Our first year swerve
After using a kit of parts west coast drivetrain for the past couple seasons, we wanted to expand our capabilities by getting a swerve drive in the off season. It was important to us that the swerve drive can be used for multiple seasons so that the expenses could be cut down. We also wanted to give the software subteam plenty of time to work on it in the offseason, so we wanted a swerve drive that could be assembled fast.
Design and Prototyping
A couple different options arose for the swerve drive. Making a custom swerve would be very costly, and take up too much time, so we decided to purchase COTS modules. After discussing for a while, it was decided that the SDS mk4i would be the best module for our team because of its speed, reliability, traction and durability. The modules were ordered, and arrived in October. They were assembled by some of the newer members, and installed on a simple wooden chassis so that software could test and develop the necessary code.
Final Assembly and Modifications
Once the challenge was revealed, it became evident that the swerve drive would be a great drivetrain for this year because of the minimal obstacles and necessary speed and maneuverability. The chassis was custom designed and machined out of 2” X 1” aluminum tubing, which allowed us to make custom key slot bumper mounts that made mounting bumpers fast, easy and reliable. Part way through the competition season, a team made a post on Chief Delphi that mentioned an issue with the retaining screw on one of the gears shearing, causing significant damage to the module. As a precautionary measure, we promptly ordered the replacement part made by SDS, and installed it on all four modules. Before competing, we realized that we would need to replace the treads every so often, so rather than ordering new treads from SDS, we ordered a large sheet of the same material and cut it on a laser cutter so that we could swap them easily at competition.