wont have to do much correcting of tiller when you brace it.
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You need to low brace the bow 3-4" now and then have another look. When you start pulling in and down it changes everything. Your fades are VERY short and abrupt, hope they dont come back and bite you later.
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also you shouldn't draw it past your target weight or you will get some set.
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also you shouldn't draw it past your target weight or you will get some set.
That seems to be a very broad term. "target weight" Why because what if you suddenly change your mind and want 60# instead of 50#..... So now you pull a little further not knowing that you have actually pulled to much say to 58# and the bow has taken on a lot of set or more set than what was anticipated..
This is where most Newbies get into trouble. Not so much the draw weight, because I never check untill I'm 96% done. It's more of the bending factor.
Oh it's bending OK but extremely stiff like it's .........Stacking....?
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also you shouldn't draw it past your target weight or you will get some set.
Well rats... Another one for the burn barrel. That's it. I give up. I've been trying to get a shootable bow now for over 6 months. I have been a woodworker all my life, and I have never had something cause as much grief as this... All those people who made a shootable bow their first try must have had some magical combination of luck and opportunity...
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Your bow is far from junk. Shorten the string up and brcae it at 3-4". Pulling it past your target weight isnt too big of deal providing the tiller is close. Hardly anything any of us would notice at the end when we are shooting. I dont even scale my bows until Im braced up at 4-5", then worry about settling it in where I want it.
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For the record I have years and years of woodworking experience as well, none of it translates to bowyering. You may have a leg up in getting a good finish on a bow though.
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also you shouldn't draw it past your target weight or you will get some set.
Well rats... Another one for the burn barrel. That's it. I give up. I've been trying to get a shootable bow now for over 6 months. I have been a woodworker all my life, and I have never had something cause as much grief as this... All those people who made a shootable bow their first try must have had some magical combination of luck and opportunity...
Pull yourself together man and get a grip!
You are 80% there!
Get a taut string on it and decide on your target weight.
Pull it back to that weight and look at the curve of it.
If the tips are coming back about 7" and the curve is reasonable, get it to a low brace height (say 4-5") The draw weigh is always less with a shorter string. (Due to the geometry)
You are now at the very point where you must SLOW DOWN !
Don't start getting frustrated and taking off tons of wood. Enjoy slowly taking off small even amounts of wood so each time you pull it back it comes a little further... a bit like courtin' ;D >:D O:) ::)
If you are really stressed out, have a break, make a bow out of a scrap of grren wood or have cup of tea and a bit of toast.
Come on old chap, stiff upper lip... we're not going to let a silly bit of wood wood beat us now are we ;)
A lot of it is patience perseverence and confidence. I still get a crisis of confidence now and then, and as I wind it back on the tiller I'm saying 'BANG' to myself so it won't be a shock if it explodes. Then it's a huge flood of relief when it makes it to draw weight.
Del
BTW Tiller is looking good at the moment, get it on a short string pulling back to 50# and post another pic.
Get a grip!
If I have to come over there... there'll be trouble ;)
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First: DON'T DRAW IT PASS YOUR TARGET WEIGHT!
Second: If you're at 11/16 at the fade NOW, you should have plenty of wood left to remove to gradually, taper out pass the fades by an inch. So, you shouldn't have a problem of the bow hinging out of the handle/fade area. The key is a GRADUAL taper from the handle to an inch past the fades. Don't touch this area for a bit. You can alway come back to this spot if you see it is too stiff.
Third shorten your long string so it's so tight against the belly that you have to force the bow into the tillering tree
My method: scrape the bow correcting the tiller as you go until the tips are bending about 6 inches. Then go to a low brace of 2 to 3 inches. DON'T PULL THE BOW PASSS YOUR TARGET WEIGHT. When the tips are bending about 8 inches go to full brace. Keep tillering until you reach your target draw length just DON'T PULL THE BOW PASSS YOUR TARGET WEIGHT.
Your tiller looks pretty good. I think that hickory with make a bow still. Keep at it.
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Sorry, I can't help writing some more as I'm determined to maximise your chance of making a bow.
To answer your basic question, you will have to remove wood off the belly to bring the weight down.
