The stability of a 4 bar linkage made it easy to use a single servo to lift the CRATE. It allows for a controlled motion, mechanical advantage, stability, and was efficient with only needing one servo. It seems easily enough to provide one command to the servo to bring the CRATE to the desired height and was easily repeatable. The thick acrylic (1/4") helped in stabilizing the lifting mechanism and also made it space efficient to allow for it to stretch up high when placing CRATEs and staying in tight at the beginning of a match or when not in use. With three ME students on the team, this also seemed like the best option. 

The 4 bar linkage then had the "crate manager" up front which lifted the CRATEs using a press fit magnet and a 9g servo that pushed out the CRATE to place on the STACK

The primary functionality of the left and right towers were to hold the lifting servo and the IR base that held our signal conditioning circuit. These towers also held our buck converters and power switch

The towers were held in place by the tower clamps. These clamps clamped the boards onto the chassis top piece.

The chassis top had holes for standoffs to hold the bulk of the boards: PIC32 boards, power distribution boards, motor driver boards. This piece had an "open" design to allow for various wires. This also held the TOF mount that allowed for our bot to measure the distance from walls. 

The 4 spacers were placed in a rectangular configuration and made with a small radius to minimize their obstruction. Heat set inserts at the top and bottom were used to wedge these spacers between the top and bottom chassis.

The chassis bottom piece held the drivetrain, batteries, servo flags, and IR sensors for tape sensing. The shape of this piece was curved towards to front to prevent from getting stuck in corners and slighly decrease weight. 

The battery mounts were designed to keep the batteries from sliding around but not so much that they were difficult to remove to recharge. 

The 5 IR sensors at the front were held in place with the IR sensor mount that was screwed into place. These 5 IR sensors were placed as far forward as possible to allow for easier line following. 

The wheels chosen were 72 mm, 30A durometer wheels to allow for a high amount of traction and thereby decrease any slipping. These wheels were great when clean, but the field constantly made them dirty which sometimes caused them to slip. This was only an issue while testing and debugging as we had our wheels cleaned for checkoffs, grading, and the competition.

The pillow blocks held small bearings that minimized the footprint of the drivetrain and reduced the radial load on the motor shaft. 

5mm flange couplings connected the motor shaft to some flange adapters that connected the flange couplings to the wheels on both sides. 

The motors mounts had screw holes to hold the motor in place and onto the chassis. 

The servo flags on the right and left had blue and green flags controlled by 9 g servos that denoted the game start, side, and end.