|The "Evolution 1"|
The "Evolution 1" is a finger powered center crank mechanism designed to teach the basics of how the semi-linear motion of the connecting rod is converted into the rotary motion of the flywheel. This is accomplished by finger power applied to the pivot arm (above left) which connects to the center crank via the brass connecting rod. The concepts of timing, reversing, and single vs. dual applications of power per revolution can not only be seen but felt in this rugged design.
From a machining standpoint, construction is straightforward and simple since the crankshaft is "built-up" rather than being machined from a solid blank. The concept of a "split" connecting rod (on the crank end) is used as can be seen in the photo (above right). This differs from the "Simplex" and "Mill Engine" but is necessitated due to the center crank design. Brass bushings are used for the crankshaft and brass or steel bushings are used for the pivot arm shaft for easy replacement should they ever wear. Though the basic design is plain, with 3/8" aluminum used for the base and side frames, there is ample opportunity for adding your own creative touches using decorative cutouts in the side frames, a damascened finish on exposed surfaces, or a paint scheme to suit your own tastes.
Overall dimensions are apprx. 2 3/4" W x 2 7/8" H x 4 3/8" L
The plan set consists of 5 pages of drawings and 2 pages of construction notes for $7.50 (US postage paid). Please see the general info. page and order page for more detailed information on plan sets.