By this stage you should be using a fine rasp, b'stard file and scrapers.
Ok you are a woodworker, but this is a different discipline as you are asking the wood to do something entirely different, you don't want sharp crisp edges anymore.
Keep checking the back of the bow for any signs of lifting grain and round of the edges to about the curve of a 6" nail or even softer.
Take the advice offered about being carefull at the fades (it's easy to create an accidental thin point there) and if you take off an even thickness along the the whole belly it will automatically have more effect in the outer 2/3 (which is what has been suggested). That is because say 0.01" of an inch off at the tip is a greater % of the total thickness than 0.01" at the fade.
Take it slow and steady, after each go with the rasp/file etc exercise the bow by flexing it a dozen times or so and check how it looks. Always do it, never do a bit and then do some more without exercising and getting it back on the tiller.
You should get thoroughly sick of putting the string on and getting it up on that tiller! Also always put it up the same way round so you don't work on the wrong limb. (I always have top limb to the right)
Mark any bits that don't seem to be bending enough with a cross hatch pencil mark or squiggle, and any areas that look like they may be bending too much mark with L for 'leave'.
Use you fingers as well as your eyes, run the limb between finger and thumb feeling for dips and high spots. If you want the 'security blanket' of the verniers then check thickness every 6" or 4"...
If you want a bit of safety factor aim for 45# at 26 initially, then shoot it in a bit, spend some time studying it and finally tease it back the last couple of inches.
Sorry if I'm going on a bit, but we all want to see you get there.
Del
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When you take that string on and off again a million times as Dell says its important to check the profile of the bow unstrung. If the bow starts to look different in one area only then that area might be taking too much strain/set.
The fades there need to mellow a little if you can.
You will have a bow yet.
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also you shouldn't draw it past your target weight or you will get some set.
Well rats... Another one for the burn barrel. That's it. I give up. I've been trying to get a shootable bow now for over 6 months. I have been a woodworker all my life, and I have never had something cause as much grief as this... All those people who made a shootable bow their first try must have had some magical combination of luck and opportunity...
I hear ya about the woodworking part all your life. Like the others say don't give up. Like yourself I have done my fair share of woodworking and construction. It was getting me down to, but I have learned from every bow I tried to build.
Like Dell said......"Enjoy slowly taking off small even amounts of wood so each time you pull it back it comes a little further... a bit like courtin'
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First off, get rid of that tillering stick, and make yourself a pulley system with an in line scale. Don't leave your bow statically drawn for more than a few seconds. You need to know where you are with draw weight all the time.
Second, round off the edges on the back of the bow. You should do this BEFORE you start tillering.
Third, move to a short string asap. As soon as you can low brace the bow at 3"-4", do it.
Your tiller looks fine so far. Keep going. There's definitely a bow there if you're patient. Keep removing wood, using scraper and rasp, and watch for hinges.
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Dont give up on it dude! Making bows isn't super easy. your doing a great job on it anyway. low brace it, continue tillering from there and your done. Its really rare that anyone makes a perfet bow the first time. Even if it breaks after shooting it for a bit, it's still a learning experience and makes your next ones that much easier.
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It looks good so far. Just take a deep breath and go slow.
Check and double check.
These guys are all giving you good advice.
I just broke an osage that was almost where I wanted it. All I could do was grab another one and start again.
You'll make it work.
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first off relax, pd and del gave you a lot of good info, a pulley system may be safer, don't know never used one, don't unstring it everytime you scrape on it, I do most of my tillering with a knife and I don't cut the string, and it helps you leave the tips a little stiff, and I have pulled a few bows past weight and my bows come out pretty darn flat so if you went past weight a bit don't sweat it, stay away from the fades about 6" for now, tiller look's good, go slow and easy, when you brace the bow set it in the corner for an hr or two and let her sweat some, Bub
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wow dont go burning that bow, i was only advising from what i have read and been told, i am a noob too i have only built 3 bows, so am far from an expert. the work you have done looks good so stick with it. when you start getting peeved go and have a brew. i go through galllons of tea while making a bow lol. good luck with it. :)
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Wow, lots of good advice, and lots of " First off's ".
