The transmission references the components that go from the motor to power the top joint, which acts as a knee. It was determined that to provide the necessary torque to the knee to walk (a fast movement) and climb stairs (a slow movement) the transmission needs to have a gear ratio of 500:1. The drill provides a transmission of 65:1, so the gear ratio from the motor housing to the top joint will need to be 7:1. This is accomplished through two stages.
To complete this subsystem, you will need to disassemble the Makita drill. Please make sure that you have completed all other mechanical assembly steps before removing the motor and transmission from the Makita drill.
Step 0: Review design files and print motor and power electronics housing
Please review the design and print files here. Please print the motor and power electronics housing. The motor housing should be printed such that the internal features are facing up. The power electronics housing can be printed in most orientations.
Step 1: Remove support material from 3D prints
The following video will demonstrate how to remove support material from the 3D prints.
Step 2: Remove motor and transmission from power drill
The following video will demonstrate how to remove the motor and transmission from the power drill. Do not proceed if you have not completed all prior mechanical assembly processes.
Step 3: Motor, Transmission, and Power Electronics Integration
The following video demonstrates the process of assembling the motor and planetary transmission unit and the integration of this unit with the battery and motor controller.