Author Topic: Next bow  (Read 2442 times)

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Don Case

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Next bow
« on: May 29, 2014, 03:11:16 pm »
For my next bow I thought I would try the thin tips/Eiffel Tower thing. Is there a relationship between limb width and thickness that will stop the outer limbs from bending sideways. Something like "never go beyond square", that kind of thing? If the stave has some character, does that affect how narrow the limbs can be?
Thanks
Don

Offline Pat B

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Re: Next bow
« Reply #1 on: May 29, 2014, 03:21:16 pm »
Don, I usually keep tips about 1/2" thick so they can be narrowed to 3/8" or less. I don't think character would affect tip width unless there was a knot right at the tip.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline huisme

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Re: Next bow
« Reply #2 on: May 29, 2014, 03:30:45 pm »
I thin to ~1/2" thickness, establish the width I like, tiller the bow, then slowly reduce thickness until there's just a hair of bend at full draw. I left the last lever with a lot of wiggle a little thick, but that might have been a mistake ???
50#@26"
Black locust. Black locust everywhere.
Mollegabets all day long.
Might as well make them short, save some wood to keep warm.

Don Case

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Re: Next bow
« Reply #3 on: May 29, 2014, 04:06:22 pm »
Thanks guys. I've only done a couple of bows but I have noticed that they tend to twist slightly towards the inside of a sideways curve, if you follow me. I didn't think that twisting a narrow tip would be a good thing. Because of that I thought I should be a little cautious. Most of the bends are towards the center on this one so it shouldn't be a big deal.

Offline Pat B

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Re: Next bow
« Reply #4 on: May 29, 2014, 07:21:26 pm »
Don, think of a 2x4...flat it will give a little. On edge it is quite rigid. Narrow thick tips have less physical weight than a thin wide tip and bend less. I usually leave tips and handle area bulky at least until first brace so I can see how the string track but usually don't do a final shaping until the bow is near full tiller.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Don Case

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Re: Next bow
« Reply #5 on: May 29, 2014, 07:40:54 pm »
Don, think of a 2x4...flat it will give a little. On edge it is quite rigid. Narrow thick tips have less physical weight than a thin wide tip and bend less

What I'm concerned about is loading the 2x4 on edge to its max and then having it flip over on its side :o :o

Offline huisme

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Re: Next bow
« Reply #6 on: May 29, 2014, 07:57:53 pm »
Quote
What I'm concerned about is loading the 2x4 on edge to its max and then having it flip over on its side :o :o

It hasn't happened to me yet, even fighting propeller twist or pulling slightly out of string alignment.
50#@26"
Black locust. Black locust everywhere.
Mollegabets all day long.
Might as well make them short, save some wood to keep warm.

Offline Pat B

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Re: Next bow
« Reply #7 on: May 29, 2014, 08:06:58 pm »
Keep everything straight and taper the tip width slightly to reduce the chance of lateral movement...and wait until the end of the process to shape the tips.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Josh B

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Re: Next bow
« Reply #8 on: May 30, 2014, 01:16:29 pm »
Don, your concern is a legitimate worry.   The wood will always bend towards the path of least resistance.  If everything is straight skinny levers will pull straight back like you want.  It doesn't take much misalignment to make the levers bend sideways easier than the working limbs will bend straight back as you draw.  Make sure the string tracks straight down the levers and it should be fine.  Also make sure you pay close attention to your side to side thickness on the working part of the limb.  If it torques to one side or the other as you draw, it will throw everything out of alignment.  I hope that helps.  Josh

Offline Badger

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Re: Next bow
« Reply #9 on: May 30, 2014, 01:24:28 pm »
  Don, on real long bows the string tension is higher at brace and tends to twist more easily. I would narrow them gradually  and be super sensitive to any sign of torquing. I have seen bows posted here that look to be about 1/2 wide 12" from the tips, they need to be super straight.

Don Case

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Re: Next bow
« Reply #10 on: May 30, 2014, 02:08:55 pm »
I'm no where near that extreme. At the moment it's about 3/8" at the tip but it widens to 7/8" a foot from the tip. It seems stable.
Thanks