Author Topic: draw length  (Read 6022 times)

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Offline Hopefullbowyer

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draw length
« on: July 10, 2009, 07:07:53 am »
Just stared in bow making.  Had a cherry limb not good bow wood; to many knots curvey grain.  Broke while working the bend.  Sons brought two 8ft walnut limbs home about 3in taper to 2in.  I cut one limd in half diaganoly start working on one piece.  It is 59.5 "  long and 1.75 approxamately wide at widest point. being a short bow was not sure how much draw length I should expect.  Have been reading bowyers bible, but have not really seen anything relating bow length to max draw length.  This is my second attempt at making a bow so try to keep help in simple terms.  Will try to include pictures later I am at work, and new to message boards.

I think I managed to get pictures.

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« Last Edit: July 11, 2009, 01:49:50 pm by Hopefullbowyer »

Offline Ohio John

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Re: draw length
« Reply #1 on: July 10, 2009, 08:24:04 am »
I'm still a novice myself but so far a good rule of thumb seems to be that bow length should be at least double the maximum draw. I'm not saying that with skill you can't produce bows of shorter lengths and longer draws, just that it is an easy place to start. Good luck with all your bowmaking.  I have 5 successes and 6 broken ones so far (usually because I was trying to cut corners).. Take your time bowyering is one of the best relaxing and focusing activities I've found.
I like to throw rocks at em..... just like my grandfather's, grandfathers, grandfather's, grandfather's, grandfather did

Offline islandpiper

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Re: draw length
« Reply #2 on: July 10, 2009, 08:24:44 am »
tsk, tsk......another life pi$$ed away making shavings......how sad.   Join the club, brother.  

I'll be the first to tell you.......go slow, don't get in a hurry, pay attention to the wood. Read about a million old posts here, look at the build alongs and pics.  ask lots of questions.  

Other, lots smarter guys than me will advise you on the physics of overall length and draw length.  

have fun, make lots of bows, piper

Offline George Tsoukalas

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Re: draw length
« Reply #3 on: July 10, 2009, 09:11:39 am »
let's see of we can help you. What's your draw length? Board or log? There's info on my site. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/
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If you ain't breakin' you ain't makin!

Offline DustinDees

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Re: draw length
« Reply #4 on: July 10, 2009, 02:40:52 pm »
i have to agree with islandpiper on this one. i have yet to get tillering down well enough to make shorties. there are many on here more experienced than I that can help you with that. I have not determined when the addiction started, with the first shavings or once i got tiller out to full draw length.... i think as soon as you send the first arrow from a bow you made yourself, your doomed to make bows forever! >:D welcome to the addiction.

Dustin D
“Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for.” – Epicurus
Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. That's Relativit

Offline Hopefullbowyer

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Re: draw length
« Reply #5 on: July 14, 2009, 06:07:39 pm »
o. k. working through tillering was able to get 27 or 28 inches of flex.  not sure because I haven't built a tiller tree yet. After sanding to finish bow I noticed some chrysal and a small crack.  The crack is about 11 inches up from center of handle looks about 8/64 deep runs diagonally 3/4 of in.  The bow width at point of crack is about 1 1/4 in. depth is 1/2 inch.  I probably need to take more off of tips to prevent more chrysals.  My question is would this be worth scraping out to save the bow or should I enjoy shooting until it breaks.  Draw weight is of little concern to me as long as it will shoot arrows 10 to 15 feet.  Right now it is around 25 to 35lbs: no spring scale estimating by feel of two bows with known pull weight.  original intention was to make a bow for my kids.  they can only pull about 15 to 20 lbs.am trying to include pictures.

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Offline Ohio John

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Re: draw length
« Reply #6 on: July 14, 2009, 08:57:44 pm »
I just finished a trio of kids bows
(I put them in storage as I am moving but will post pics once I'm settled and get pice of them with my three nephews) .
 I find it strange that you would  draw a kids bow 28 inches. Most kids bows only need to pull 20-24 inches. Overdraw is the main bow wrecker around my bench. I've wrecked a whole stack of nice osage bows by not being gentle and forcing them back beyond what they were ready for.
I like to throw rocks at em..... just like my grandfather's, grandfathers, grandfather's, grandfather's, grandfather did

Offline Hopefullbowyer

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Re: draw length
« Reply #7 on: July 14, 2009, 09:24:29 pm »
I was not able to find any advice in my books for a proper draw length for a bow 59 1/2 inches ntn, and i wanted to be able to shoot as well since I own no bows.

radius

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Re: draw length
« Reply #8 on: July 14, 2009, 11:06:18 pm »
here's the deal, as i understand it...

bow length = 2 x draw length (one each limb) plus handle and fades.

that's a starting guideline.  For better woods, you can reduce it somewhat.  I think Nomadic Pirate said he made a 58" yew bow that drew 75# at 28". 

that bow length = 2 x draw length plus a mere 2 inches.  He really made those limbs work.

Offline Hopefullbowyer

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Re: draw length
« Reply #9 on: July 15, 2009, 07:55:30 am »
radius thanks for the info on draw length.  By that formula I have definately over drawn this bow.  Still wondering if i can save this bow by filing out the 8/64 depth the crack appears to be.  Should I maybe add a little fiberglass backing to improve saftey, since draw weight is not of major concern.  I know fiberglass might be a bad word but it is inexpensive and easy to get a hold of for a newbie.

Offline GregB

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Re: draw length
« Reply #10 on: July 15, 2009, 08:07:25 am »
Hopefullbowyer, I'd advise you to make a tillering tree as soon as you can. As you probably know it allows you to watch the limbs flexing, watch the draw-weight, and drawlength all at the same time. You can set out wanting a certain draw weight at a particular draw length and the tillering tree allows you to accomplish that. As has been said many times here...except for maybe giving a little safety cushion beyond the draw length you're after, you shouldn't draw the bow at any time beyond the intended draw weight. That is just unnecessarily stressing the bow...difficult to prevent without a tillering tree.  I know you've already mentioned you planned to make one, I think that's a good idea! ;) Good luck!
Greg

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radius

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Re: draw length
« Reply #11 on: July 15, 2009, 09:19:26 am »
8/64!

dude, just say 1/8th!

Offline George Tsoukalas

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Re: draw length
« Reply #12 on: July 15, 2009, 09:48:13 am »
Double your draw and add 20-25% depending on the wood and your experience level and the wood so about 65 inches ntn for a 27 in. draw. That assumes and 8 inch non bending handle. There's info on my site and buildalongs. Already posted it. Jawge
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If you ain't breakin' you ain't makin!

Offline Hopefullbowyer

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Re: draw length
« Reply #13 on: July 18, 2009, 09:58:00 pm »
o.k. I tend to find it easier to just say the number when using a machinist scale than to reduce the fraction.  Sorry.  I have decided to go ahead and remove the material till the crack is no longer present. so I removed a little more than 1/8inch. the draw weight has been greatly reduced.  My kids should be able to pull with no problem.  I am ready to due some final tillering.  I have taken pictures at a 24 1/2 inch draw.I think it looks like i have some bad hinges in the area just past the fade.  Anyone have some thoughts.  Once i have the final tiller I am going to probably put somekind of backing on to raisee the pull weight a little my youngst 8 can easily pull now.

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Offline tombo

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Re: draw length
« Reply #14 on: July 18, 2009, 11:24:49 pm »
Darn good for a first bow! You need to take a bit more off near the hand hold. You're hinging about 4-5 inches out from your hand on both ends , you'll get more life out of that thing making it bend more smoothly. Be careful or you'll get to like doing this!
Tom