Elementary mechanical drawing, for school and shop (1886)
Aborn, Frank, 1845- [from old catalog] · Cincinnati, New York, Van Antwerp, Bragg & co · leaf 99
a (Fig.122). Since the awfrom ac. As thisfrom ar to pitch is li in., in. helix advances in making one revolution, it will advance -^of that distance in making-^ of one revolution. This heinsf a riffht-hand heing ahelix, it will pass from leftto right. Begin at a and a,and divide the plan, abc,… … Fig. 122. Join these points 98 MECHANICAL DRAWING. of intersection by a curved line. This line will beone pitch (1J in.) of the required helix. The re-maining portion (1 in.) may be described in thesame way. Note.—To describe a left-hand helix, the line would passfrom right to left instead of from…
Mechanical drawing
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