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Main Boards => The Bowyer's Bench => Topic started by: Pat B on February 14, 2009, 12:30:00 PM
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This is how I determine limb thickness on selfbows. I use my hand and a pencil as a gauge to mark down the entire limb from tip to tip and on both sides. This will help keep your limb thickness even from side to side. After I have found the back ring and cleaned it from one end to the other I will put a pencil mark at about 3/4" to start with and usually remove the excess wood with a band saw starting on the edges with a beveled cut down both sides then reduce the crown down the middle...then check floor tiller.
Next I go a bit closer to the back(1/2" to 5/8") with the same method but begin reducing to that line with a farriers rasp using the same method or removing the corners first then the crown...and check the floor tiller. I continue this until it floor tillers to about 4" to 6".
Now it is time to long string and check both limbs together. From this point on it is all done by the bend of the limbs.
You will notice that the pencil line mimics the back of the bow following any undulations
(http://i5.photobucket.com/albums/y199/PatBNC/bowbuildingtools002.jpg)
(http://i5.photobucket.com/albums/y199/PatBNC/bowbuildingtools001.jpg)
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Good stuff Pat, thanks. I'm hoping to find time to start on an osage stave in the corner.
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Pat, nice insight into some of the way you work. I have been thinking of making a gizmo that would do the same thing, similar to the center marking gizmo you have on your other thread. If the stop was slidding then it could be adjusted to meet the depth you want. Little more consistent than locking fingers and no surprise splinters.
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You really don't have to be too precise with this. It is only a guideline to get the limbs about the same thickness and following the undulations. When I get beyond floor tiller stage I use my thumb and fingers to "feel" the thickness and where it is thicker or thinner. This method is quite accurate. Once the limb begins bending well, Eric's gizmo is the ticket. The actual thickness doesn't matter as much as an even bend.
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I use a compass for marking limb thickness. Set the pencil tip a little back from the point and the point will ride down the stave's back while the pencil marks the edge,folowing the back perfectly.
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That's similar to how I do it Pat. Thanks for sharing.