MARVIN IX

Part of the challenge of 2016's FIRST Stronghold was traversing several randomized sections of intentionally difficult terrain. MARVIN IX was designed with the intention of smoothly crossing over or through the majority of these obstacles, including a four-inch tall beam, a foot-high crossbar, multiple types of doors and gates, and specially designed "rough terrain". To accomplish this, the drivetrain of the machine was designed with four wheels per side; one wheel in the front was raised roughly an inch of the ground to raise its center above the top point of an obstruction called the "rock wall", two more were placed at floor level, and then the fourth wheel was raised a half-inch off the ground in order to traverse another obstacle called the "ramparts". This multi-level wheel system accomplished the exact smooth motion over obstacles we were looking for.

The intake designed to pick up that year's game piece, a 10-inch dodgeball referred to as a "boulder", went through three major versions. The first version was designed to double as an operator for opening an obstacle called the "portcullis", but after using it in competition, it was decided the design for this could be greatly simplified. The second version removed much of the complexity associated with manipulating the portcullis, and further strengthened the device. Version three scrapped the aluminum construction of the device in favor of a flexible polyethelene material that only deformed under prolonged force, making the entire system able to bounce back after major hits.

In the final moments of a FIRST Stronghold match, robots must reach the tower placed on the opposite end of the field. For additional points, the robot can grab onto a bar placed high on the tower and pull itself up above a certain height. MARVIN IX accomplishes this through the use of PVC tubing inlaid with constant-force springs to attach hooks to the bar, and then using a Power TakeOff (PTO) system to transfer power from the drive motors to a set of spools attached to climbing cable. With the hooks attached to the bar, the spools wind backwards, shortening the string and bringing the robot up to scoring height.

The launching mechanism for MARVIN IX is deceptively simple. Four welded bars are attached to two small bearing blocks that are then placed on a shaft mounted in the middle of the robot. Speargun tubing is then wrapped around the far edge of the catapult and attached to the base of the robot, forming a high-powered compression spring. To fire, all that must be done is pull back on the system and release it when ready. This motion is accomplished through a custom firing transmission, which fires pneumatic pins to keep the driving spool in a steady, charged position. When ready to fire, the pins release and the spool unwinds at the speed at which the speargun tubing contracts.

MARVIN IX was incredibly successful in competition, going on to become the first MARS robot to go through an event's qualification rounds undefeated, and also the first machine to rank 1st at an event (the only other MARS machine to accomplish this feat being MARVIN XI). MARVIN IX won one Industrial Design award. Final season record was 36-20-0.