Red Oak Board Bow Layout.

How to make a Bow, a String or a Set of Arrows. Making equipment & tools for use in Traditional Archery and Bowhunting.

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Nezwin
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Re: Red Oak Board Bow Layout.

#31 Post by Nezwin » Sun Nov 22, 2015 2:22 pm

I don't know about anyone else, but all those lines & arcs are a bit distracting to the eye. It would be good to get an untouched copy of the picture, too.

Looks like the tillering is going okay, though. What is your target weight? I make a fair few light bows and for kids I usually aim for around 20#@28". For casual shooters or women I don't usually go much over 30#@28". These are all, obviously, target bows and no good for hunting.

indie
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Re: Red Oak Board Bow Layout.

#32 Post by indie » Tue Nov 24, 2015 5:52 am

Thanks Nez. Original photo of bow attached. I'm looking at around 20# at 20" at this point but suspect I'll have to play with that weight a bit depending on how they go.

The thing that has me most concerned at this point is the twist and how to deal with it.
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Nezwin
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Re: Red Oak Board Bow Layout.

#33 Post by Nezwin » Tue Nov 24, 2015 3:00 pm

indie wrote:...the right limb is twisting clockwise when viewed from the tip. Bugger. I will check to see the limb thickness is even across the entire width. Twist seems to develop early in the limb so maybe needs some light scraping on the front side (viewed from the front as per pic) or left side when viewed from tip to get that side of the limb bending as per the rear side.
A little limb twist isn't going to throw the string or cause any huge problems - twist on a recurve is more of an issue but not always a 'do or die' problem. I'd also remind you of your own comment...
indie wrote:... this is more about the learning process...
If this is one of your first bows, it's probably best to get it throwing arrows then to worry too much about performance. Personally, I'm not all that fussed about performance at all. Performance doesn't always relate to a bow being nice to shoot (although, yes, there is a degree of correlation). From the tillering jobs on some overseas bow making forums, people get away with some pretty shocking full-draw profiles and still have working bows. It's a distinction of this forum that excellence is always targeted (if you excuse the pun).

If the twist is getting too much, check the depth of the limb edge-to-edge. You should be able to see where the twist is located or isolated when the bow is at low brace or short draw. Making marks at 1" intervals and checking all your measurements are even throughout can sometimes help. Scrapers, drawknives & spokeshaves tend to work best on corners and edges, so it could be that you've taken more off one edge than another. This is particularly the case on flat bellied bows, in my experience, where the tool doesn't have as much purchase in cutting the material. Almost all of my bows are flat bellied and I tiller with 40 to 80 grit sandpaper (by hand) or 120 grit in long, light, smooth strokes on the belt sander. Don't use the beltsander though, I probably shouldn't and it's probably a bad idea...

indie
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Re: Red Oak Board Bow Layout.

#34 Post by indie » Sun Dec 27, 2015 4:02 pm

Hey guys. Trying to get back to this after Christmas etc. Received my string material and have just made up a jig. The small bow is 48" ntn and wondering what length to make the string. I'm guessing the brace height would be around 4" from the back and the string 45" long. If someone can let me know what they think please.

Cheers, Indie.

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greybeard
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Re: Red Oak Board Bow Layout.

#35 Post by greybeard » Sun Dec 27, 2015 4:58 pm

indie wrote:......I'm guessing the brace height would be around 4" from the back and the string 45" long......
Four inches from the belly may be as starting point, four and a half inches at brace may also be suitable.

You will need to experiment with brace height as all bows are slightly different.

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yeoman
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Re: Red Oak Board Bow Layout.

#36 Post by yeoman » Sun Dec 27, 2015 6:13 pm

For such a shot bow, four inches shorter is an enormous proportion. This might give a six or more inch brace height.

When I'm tillering, I progressively shorten the tiller string until I get the bow to brace height.

Then I can use the tiller string as a template for the exact length I need to make the final string to get the desired brace height.
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indie
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Re: Red Oak Board Bow Layout.

#37 Post by indie » Sun Dec 27, 2015 7:11 pm

Thanks guys. I was thinking 3" shorter was maybe a bit too short, just means I need to add another nail to the jig. ;) Simple enough. I just measured my tillering string and it's at 47" which gives only about 1 1/2" brace. So 46" seems about right. Might err a touch on the long side. For the brace height I'll just play with it and see what works.

I've still got a fair bit of limb twist going on. I'll do my best to ignore it and just see if I can get a shooter. I think this thing could still pack a fair punch. Love the feel of it, super light and very manageable at this short length. No doubt a bit too short for me but I think after I get this one and the longer 66" NTN done I may play with a shorter version.

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