Well-made screw — the key to a successful flight “butterflies”. Pick up the wood, without the ROE and knots. Billet screw vystrugat in the form of a rectangular bar size 160х8х10 mm. In the center of the puncture hole for the axis. Then make a paper template of one of the propeller blades. Aligning the centers of the template and of the bar, move the contours of the blade first on one half of the bar, and then another. Billet astrogate a knife strictly on the contour, do the same with a lateral projection. Holding the billet in his left hand, on the opposite half cut the right corners. When finishing, try to front (top) part of the blade was slightly convex and the lower flat or even slightly concave.
The screw is made smooth with sandpaper. At the same time to balance it: make the same weight of the blades. The screw can be ready to varnish, paint or varnish. Now Linden cut the top and bottom of the boss. They also carefully apply the sandpaper.
Two pine slats size 135X3X3 mm vystrugat plane or a knife. When processing it with emery paper, be careful not to round the edges of the bars, as this will make them less hard.