Fig. 146

Tools Required

Compass, thumb-gauge, jack plane, trying plane, and tenon saw.

The illustration here given shows a regular hexagonal prism, but this particular form need not necessarily be adhered to.

Take a piece of yellow deal of about 1 1/2 in. square in section, and a little more than a foot long, and plane it up true to the dimensions of the rectangle which encloses the figure in the drawing, with a jack and trying plane. Cut off one end square with the faces, and on it draw the chosen polygon in the manner shown in fig. 146. With thumb-gauge and pencil draw lines from the angles made by the side of this polygon, completely down the length of the wood, and join the points made by the extremity of these lines at the other end of the wood, and a second polygon, similar to the first, will be obtained. The portions to be removed by edge planing will now be indicated. Fig. 147 shows the manner in which this is done. Two small pieces of wood are screwed up in the vice and act as stops to the wood to be planed. This is not screwed in the vice, but fixed in between the two stops.

Fig. 146.

The fingers of the left hand cannot in this exercise rest on the wood below the face, but are doubled up for safety, yet the position of the hand is still useful in guiding the plane. The manner of holding the plane in surface planing, with the fingers gripping the other side of the tool, will not be found advisable now, as the action of the arm in the forward stroke is not so well calculated to send the plane in a straight line. In the present case, moreover, the surface to be planed is very small, and sufficient downward pressure can be given with the thumb alone.

Fig. 147.

If an octagonal prism is made the angles may be removed successively and the form gradually made rounder, till it can be finished into a ruler with a file, as in fig. 148. As the file is steadily pushed across the wood, the model itself is turned with the other hand against the file, so that the surface is acted on by turning both the wood and file simultaneously.

Fig. 148.