Baja's New Rear Cage

Baja's New Rear Cage

The big project for Baja was redesigning and rebuilding the rear cage surrounding the drive train. I have spent the most of the year focusing on the design of the rear cage. The original goal was to reduce the amount of tubing used and it was found that we could also easily increase the amount of suspension travel in the process.

The above images are the old car design, focusing on the rear cage around the engine. As you can see, it is a mechanics dream. Not so much for a designer. When I came in this year, in addition to the end goals that I was tasked with, I noticed a lot of, frankly, lazy designing by the previous designer. So I spent some of my time updating the model to match how the car was built. This will be worth the effort when I start running simulations because the data will be as accurate to the real car as possible.

The above images show the new rear cage design! The most obvious change is that the section supporting the engine and transmission has been made narrower to allow for longer suspension arms. In addition to this, some diagonal support bars were added right next to the engine mount to meet a new rule, the big "U" was made into more of a "V", the suspension arms were lengthened by at least 4 inches, and the suspension mounts were attached directly to the rear of the car. The changes are all rather minor but should add up to a car that weighs a bit less and can handle any terrain thrown at it!

This post would be exciting enough if I was only updating on the modeling process, but I have more! Today we started building the new rear cage! From the pictures, you can see that the old rear cage has been removed and the car is still wearing much of the mud/love from California (it adds character). It's a very strange feeling to see half of the car in one place and have your friend walk off with the other half. All a part of the process! Also in the pictures, you can also see many of the components that will become the new rear cage wrapped up in their drawings. I coped all the tubes. Coping is the process of making the notches/cut-out at the end of a tube so it lines up with another tube that it will be welded to. This became quite the ordeal because the tubes to the left under the long ones needed to be coped at a 30- and a 60-degree angle. This meant making out mill do some machining yoga I don't think it's done in a few years and grinding some of it down by hand when it couldn't reach all the way through the tube. In the end, I test fit them all and they fit perfectly! Those will weld up wonderfully.

Tomorrow the team will be installing all of these tubes onto the car. Next up for me is to redesign the rear suspension. As you can see from the pictures, the trailing arm doesn't line up like it needs to. So, I need to redesign the geometry and make sure everything lines up perfectly. After this, I will be running simulations to identify any problem areas and to have hard data on the safety and performance of our car.

Thanks for reading and stay tuned!