Monday 2/2 Scrum Notes

On Saturday we test-drove the robot chassis successfully. Without any superstructure on it, the robot is quite light (and fast!)

After testing the conveyor belt and hooks, we mounted the conveyor on the chassis with an back-angle of about 20 degrees. This places the center of gravity of the 37 lb conveyor over the center of the robot. Hooks have been tested and fabricated but still need to be attached to the belt at proper intervals. Testing showed that carpet tape could not support more than on tote per hook, and that attempts to swing a barrel or a tote “over the top” simply tore the hook off its mount.

Great progress has been made on the electronics, and the wiring is nearly finished.

Computations about center of mass, height and stability are ongoing. The current weight (with 14 lb battery on board) is 107 lbs. The rules limit the robot to 120 lbs without battery, so we have 27 lbs of gear and ballast to go before hitting the limit.

With six totes and a barrel aloft, the fully loaded conveyor weighs about 97 lbs and its center of mass is about 44 inches above the floor. Rapid turns and abrupt changes in speed must be avoided! There was a possible issue with inadequate chassis stiffness. Rocking the conveyor lifted just ONE wheel off the ground, indicating an unhealthy amount of chassis flexing. An “X” brace was added inside the chassis but its effectiveness has not yet been evaluated.

Work continues on a mechanism that can lift a barrel and place it on the stack. It is desirable to be able to collect game totes and barrels in any order and any orientation. The most likely mechanism is a four-link, which can be easily telescoped inboard to satisfy the “transport dimension” requirements.

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