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Team Speed Racer
Soap Box Race Los Angeles

Building the Chassis of the Mach 5

Our team learned a lot last year about how to build an effective car. We learned what worked and we learned what didn't work. So this year we are taking that knowledge and we are applying it to our new vehicle.

The first step was deciding on the driving position and chassis design. We started with out theme, Speed Racer and looked at the vehicle. How can we build a chassis that supports this body and is as light as possible? We decided this year to go with a round tubing. We selected a .065 wall DOM tubing for the vehicle. The Weight, strength and cost were all pretty attractive, so we got out the tubing bender and crossed our fingers. (our tubing bender is rated down to .090 wall thickness, so there is no telling what may happen)

We sat down with some pieces of wire, sketch pads and pens and twisted some wired up to get some ideas out. Eventually we came up with a basic plan.


The plan was taken to the shop with a set wheelbase and wheel width. We then started bending tubing.




Each bend had to be accurate, however there were definitely more than a few mistakes to go around. (originally we actually built the chassis with .120 wall tubing. unfortunately at nearly 100lbs this was going to be a problem, so we had to start over)




At this point we had two frame rails but needed axles and cross bracing. We started by cutting our cross pieces then coping the ends so it would fit properly and weld in nice and strong.




Once we had everything cut, coped, measured two or three times and ready, we layed it all out and prepped for welding. James welded the chassis together and in the process gave himself a sunburn since he didn't seem to remember long sleeves that day.




Meanwhile, Jeremiah and Josh were busy working on steering arms and axle spindles for the vehicle.



Once the welding was done, we mounted up the steering spindles and the rear wheel axles as well. We put a 3 degree camber and 5 degree caster in the system to help with handling, however we will see how that works out.

We were then able to start working on our steering. Steering arms were welded on to our steering spindles, then aluminum rods were machined, drilled and tapped to hold onto the heim joints that would allow us to adjust our alignment later if it became important.





After the basic steering was put together we moved on to our steering wheel and column. Two heim joints were used to hold the column in place. The column was made up of a steel shaft that we welded a tab on the end of.



At this point we were able to take it for a spin! Wheels were installed and seats were put in


We made a makeshift steering wheel, then we took it out for a test drive.


We discovered that the vehicle is great, however we do have a steering issue to work out. It turns out that our steering arms are causing some odd steering angles.

Here is a video of the progress so far, check it out!

Next up, we will fix the steering, make some axle nuts to hold the wheels on and install the brakes. Soon we will making a steering wheel and possibly weld in a few more pieces to stiffen up the chassis. Stay Tuned!

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