2012 FRC Engineer's Log; Avery Hughes 3189: 14.1.12 Weekend

Wow! It has been a long, roboticcy weekend. After the meeting Friday night ending at 10, my dad and I got up early Saturday morning and hit home depot for emergency prototyping materials. We spent the morning fabricating a proof of concept for Project ÜberTank. The results were rough, but worked. We ended up with a three-link chain, each link with two rollers perpendicular to the axis of tread rotation. The chain/tread has incredible traction, however rolls sideways with very low friction exactly as intended.

At the Saturday robotics meeting, I presented the prototype to the team and spent the day working out design issues with the robot chassis and drive-train layout. All of our major issues were resolved, and we ended with a modular design that will allow for the possibility of both traditional treads, and ÜberTreads.

Here are some CAD screen captures of both version 1.0 and 1.1 of ÜberTank.

"Linkage Plate" from version 1.0: A plate of aluminum with slots machined for attachment of the roller axles, as well as depressions to prevent slippage on contact with a drive (or floating) sprocket.

Single version 1.0 link.

Alternate view of version 1.0 link.

Full assembly of six version 1.0 links.

Single version 1.1 link.

Alternate view of version 1.1 link.

Assembly of six 1.1 links. In 1.1 the drive or floating sprockets have concave teeth on which the crossbar between each linkage bar can rest. This design should reduce weight and wear due to the fact that the round crossbar will wear significantly less than the filleted depressions in version 1.0. Also, due to the decrease in the amount of material, it is possible to use a lower-wear material for the crossbar such as stainless steel (as opposed to aluminum).

While I don't have any pictures of the fully assembled prototype yet, I plan on taking some tomorrow (Monday the 16th) in the robotics lab. Here are a few photos of the prototyping process Saturday morning.