Baja SAE – 2011

My involvement in the the CWRU Baja 2011 car (competition number 62, “Loki”) was much more substantial than it had been in previous years.  Though as manufacturing lead I primarily concentrated my efforts on supervising and coordinating component fabrication, as a senior member of the team I also served as a design consultant, and in the end I also ended up designing the rear stack (the hub assembly and brake rotor).  I was directly responsible for the vast majority of the CNC parts on the car, with the exception of the throttle and brake pedals, which were machined by Jordan Cluts, and the gearbox, which was machined by Elliot Sting.

During competition we had two major issues surface that were not caught during testing.  Due to poor design (improper choice of rod ends and bolts loaded in single shear), we sheared our toe linkage bolts several times.  Eventually both the rod end and bolt were replaced with more suitable components.  During the final event – an endurance race that is exceedingly punishing for the cars – our gearbox failed, pulling us out of the race.

After we returned from competition I was responsible for failure analysis.  One set of gears had been welded to an intermediate shaft to avoid the “hassle” of sending it out to be splined, and the smaller of the two welded gears was stripped of all its teeth.  The teeth of the stripped gear were well within the heat affected zone of the weld, and my assessment of the cause of the gearbox failure was the subsequent wear as a result of annealing the induction hardened teeth.  This assessment directly and substantially contributed to our 2012 team’s decision to have our gears custom-machined out-of-house with desirable mating features, instead of modifying stock gears as we had done in past years.

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