Bob Smalser
06-16-2004, 8:30 PM
All the descriptions I’ve ever read on these needed a good picture, so I thought since I made another one today, I’d take a pic.
These mark square or rectangular stock into 8 sides, dividing each face of the stock into three equal sections…the first step in planing a cylinder from a square. The nice feature of this design, is that it accommodates tapered stock, so is perfect for spars and the oars I am making here.
http://pic3.picturetrail.com/VOL12/1104763/4518261/56920059.jpg
Cut a block the diameter of the largest cross section of your finished spar or loom…draw a circle in it so the circle intersects the edges. Then use a 45 degree square to make an octagon of it.
Another block an inch wide and a couple inches longer than the first block is laid atop…both the edges of the circle and the corners of the octagon are transferred to the second block, holes drilled for nails and pencil…and you have your gage.
Offset the holes for the guide nails to insure they are outboard of the circle.
http://pic3.picturetrail.com/VOL12/1104763/4518261/56920050.jpg
Then merely keep the guide nails in contact with the edges of your stock, and you can mark any tapered piece into an octagon for planing…
http://pic3.picturetrail.com/VOL12/1104763/4518261/56920042.jpg
..and all that remains is to drawknife, plane and spokeshave those corners to the lines. (On oars, I rough out the handles, first so the drawknife doesn’t take a chunk out of them as I work rapidly to the lines.)
These mark square or rectangular stock into 8 sides, dividing each face of the stock into three equal sections…the first step in planing a cylinder from a square. The nice feature of this design, is that it accommodates tapered stock, so is perfect for spars and the oars I am making here.
http://pic3.picturetrail.com/VOL12/1104763/4518261/56920059.jpg
Cut a block the diameter of the largest cross section of your finished spar or loom…draw a circle in it so the circle intersects the edges. Then use a 45 degree square to make an octagon of it.
Another block an inch wide and a couple inches longer than the first block is laid atop…both the edges of the circle and the corners of the octagon are transferred to the second block, holes drilled for nails and pencil…and you have your gage.
Offset the holes for the guide nails to insure they are outboard of the circle.
http://pic3.picturetrail.com/VOL12/1104763/4518261/56920050.jpg
Then merely keep the guide nails in contact with the edges of your stock, and you can mark any tapered piece into an octagon for planing…
http://pic3.picturetrail.com/VOL12/1104763/4518261/56920042.jpg
..and all that remains is to drawknife, plane and spokeshave those corners to the lines. (On oars, I rough out the handles, first so the drawknife doesn’t take a chunk out of them as I work rapidly to the lines.)