August 10, 2018
Its 11pm Friday and we finally got Joule run-ready for our second SCCA event at El Toro on August 11-12th. A driveline failure occurred at our last AutoX event in July, where a set screw holding a key for the chain sprocket failed, causing the right DC motor to be completely disengaged. Our solution to this issue was to lightly drill into the key, creating a divot for the set screw to “fill in” (figure 1). We then applied threadlocker on a new set screw with a degreased sprocket and allowed the assembly to cure for 24 hours, reapplied grease, and initiate testing.
However before testing, we have to service the racecar. With the help of EECS Professor QV, the team established a dedicated Hot Pit Crew, learned how to align Joule and created standardized torque specifications for all suspension components. These initiatives are all leading to the creation of a service manual for Joule.
We aligned Joule to be toe-out in the front and toe-in in the rear by 1/16’, and camber to be set at 1 degree negative. This is a good baseline to start from for an AutoX setup, before further adjustments.
Afterwards we standardized all our torque specifications for suspension, and will test them out by comparing the torque of all nuts and bolts before and after our event on Saturday. This should give us data on what is too tight or too loose or just right to be recorded in our service manual.
Now it's time to test the powertrain! We raised the maximum motor output from 30% to 40%. Test driver Reza drove Joule up and down the hill of Engineering Drive, and the powertrain held together successfully for a few hard runs before Joule spun out on debris on the slick, cool evening road.
After the close call we loaded Joule on the trailer, and sent her to the El Toro Airfield for AutoX!