Duke University Motorsports is a student group that designs and builds open wheel, single seat race cars to compete in the Formula SAE competition sponsored by the Society of Automotive Engineers. The team consists of Duke students from both Pratt and Trinity, in all classes. The purpose of the team is to provide students with a way to gain practical design and manufacturing experience in a fun and challenging setting.

Saturday, April 28, 2012

Progress update, end of April

We're getting close to competition now, and things are moving along.  A lot of the work now is in testing and tuning, and after yesterday's trip to NCCAR, I think the suspension is pretty much set for competition.  We're also working hard on getting the bodywork done.  The molds are almost ready for the layup, so hopefully over the next week we should have bodywork finished.

 Video of Paul Harraka driving the FSAE car.  His help was invaluable in getting the suspension tuning set in a very short period of time.

It hasn't exactly been a smooth ride to this point.  We've had a number of small failures in testing, but hey, that's the point of testing.  It's nice to be able to catch all these problems early, and having time to get the car just right before competition is great.

So far, we had a radiator tab fatigue and break, we've had the throttle cable replaced due to a kink in the cable, we've had to fix the rear wing mounts multiple times (poor surface prep on the epoxy bonds), we've had a spherical bearing pop out of one of the carbon fiber a-arms, I've hit the front wing pretty hard on cones and cracked it, the rear wing started delaminating from the foam, the fan controller literally caught on fire due to an electrical short, the carbon fiber shifter snapped, and now we're having another fuel issue (likely the fuel pump).  I think that's most of them at least.

All these issues have been fixed except for the fuel issue, which we're going to work on today.  Costi is putting in a fuel pressure gauge so that we can diagnose the problem accurately, but we're going to pick up a few more fuel pumps because they seem to die a lot.

Fan controller burnt to a crisp.  Failure mode analysis shows the fire started at the hot wire, likely due to a short to the aluminum case.  The next iteration of the case just uses heat shrink, since from testing of the first controller, heat from the MOSFET was not an issue.
We ran the old diffuser (the heavier one) with the carbon fiber suspension as a precaution; just in case something broke, the diffuser would have gotten destroyed.  Luckily, nothing broke.
 We have tested the carbon fiber suspension and it seems to hold up fine under testing.  Active aero is the last step really, since we've had issues with the hardware.  The potentiometer was faulty, and was causing oscillations and slow response.  That as since been fixed, but we haven't had time to tune aero yet.

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