In many college competitions like the Formula SAE Electric Vehicle Competition, student-run undergraduate teams go through very rapid design and build cycles over the course of a year to build Formula-style vehicles. The MIT Motorsports Team, one of many entrants in the competition, has been using parts printed on the Mark Two to gain a critical edge. While no 3D printed parts are visible from the outside of their Formula SAE Vehicle, the Mark Two gave these students the bandwidth to focus on machining more critical components work-holding fixtures. The strength and toughness of Markforged materials allowed the 3D printed Formula SAE Vehicle parts to hold up in the shop and on the track.
In these types of vehicles, the chassis is often a complex welded tube structure, and aligning the tubes for welding is difficult but important to the structure of the car, so manufacturing both the chassis and mounts for it can be tricky. As a result, 3D printing is extremely valuable: it accomplishes many difficult or time consuming manufacturing tasks without supervision. The team used 3D printed jigs to orient the tubes such that they could weld the 3D structure in free space, allowing for a more reliable manufacturing operation. The chassis of the vehicle presented other manufacturing nightmares – the frame of the car isn’t the easiest to mount to, especially when they’re trying to fit already complex parts like electronics systems onto a tube frame chassis. It ends up that these geometries become very tricky to make traditionally, so the Mark Two was able to provide ease and flexibility in manufacturing: 3D printing a part doesn’t waste machining time or bandwidth. The material properties of the Mark Two further ensured toughness and rigidity when critical: these parts printed out of other 3D printing materials make have failed and damaged the electronics, but with the high-strength properties of Markforged materials, enclosures were kept safe and secure during the race.
Apart from complex enclosures, the team used a variety of other parts to finalize their vehicle. Their custom drive train design involved a CV joint, a method of transmitting a constant velocity through two shafts at a range of angles. The team was able to protect the CV joint system with a 3D printed CV boot flange, a component reinforced with fiber so that it had the necessary hoop strength to mount to the CV housing and clamp the CV boot on.
These examples and many more on the MIT Motorsports Teams’ vehicle reveal some of the hidden of benefits of 3D printing – although many parts are deep inside the vehicle, utilizing a high-strength 3D printer with robust materials has expanded the team’s bandwidth. The MIT Motorsports Team was able to perform well at competition behind the wheel of a professional vehicle they were able to build in only a few months.