With a small group I created a purely mechanical split-flap timer for a transmission design project. This timer has flaps which turn in time to count down from an hour. There's a dedicated set of flaps for the ones and tens place for both seconds and hours. This means four shafts of flaps each moving at a unique speed powered by one motor. To achieve this my group implemented four belt drives and five sets of gears to a total speed reduction of 1800:1.
On this project I did most of the work in selecting gears and designing and assembling the drivetrain on the clock. I also worked heavily in the calculations below in characterizing our motor and calculating speeds, torque, power, and experienced forces at each stage of the drivetrain.
On this project I did most of the work in selecting gears and designing and assembling the drivetrain on the clock. I also worked heavily in the calculations below in characterizing our motor and calculating speeds, torque, power, and experienced forces at each stage of the drivetrain.
My group did a set of analysis on this system to confirm our motor was powerful enough and loads weren't significant enough to cause failure. This included motor characterization, forces, power, torque, and speed though the transmission, belt tension, shaft deflection, and bearing life. These can be seen at the link above.