TWITCHY THE ROBOT

MECHANICAL DESIGN

We designed twitchy to be modular

chassis

Designed to fit through a 14" x 18" gate while also having room to hold all of the electrical components.

claw

Designed to sweep and pick up ewoks that are along the path of the robot. We avoid having to detect anything by dragging the ewoks along with the robot.

basket/lift

Designed to have enough space for all of the ewoks plus Chewbacca while fitting on top of the chassis. A linear movement system is used to lift the basket.

bridge deployment

Two small servos are used to hold bridges in place and the bridges are deployed using pressure and gravity.

Download Design Proposal

chassis

The final chassis design has all of the features necessary for every other module to attach. It also incorporates useful holes for screws or wires and slots for any necessary adjustments when mounting other parts.

The large box on the back holds the TINAH computer board as well as the Barber-Coleman motors for the back wheels. Because all of the wiring goes to the TINAH, we had to consider where to put useful holes to run the wiring down the chassis neatly.

This design took many iterations as more and more features needed to be added. However, because of the modular design, the chassis was the only thing that would need to be changed and everything else could be worked on separately.

claw

The claw was designed to avoid ewok detection completely. This increases reliability and efficiency.

The claw would stay open and deployed while the robot is running so that any ewoks in the path would get swept up and dragged along. The claw would then perform a pick up maneuver at set points.

While the claw itself was laser cut, the part that attaches to the chassis was machined from a piece of metal to ensure stability.

basket/lift

The basket is designed to hold all of the ewoks and Chewbacca while still fitting on top of the chassis. The basket was also designed to be lightweight and to maximize useful space, holes were included in the walls that were large enough for parts of ewoks to slip through but never a whole ewok.

The basket lift system uses a Barber-Coleman geared motor and a string to lift a linear drawer system. This allows the basket to be lifted easily no matter the weight and could move as fast as we want.

bridge deployment system

The bridge deployment system went through the most design iterations out of all the modules before finally settling on this simple design. The two holes are cut out for small servos which both hold and deploy each bridge, one at a time. This is possible to a clever keyhole design on the bridges. The first bridge would drop when the servo horns point horizontally while the second would deploy when the servo horns point vertically.

ENGINEERING PHYSICS PROJECT LAB 2018