Formula SAE Competition Update

We might as well start the story on the 22nd of November - Launch Night - where the team presented a stunning but ultimately incomplete vehicle. With the car shipping only 3 days later, a few last minute manufacturing jobs were ticked off and the packing commenced. 

But it's never quite that simple! 

On Sunday the 29th, the gearboxes were assembled for the first time. Rather, the gearboxes were attempted to be assembled for the first time. A communication error resulted in our motor gearbox's ring gear being manufactured well undersize. A two pronged attack was started on Monday to ensure working gearboxes met the car in Melbourne. The first prong involved making new gears from scratch - milling the raw steel, shaping the teeth and then hardening the gear. The second prong involved wire cutting the undersized gears (wire cutting can still cut hardened gears!) and then hardening the resultant afterwards. In no particular order, we undeniably would have been up a creek without a paddle were it not for EG Whiter, Torks, BOP Gear Cutters and Heat Treatments expediting our time sensitive jobs to ensure these gears were produced in only 3 days! 

Once the team landed in Melbourne on the Thursday, we collected the car and set up our workshop away from workshop with Monash Motorsports. A reasonable amount of assembly still had to occur, but thankfully we were not neck deep in manufacture in the Monash workshop. 

After six days of assembling, fiddling, fettling, debugging and - finally - spinning wheels, we got out testing the day before the competition began. The car ran a steady but reliable 20 minutes in the morning before a data crunching and accumulator charging break took place. We then returned for another 20 minutes of predominantly reliable running in the afternoon. 

The team spent Wednesday night tidying up the car, performing some last minute rules legality changes before getting some well deserved rest prior to the start of the event.

Thursday began early. A core team went to Monash to continue working on the car prior to packing up and driving to Calder Park Raceway. We continued finding things to fix and change prior to the first inspection, but eventually entered EV1 - a general electrical safety inspection to make sure we dotted our i's and crossed our t's. Three minor issues were identified which we fixed prior to going home for the night. 

On Friday, we re-entered EV1 inspection and were cleared to go to mechanical inspection. Coincidentally, another three minor issues were identified. The car was required for the Design Event, so a forced break was had while the design presenters impressed to take third place!

Shortly after Design wrapped up, our Business Presentation team were convincing the judges that our concept was worth their investment - and we walked out with second place and a trophy for our efforts! 

The car returned to the pit bay and was fervently worked on before another forced break - the Cost Event! Cost team impressed as well, resulting in another second place (and another trophy!)

A milestone for the team - this year is the first that we have been on the podium for all three static events! A marked improvement which clearly shows that effort in is proportional to results out. 

We finished modifying the car to clear mechanical inspection. The inspectors commented on how "everything is there for a reason" - a nod to our simple and systematic approach to vehicle design. 

Following the mechanical inspection, the car performs a tilt test. To simulate 1.7g of lateral acceleration (cornering), the car is tilted to 60 degrees. If the car tips, it is not fit for purpose! Fortunately, the car did not tip and the "HELP!" sticker was ignored. 

We had been planning to attempt EV2 - the second electrical inspection where all startup and shutdown procedures are tested. A pre-inspection check was performed which identified an under-voltage cell (one of two hundred and forty which comprises our accumulator). Knowing we had no hope of completing the inspection with the dud cell in the pack, we pulled the accumulator from the car and headed to Monash for some open heart surgery. 

After a sleepless night, the accumulator returned to Calder Park and we flew through the inspection. The final hurdle for us was brake test - but we had performed many previously and were confident in the car's ability. On the second attempt (who knew drivers are more gentle under pressure?), we got four thumbs up and were off to compete in our first ever electric vehicle dynamic event!

After several false starts - if you could call them that - the car made its way onto the Skidpad track with 10 minutes to go. One quarter of the way through, the car shut off suddenly. Our hopes of completing the event were dashed. In the attempts to speed up debugging previously, the brake system plausibility device (BSPD) had its sensitivity turned up. This allowed the device to be operated by the force of a hand, rather than by the force of a foot. This small change meant that even a driver lightly resting their foot on the brake pedal shut off the car. Despite this, the team saw the silver lining - this was our first time with an electric vehicle competing in a dynamic event!

With an hour's break between Skidpad and Acceleration, the car went into the pits for some modifications and checks. Another issue presented itself in Skidpad - the two sensors reading the accelerator pedal input were suffering from noise issues. If they did not agree within 10%, the car shut off. To remedy this, the magnetic rotational sensors were replaced with the linear sensors from our dampers! While not quite giving the response a driver expects due to the conversion of angular to linear motion, they did result in a running and rules compliant car. 

After some time spent at the test track to ensure our solution was in safe working order, we managed four acceleration runs with no issue! The best of which was a cautious but respectable 4.9 seconds, earning fifth place out of the nine attending EVs. 

The whole team returned to our hotel and slept well on Saturday night. The car, as well as all car components, remained locked up at Calder Park anticipating our return early in the morning to charge the accumulator. As with most race cars, minor changes and checks were performed, but we eventually made our way to the start line for the Autocross event!

Our lap started with a flier, but the car soon petered out and came to a stop. We were confident that the previous issues had been resolved - meaning a new one was rearing its ugly head. After a few intermittent laps, we posted a final time a full minute off the pace. 

Data analysis showed an issue with power draw from the inverter - when the wheels slipped on corner exit acceleration, they would exceed 15000rpm while still drawing the requested torque. This saw the motor power draw exceed the supply ability which caused our inverter to stop the car. 

Our fix was to limit motor speed to 13000rpm and perform some testing prior to endurance. The testing was in the form of donuts on the test track - which amused drivers, engineers and videographers alike! What better way to simulate on track wheel spin than with on track wheel spin?

Having posted the slowest EV Autocross time, we were up first for EV Endurance! We had an absolute blinder first lap - but ultimately that became our first and only full lap at competition. The car shut off 2 minutes into the event and was unable to be recovered. A mix of deflation and elation between different team members made for a strange post-competition celebration.

Ultimately, we improved significantly on last year's competition performance. We made it onto the track, completed a dynamic event and competed in every dynamic event! We realised our potential with the static events to take podium places in all three! 

We end the year with a team inspired - and realistically so. Most years, the conclusion of the event sees so many going "let's try radical concept a, b and c! Redesign the car and start fresh, implement all of these ideas to make the car even better!" This year, the consensus is that we have a great package, we just need the time to iron out the kinks. It's reassuring to end my time as Team Leader with a team that finally realises how to succeed in Formula SAE - you don't need to start from scratch every year. The most successful cars are those where minor change occurs over time - where success is built on instead of paved over. 

As of Monday next week, I formally hand the reigns to Lizzy Grant. I move to our Chief Engineer role for 2018, remaining as attached and involved as ever. 

As always, thanks for your support! It means the world to us. See you next year!

Blake Roberts
2017 Team Leader