Author Topic: Rough limb thickness  (Read 5050 times)

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Don Case

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Rough limb thickness
« on: November 30, 2013, 12:38:24 pm »
Here I go with another "rule of thumb" question. When you are roughing out a stave to improve drying time what are the smallest dimensions can you use for the limbs and not run the risk of coming in underweight. For me the max weight would be under 50#(probably quite a bit under, I'm not a strong man). I'm thinking 2" wide and 3/4" thick. I realize it's hard to generalize but I'm trying to build a stock of staves before I have any experience in bow making. The thinner the staves are the faster they dry and the easier they are to strap/clamp to a 2x4 to correct any flaws.
Thanks
Don

Offline Badger

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Re: Rough limb thickness
« Reply #1 on: November 30, 2013, 12:41:34 pm »
  Don, I always rough out my staves when they are pretty wet. I don't go by thickness as much as I do just floor tillering for a slight bend when I push them to the floor. A 72" elb might be close to 3/4 thick and a short recurve might be less than 3/8 thick. Most of your 50# middle 60's length flat long bows are around 1/2" but I honestly never measure them.

Offline NonBacked

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Re: Rough limb thickness
« Reply #2 on: November 30, 2013, 06:04:40 pm »
See if this chart makes any sense. I've been using these rough-out dimensions for a couple of years on hunting weight (50# to 60#) bows from 62" to 68". I’ve made standard, ultimate, pyramid, and molly bows with no drying or draw weight problems. These dimensions also provide a pretty good start for floor tiller. The other dimensions are purely extrapolations based on limb length and limb profile. Hopefully, others will comment on their experiences, and I can update my spreadsheet with “real” data.   


Offline Badger

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Re: Rough limb thickness
« Reply #3 on: November 30, 2013, 07:09:52 pm »
    Those look pretty good, are you using them on moderately crowned staves as well or boards?.

Offline bow101

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Re: Rough limb thickness
« Reply #4 on: November 30, 2013, 07:27:20 pm »
That chart is a good reference.  I find that for most board/laminate bows that the over all thickness to be around 7/16" and the fades around 3/4" anything over  7/16" I found was pulling like over 55#.  Like to keep mine around 44-46#
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Offline NonBacked

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Re: Rough limb thickness
« Reply #5 on: December 01, 2013, 12:31:11 am »
Don – I would encourage you to get maybe 3 or 4 staves, rough cut them to size, let them dry, and start making bows. You’ll get a quick education about all the stuff discussed on this site - moisture content, mass weight, limb profiles, tillering, etc. Then start building your stave inventory. It would be a shame to cut down two or three dozen staves and find out they’re too thin, too narrow, or too short for the bows you’re wanting to build.

Steve – The dimensions in this chart are primarily based on staves from 6” to 14” trees. I’ve used the same dimensions for drying saplings too. The jury is still out on that one because several splits reflexed and/or twisted way too far while drying. The ones that were usable for bows had very good floor tiller profiles.

I haven’t made a lot of board bows with handles – about 12, and only a third of them survived. Big lesson for me: You can’t make a Bois d’Arc bow out of a red oak board!  However, I have two pyramid flat bows (67” ntn) and two typical flat bows (66” ntn) made from 3/4” boards that have final tapers that match those in the chart, 3/16” and 1/4” respectively. All four are hunting weight bows. 

Don Case

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Re: Rough limb thickness
« Reply #6 on: December 01, 2013, 01:26:28 am »
It would be a shame to cut down two or three dozen staves and find out they’re too thin, too narrow, or too short for the bows you’re wanting to build.

That's why I asked the question. :)

Offline steve b.

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Re: Rough limb thickness
« Reply #7 on: December 01, 2013, 03:29:16 am »
Don, I layout all bows on all woods at 2" wide and cut just outside those lines.  Then I cut the thickness to about 3/4"to 1" and a huge handle area since I don't know at that time whether it will be stiff or bendy.

Offline PEARL DRUMS

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Re: Rough limb thickness
« Reply #8 on: December 01, 2013, 09:14:34 am »
Pretty handy numbers NonBacked. Green or dry, those are good starters off a saw, if a guy uses one. The rest is easily done with rasps.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Badger

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Re: Rough limb thickness
« Reply #9 on: December 01, 2013, 10:19:53 am »
  Thats a good chart, on wood bows I normally think of thickness as just out of the fades. I like how you showed the tapers.

Don Case

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Re: Rough limb thickness
« Reply #10 on: December 01, 2013, 01:41:58 pm »
Thanks guys. It sounds like I will be safe with 2 x 3/4". With the OS I would have to glue two together. :)  A few of the bows I build will be for my granddaughter(15) so if I end up with a couple of light ones it's no problem. Now I have to wait for Santa to bring me a farriers rasp.(If he doesn't I will head to the shop on Boxing Day ;) )
Don

Offline Pappy

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Re: Rough limb thickness
« Reply #11 on: December 02, 2013, 10:04:54 am »
Most of my bows are in the high 40s to low/mid 50s 62 to 66 long [Osage/Hickory]
I rought them 1 3/4 down to  mid limb then to about 3/4 at the tips,and about 5/8 thick,always have plenty of wood to work with and can make about any design I am interested in with that.  :) If I am using different wood I am not use to I do like Badger.  :)
 Pappy
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