NASA MICROGRAVITY RESEARCH
Luis Luna, a former mechanical engineering student at Miami Dade College and current student at Florida International University, enlisted the help of Autodesk and Renishaw to manufacture a bracket he designed for a rocket for the NASA Microgravity Competition. The parties collaborated with Fusion 360’s generative design capabilities and produced the part on a Renishaw metal additive manufacturing system. In the coming months, Luna hopes to get the bracket finished and machined at the Autodesk Technology Centre in Birmingham. Luna’s first drop test was successful, and he continues to develop his next rocket for the 2024 competition.
Luis Luna, mechanical engineering student.
As a large four-propeller drone lifted Luis Luna’s microgravity drop vehicle rocket prototype about 500 meters into the air, the mechanical engineering student waited for the moment of truth. Then the prototype detached from the drone. Four seconds later, its parachute deployed and made a smooth landing in the grass of the Florida Polytechnic University where the drop tests were held.
It was the culmination of months of designing many rocket prototype iterations as well as simulation tests for Luna. He took on the challenge of participating in the NASA Florida Space Grant Consortium (FSGC)-sponsored Microgravity Competition as an extracurricular activity and used the Miami Dade College maker’s club lab to design two rocket prototypes. Along the way, he would find some most helpful assistance from Autodesk Fusion 360’s generative design capabilities and Renishaw’s metal additive manufacturing (AM) systems.
Luna and teammates prepare the first rocket prototype attached to a drone for takeoff.
Luna has been using Fusion 360 since 2017 when his brother introduced it to him as a new software for designing. While Luna says he learned the essentials of Fusion 360 in only two weeks, these two microgravity rocket prototypes presented major new challenges to the young engineer. His first rocket prototype would launch via a drone, but the second prototype would have a solid propellant rocket engine. So all the component parts of the rockets had to meet many project requirements and specifications to take the specific loads and stresses that accompany a launch.
One part in particular—the motor mount bracket for the second rocket's prototype—needed special attention to keep its weight low and its mechanical strength high. Luna applied Fusion 360’s generative design capabilities to arrive at a solution for the bracket, and then approached Autodesk for help in 3D printing the part using metal additive manufacturing.
That led Luna to Lee Sanders, an Autodesk senior technology consultant, who also solicited the help of Carl Hamann, technical sales & business development manager for Renishaw (Canada) Limited. Together, the three worked out a way to refine Luna’s bracket design specifically for the manufacturing process they envisioned. “Generative design is a great enabler to get to a good starting position where you're sort of 80% there,” Sanders says. “Then we've got to tweak it to make sure it makes it through manufacturing. Carl helped with putting extra structures in there. He was able to foresee issues where maybe the algorithms didn’t.” When finished, Luna’s motor mount bracket design went to Renishaw UK for 3D-printing on a RenAM 500Q metal AM system.
In the end, after many design iterations going back and forth between the collaborators, Luna came away with a motor mount bracket that weighed 704.28g, instead of the initial 1,608g. Generative design in Fusion 360 helped him reduce more than half of the part’s initial weight while maintaining the strength and thermal stability needed to withstand the extreme conditions of a rocket launch. “Working with Lee and Carl has been truly an honor and a great learning experience,” Luna says. “I learned many really important small details about metal AM regarding the manufacturing process and the design requirements a CAD model needs to be 3D-printed properly.”
“It is awesome to see the design work being done for student competitions like this one. Helping to take students through the design and manufacturing end-to-end workflow will help strengthen their knowledge for when they move on to industry and become the next generation of engineers and designers.”
—Carl Hamann, Technical Sales & Business Development Manager, Renishaw (Canada) Limited
Luna’s first rocket prototype ascended to a height of 500 meters before detaching from the drone and deploying a parachute.
Throughout his past and ongoing work on the microgravity competition, Luna has also relied on Fusion 360’s simulation capabilities to validate that designs would perform well under real-world loads and stresses. He’s also taken advantage of static stress analysis for the motor mount bracket, rendering, and collaborative CAD modeling functions in Fusion 360. He has worked closely with his fellow student team members, including Rodrigo Yurazcek (nozzle design and CFD simulations), Manuela Becerra (engine propellant chemicals), and Isabella Crespo and Osheit Chang (coding and flight simulations).
Due to the input of everyone involved, Luna says the FSGC organizers deemed his first drop test the most reliable of the day. However, even when the second test didn’t go as planned when the parachute did not deploy, it was still a worthwhile learning experience. “It offered an opportunity to gain proof of concept for an interesting feature I had integrated: a flexible plate made of TPU filament separating the payload (CubeSat 3U) from the nose cone to absorb the force of impact,” Luna says. “Thanks to that feature and the FEA [finite element analysis] simulations I did in Fusion 360, the CubeSat 3U survived the crash.”
Static firing test rig, titanium bracket (position, centered)
With Luna’s first rocket prototype tested, his next milestone will be to prepare for and conduct a static fire test on the second rocket prototype, which has the generatively designed and metal 3D-printed motor mount bracket and the solid propellant rocket engine. Luna plans to have the rocket engine completed by the end of summer 2023. At Florida International University, he looks forward to continuing to refine and test it with the goal of entering the rocket into the microgravity competition in April 2024.
Extracurricular competitions like this no doubt strengthen students’ aptitude as they head into their career pursuits. However, in this case, it could mean even more, since the bracket workflow developed from the collaboration between Luna, Sanders, and Hamman has the potential to be used in other applications. Hamman says, “Renishaw’s additive manufacturing experience paired with Autodesk’s extensive generative design tools within Fusion 360 have transformed what you can do to add engineered performance to a component.”