The prompt for this term project was to design a CNC robot arm for cinematographers, and as a team it was our task to choose our target audience, miniature film cinematographers.
This audience requires smooth movement of the camera, various speeds of camera movement, and different angles of the model being filmed. These factors were the motivation behind the choice of our engineering specifications, number of arms, degrees of freedom, and motors of our designs. Below are three of the candidate designs our team iterated, which I sketched. Further below is the sketch I created of our final design, which was created by combining the most optimal features of our candidate designs. The premilinary CAD of our final design, seen above, was created by another team member, but along with the rest of my teammates we aided its creation.
Design featuring two arms, two ball and socket joints for 180 degree rotation in x and y planes, and a slider for smooth translational movement of the camera.
Design featuring two arms, one revolute joint for rotation about the first arm's axis and a universal joint for movement in vertical direction.
Design featuring two arms, a rack and pinion system for rotation of first arm about its axis, a revolute joint (8) for vertical rotation of second arm, and a slider for smooth translational movement of the camera.
On the left are three close-up sketches of various parts of the final design. The first is a close-up on the internal mechanism of the first arm (8), the second a close up of the second revolute joint (11), and the third a close up of the first revolute joint (7).
This final design combines the best features from our previous candidate designs. This includes the rack and pinion system (3&4) which rotates the first arm on its own axis, a revolute joint connecting the first and second arms (11) to allow rotation in a plane and a kill switch (9). The rest of the features are new, and were decided upon by analyzing gaps and issues in our candidate designs. Once the gaps were determined, we brainstormed as to how we can solve them, and those features were added into the final design seen above. Some of these features include the adition of a third arm (15), another revolute joint in between the base and first arm (7) and a helical joint (17). Another added feature is the pulley system inside each arm, which translates the motion produced by the motors, now included inside and at the base of each arm, to each joint at the other end of each arm.