Tuesday, October 13, 2015

First Day of Inspections for WSC 2015

Today was the first day of static inspection. I spent most of the day on Twitter, so I'd encourage you to check that out. WSC has pages up for inspection times and status for the ChallengerCruiser, and Adventure classes. Note that neither Antakari nor ITU are listed on the scrutineering schedules, so although there have not been any official announcements of their withdrawls, I think there's no question that they're both out of the event.

Eindhoven was the first team to pass all of the inspections, and Nuon passed static inspection as well. It looks like all the other teams will have to re-present later.

Now for some photographs!

UKZN's Hulamin starting the day off.
The chassis uses a truss structure in the center section.
Push-pull cables terminating on the front suspension
Steering is via push-pull cables on the ends of a
rack and pinion. 

Overall, UKZN's car looks fairly well executed. It utilizes leading arms in the front suspension, and trailing arms in the rear. If you look closely at the chassis pictures, you might note those little worm gear rigs on the top surface, located near each wheel. I'm told these are for changing the ride height at each corner, and are able to be actuated by a drill from outside the car. I'm not sure I like the idea of being able to rapidly chance the suspension setup; it seems like a recipe for badly screwing up the stability of the car.

Teams have successfully done push-pull actuated steering before - notably Bochum's old SolarWorld No.1

Somehow I didn't take any photos of it, but UKZN tilts the entire car to normalize the array.

EPM-EAFIT lifts their shell to reveal...
Two panels of lenses are carried in the front of the car...
...While the cells themselves are carried in the center.
The modules are assembled into the void left when the driver bubble is removed.

There also appears to be some nasty delamination on EMP-EAFIT's array :(
Eindhoven debates with the officials over how far they can tilt their rear panel for charging.

Bochum shows how their array will be normalized.
It seemed very fiddly and took quite a lot of time to set up.
A look under the rear of Bochum's car.
Solar convertible? Yes please.
Nuon displaying their array normalization
The system seems very nicely engineered, but this is as far as it can tilt without violating the top of the bounding box. One wonders what's stopping them (and other teams with the same issue) from tilting the array up further once they're out in the outback...
Oddly, Nuon has placed the battery for Nuna8 front and center, rather than opposite the driver to help counterbalance the driver's weight.
It looks like the only things in the fairing opposite the driver are motor controllers and MPPTs.
Michigan pops up their array to demonstrate normalization. It goes up really quickly, and makes a nice workstand as well when partially raised. 
Semprius concentrator module placed on the ground next to the car. Not sure how Michigan plans to precisely point them...
The other module up near the front of the car.
The top of Stanford's car is permanently installed, but the side of the fairing comes off - revealing this very clean battery installation.
They also have little feet they can bolt on once the side of the fairing is removed
Up she goes...
...and the whole car is normalized.
"Look ma, no hands!"
They seem to have a variety of shims and poles to prop it at different angles.

Big gap in Goko High School's lower chassis - the lower surface in that area is lifted up with the top shell. For ease of driver entry/exit, presumably?
Front suspension. What am I looking at here.
Rear suspension. Seriously, someone help me out. Those suspension members look like plate aluminum, and it appears that they are rigidly fixed. No shocks or linkages to hidden shocks are evident. Is... is this a transverse aluminum leaf spring setup? The mind boggles. (Also, note the 4-wheel steering)
Fire extinguisher inside Goko's car. Not sure what good it does; it's not within reach of the driver. If I was driving a solar car and it caught on fire, I'd concentrate on escaping rather than on putting the fire out. Also note the drivers' blood types listed on the roll hoop.
Siam Tech: WE MOVE WITH THE SUN. Amen to that.

Overall, a pretty solid first day of inspection. On the Challenger front, I definitely expect some shenanigans with array standing as the race progresses. Most teams were limited in how far they could normalize their array by the top of the bounding box, and I don't know what's going to stop them from tilting the array a little further to catch more sun once they're out on the race route. As discussed in a past post, Michigan has carefully designed the car to tilt all the way, but they didn't really show how they were going to point the concentrators - at inspection, they were just leaned against the side of the car.

On the Cruiser side, we saw the big three from 2013 today - Eindhoven, Bochum, and Sunswift. Eindhoven has an extra handicap this year that I forgot about - the array doesn't come off the top of their car; they only can flip up the array on the "trunk". In 2013 they had a set of ramps that they backed the car up onto to angle the entire car towards the sun, but tilting the car in that direction would violate the height of the bounding box this year. I was wondering if they would have something interesting and unexpected, but it doesn't seem like it. Sunswift displayed an auxiliary array panel that they will place over the windshield when charging, but they're kind of in the same boat as Eindhoven - the only normalization they do is flipping up the trunk panel. Kogakuin, on the other hand, will be tilting the whole car - see approximately 0:20 in this video.

Meanwhile, teams are still testing their cars out at Hidden Valley. I didn't make it out there today, but Adelaide is back up and running with their new array, and SunSpec had some sort of problem with their front right wheel. Looks like it was just a flat tire? 

One final note, on tires (it seems like my favorite topic, right?). We've heard from a few teams that the Bridgestone tires have very low rolling resistance - but unfortunately, maybe very low reliability to match. Some teams report very high numbers of flats... When I spoke to some of the teams that aren't using the new tires this year, many of them said they were approached by Bridgestone and offered tires - but late enough in the testing cycle that they didn't want to risk switching.

See you all tomorrow! Punch, MIT, Blue Sky, Kogakuin, Minnesota, and many more team will be inspected.


  1. Fantastic post, as always.

  2. Thank you for this great update and the live-tweets, looks like you were also right on the very limited use of concentrators this time around .;). looking forward to the reports for the other teams.

  3. I greatly enjoyed the story and pictures! Keep 'em coming...