TEAM 4201 (Feb. 2014) | Page 15

Printing Award

the proper specifications using trigonometry to determine the size and angle of the contours. This was based on a CAD model of the robot and the ball in order to simulate feeding into our system. The effect of tread on the 3D printed part was also modeled in CAD to ensure the dimensions were correct and matched with the ball when attached to the feeder system.

Another design rule, of course, is that the part has to fit into the printer. The initial thought was to print the entire “hourglass” structure as one part to maximize contact with the ball through the apex of the curve, however, our printer had a six inch maximum height. Therefore, we had to split the wheel feeder into two parts so that each could be printed individually, then they were combined together on the axel of our feeder system.

The self-supporting angle rule called for the build orientation to be from the broadest section on the bottom to the narrowest section on top, eliminating any need for scaffolding. In this case, we printed each half of the feeder from the outside, which flares to grip the ball, to the inside, which is narrower to accommodate the shape of the ball.

build orientation to be from the broadest section on the bottom to the narrowest section on top, eliminating any need for scaffolding. In this case, we printed each half of the feeder from the outside, which flares to grip the ball, to the inside, which is narrower to accommodate the shape of the ball.

II-II. 3DP Design Rules Created By Your Team

We are not sure if we created any design rules or just have discovered truths that we didn’t know before this project, but our lessons included:

-We have found that the lowest quality setting of 10% fill for the honeycomb portion of 3D printed structures is almost always the best one to use. We used that for the first draft of all of the parts we designed, and adjusted from there as needed (though it rarely is).