First is Aiden then Nathen

Henry had never driven the car before and his first experience was in a race.  Not exactly how formula 1 does it, but he did fantastic.  Noah did coach him on driving the course before it was his turn in the seat.  The video is uneditend and the race starts around 2m 0s, and checkered flag at 12m 50s.

Noah had run the car for a couple hours on that day before the race up at Whisky Hill race way in Palmer ma and was very used to doing the shifting  and familiar with the driving dynamics.  The video is unedited.

Race starts at 5m 40s.

The checkered flag at 16m 24s.  

Splits were L1-2m 06s,L2 - 2m 00s, L3 - 2m 03s, L4 - 3m 08s, L5 - 2m 06s

I wasn't 100% on adding a go pro to the car because as last I checked they weigh something.  When you add things you really need them to make the car go faster or be more reliable.   It was good we put it on as after each race, everyone would cluster around the laptop while the pit captain downloaded and watched the video.

The paddock was conviently right next to pit lane.  It was impressive to see all the cars and teams lined up together.

We were able to mount the stock sturmey archer shifter on the steering wheel like a paddle shifter.  How F1 can you get.  It was easily accessible from the steering wheel and worked easily.

The transmission was tested the Thursday before the race  and it held together whcih was good.  Here is video of it shifting up and down through the gears.

Here's a video of the steering angle sensor.  We welded a little peg to the end of the steering column, then attached a 10k potentiometer to it with a bit of thick wall silicone hose to transmit the motion.  It worked and recorded data, but we need to do some measurement to convert potentiometer values to degrees.

This is a snapshot to the current DA code that is based on a real time clock / sd car shield for an arduino and an arduino uno.  The current feature list is changing but basically it records a csv of at least the following data,  timestamp of the race time, steering angle, brake timestamp, throttle timestamp, battery temperature, voltage and motor current.

Knowing nothing about the behavior of the transmission we decided on Thursday before the race to do data acquisition.  Our programmer wrote up some code for recording the easy ones. Time of throttle on and off, time of brakes on and off, and steering angle.  For the steering angle we added a potentiometer.

The transmission needed to be mounted in a very specific location to clear the batteries and have everything line up so we had to cut the frame and flip the motor to the other side.

Pretty much we had no idea what we were doing. and no time.  The first thing that we could think of that could work was the idea we used in each step of the design.  Dump luck it all worked out in the end.

A template was made to plasma cut some of the metal out of the drive sprocket and holes cut.

The output sprocket was machined out to the size of back side of the SA AW hub, the chrome ground off and welded in place.  The input sprocket retained the center of an original SAAW sprocket but was ground to a circle with a tool post grinder on a lathe.  The input sprocket was then machined out to the size of the outer diameter of the SAAW original sprocket.  The two were welded together and presto transmission.

The sturmey archer AW is a wide gear range and because we had no idea what it was going to do or what would be the best gearing we chose that variant.  The output sprocket and input sprocket were sized to keep the original first gear ratio with the Sturmey Archer's wide gear range of .75:1. 1:1. and 1.25:1.

After the transmission we were developing seemed too heavy we started looking at other options and settled on a planatery bike hub option.  Sturmey Archer checked all the boxes we could think of.

Early on we got ourselves a sister school St Swithuns and they told us that matching the gearing to a course was critical.  A transmission would help with that but it had to be super light.

I had saw Greenpower racing a few years ago, and when COVID 19 shut down regular US FIRST robotics competitions, we decided to build a greenpower spec car.