We'd been checking it out for a few years now. Each time we'd say, "yeah, we'll make a car and run next year." But this year we did it. We built a car for the annual Bernal Heights Illegal Soap Box Derby. I've had plenty of hair brained schemes for freaky gravity racers, but I wanted to go family style--with my 6 year old daughter, Dinah. I wanted her to be able to drive, but I wanted to be able to step in in an emergency and take over. And I didn't want the instability and potential crazy handling of the old axle-with-a-bolt-in-the-middle steering. Whether operated with ropes or your feet, that can get weird fast. I remember from my own go cart that my dad and I used to take up in Tilden Park when I was a kid. And, I wanted to have a hardware store aesthetic. In my professional life, I have mocked up plenty of stuff with plywood, some 2x4s and deck screws. I love that stuff. Also, it seems like the right level of resolution for a father/daughter project. She can weld next year.
So I designed a tandem, dual stick cart--D in the front, me in the back. The front wheels are casters with little tabs on the back to lock them. I drilled some holes in the tabs and used those as steering arms, connected by an aluminum L channel. The two control sticks rotate a shaft (2x2 with holes in the ends) that runs down the centerline of the car. The shaft has a little stick poking out the bottom, that moves a pin right and left in a vertical slot in the L channel between the wheels. Simple, direct, and it works great.
My buddy Jon Carver, who is always looking for a fun project, came over for the first night of building. I finished the frame before he got there, and we got it built all the way through steering by the end of the first night. That's him going all cowboy in the second picture from the top.
Next I added seat-backs and Flintstone-style-brakes with a lot of help from Dinah (who does not like the sound of skill saws, if you were wondering). The painting was handled by D and her Mom--but the art direction was definitely D's.
So race day came and we strapped the beast to the roof of our car. But when we got to the top there were park rangers there saying that there would be no racing. A "neighbor" had complained about last year's race to an un-named city official and managed to ruffle enough feathers to get the park service to intervene this year. The officers at the bottom of the hill said that Tom Ammiano, our supervisor had tried to intervene on behalf of the racers and fans but the damage had been done. The park service could not turn a blind eye because of our "neighbor."
There were a lot of disappointed burning man types, families with hardware store projects (like us) and shop nerds that day.
We went home, defeated. But the race did end up going on somwhere else--no doubt a lot less safe than the cordoned off piece of hill in Bernal. You can read more about what happened here.
But hey, we had fun. Here's a video of D and I taking a practice run the weekend before.