13.4 - Implementation

Fabrication and Assembly:

We designed this robot to be fabricated mostly from 3D printed PLA filament to avoid machining. After conducting gear analysis we are able to use two identical large gears to drive the system. The servo interfaces one of the 3D printed links via a cutout. The two links of the mechanism have fillets to connect the raised spacer part of the link with the main body. This is to ease the stress concentrations from sharp edges. Finally, we add metric screws with enough length to account for the spacers, as well as bearings when needed. An important consideration is the tolerance of the holes in the 3D printed plastic (~0.05mm). Here is a render of the final CAD assembly.

Electronic Components:

The electronic components include a 360 degree servo and a DC motor to drive the mechanism. To power both actuators, we used a motor driver to create variable speed and direction, using pulse width modulation (PWM) to control current into the electronics system. On top of that, we have a Arduino Uno controlling the output with some programming in Arduino IDE to adjust speed. Below is a picture of our electronic setup. Behind the top of our links we have a ziptied servo. There is no battery included in this depiction, but we did use one as our source of electricity. 

Bill of Materials:

This table includes all materials that have currently been purchased. Materials will be added as we purchase them.