This is the 3rd wood mechanical marvel I have designed from thebook 507 Mechanical Movements by Henry Brown which is a reprint of a book first written in 1868. Here is the concept drawing and description of operation from the book:
232. Intermittent circular motion is i parted to the toothed wheel by vibrating
Rather than raise and lower arm B by hand, I wanted to make a crank type
Friction turned out to be a major factor in this model working well. There has to be enough friction between the gear wheel and the rear mounting plate for the gear to stop between indexes. I was careful where I applied the Johnson Wax at final assembly so the friction came out right (no Johnson Wax between back of gear and rear mounting plate, etc).
Here is the finished model:
Here is a close-up of the ratcheting mechanism:
The yellow dyed piece of maple adds some color to the model. This is one of the coolest models I have made.......it terms of mesmorizing to watch it run.
I took this model to work, and my co-workers think it is one of the neatest models I have made. They are also memorized watching the mechanicsm lift the pawl up and over the gear teeth when it indexes