These models are from the 1929 #9 Mechanical Wonders set. The model on the right side of the back plate is the Cone Pulleys model, the first model in the wonders section of the manual and the easiest. The model on the left side of the back plate is part of the rectilinear motion model. All of the parts used are from the late 20’s with the exception of modern machine screws. The six shiny metal car trucks are from a mid-1920s Gilbert Meccano set. Special thanks to Joel Perlin for supplying the parts specific to the 1929 #9 set, those being the eccentric, cone pulleys and gear segment. These models do not really do much, they are more an exercise in getting your gears to mesh, which is not at all a trivial endeavor with sets of this era. I had to use a number of extra washers and brass collars to get smooth gear meshing. The motor is one I rewound, it is running at 3.0 volts and pulling 2.0 amperes in the video. On the front side is a back side is a basic reduction gearbox driven by a worm gear on the motor, the worm gear meshing is the hardest to get right. We then have ladder chain spinning two more gears. On the back side we have a crown gear turning three axels using the cone pulleys with women’s hair bands as the belts. The other side is an eccentric used to rock the gear segment across the saw blade. I really only included it so that one side of the back plate would not be so empty.
– Greg Guidarelli, August 5, 2015