Lets simplify this. ALLOT.
Your bend looks perfect between both sides. Most struggle with that. Even folks that have made many. You nailed it first time. Keep the fire away from this stick. You dont make bows with fire. ( Nobody mention heat treating, SIMPLE remember? ) Fire+bow= wasted time.
It is ok when on the long string to pull somewhat past your final draw weight. Because of the angle the string against your tips on a long string, the weight you pull is artificially high. You arent actually pulling what your scale says you are until you get a shorter string on there. It is a tip to string angle/leverage thing.
Now here is where we concentrate on what you need to do.
Your fades from where your handle is blending into your limb is the ONLY problem you are facing right now. You are too close to a sharp angle and sharp angles concentrate stress. Stress concentrated breaks bows. You have plenty of room to fix it though. Just look at the bows in the bow gallery to get an idea of how the limbs should blend into the handle. Nice and smooth transition. Bubby gave good advice on saying stay away 6 inches from them for now. That keeps the fades from bending untill you get them more smooth.
The second and last thing you need to do ( until you get your fades fixed ) is put a shorter string on the bow. You need a string that is 3 to 4 inches shorter than the bow itself. I always set my 4 fingers closed together from the nock of the bow and that is where your string should stop. That gives you about 6 inches of brace height, allowing for string stretch.
Your tiller tree is ok. Its a taste thing. Good arguments either way for it. I personally dont and never have used one.
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Dad was a woodworker and carpenter. I helped him build houses. I grew up with a hammer in my hands. Woodworking became my hobby as an adult. Yet, when I started making bows, I needed 14 tries to get a hunting weight shooter spread over 3 years. Stay the course. You are getting good advice. My site may help too. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/index.html
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OK... here's some visual advice for tillering tree set up:
I screwed a half sheet (4X8) of 3/8" plywood to the wall under a shop light. I screwed a 2X4 with a top shelf in the middle of the plywood, being certain it was level. The shelf is 4" wide (the width of my hand) and 4" deep. The first reference line is 6" below the shelf (that's my final full brace height). I have a single pulley at the bottom, a 12" round handle at the end of the rope, and enough rope to be about 10 - 12' from the tiller tree while working the bow. The scale is in line, and big enough that I can see the draw weight all the time. I put draw length reference marks in inches on the vertical 2X4, up to 32" for warbows.
So, draw to your final desired weight, and look at the draw length. Remove wood, rinse, repeat. I find the stave will usually move about 1/2" in draw length with each scraping session. Keep going, until you reach final draw length and weight, being careful not to pull past final desired draw weight.
If I want to look at the bow while tillering at a static length, I hold the bow at that length and take a picture. I download the picture to my laptop, and then I have all the time in the world to look at tiller without hurting the bow. I usually have my laptop out in the shop while I'm tillering, especially towards the end.
This set up is an evolution over about 3 years. I used to drill a deck screw into the 2X4 at each draw length mark, so I could ststically leave the bow drawn, but no more. I also didn't use an in line scale before... I used to just guess, and then measure final draw weight. No more. This set up has reduced the final set my bows are taking by about half.
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Keep in mind, the draw length reference marks are from the top of the shelf, which would be the BELLY of the bow. I measure my draw length from the BACK of the bow, so when tillering, I subtract the thickness of the bow. Example, the bow shown on the tiller tree is 1" thick. I wanted 28" final draw length. So, I tillered the bow to 27" to compensate for the bow's thickness. For this bow, I wanted 50#@28", so I tillered it to 48#@27". The usual change in draw weight is 2-5# per inch of draw length. It came out to 53#@28"... close enough.
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adb, just wondering if you subtract the thickness of the bow from the measurement on the tree and you want 50# @28" wouldn't you want 50# @ 27"on the tree? seems that if 27 on the tree is really 28 you would want your target weight at the 27" mark, Bub
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adb, just wondering if you subtract the thickness of the bow from the measurement on the tree and you want 50# @28" wouldn't you want 50# @ 27"on the tree? seems that if 27 on the tree is really 28 you would want your target weight at the 27" mark, Bub
Yes, sorry, you're right.