Aerospace | Kodura Design

3D Printed Fuselage Design Research

2024 to present

3D printing is a rapidly developing technology that initially was the realm of research and novelty projects but is now being integrated into heavy manufacturing. However, for smaller commercial projects and hobbyist, often there is a gap between understanding of the material properties and limits compared to traditional manufacturing.

3D printed components under load are often sized through a process of enlarging components until they don't fail under stress. Even for consumer grade filaments which do provide some material properties, the complexities that factor into additive manufacturing strength such as temperature, humidity, flow rate, and so on mean these properties have limited use and often designers carry three or four factor of safety on components. While for some projects this is acceptable, in aerospace the limitations on mass and volume mean that components need to better optimized.

This research project seeks to combine the advantages of cheap additive manufacturing and advanced printing techniques to showcase the plausibility of its use in aerospace products.

In summary, the project involves building L1 class test bed with interchangeable body tubes. Based on collected data, an additively manufactured body tube can be assembled and tested against current products such as fiberglass, carbon fiber, and cardboard. This will then be compared on key metrics of performance, including strength, serviceability, cost, Manufacuring time, and flexibility of design.

This project is a collaboration with Hersch Nathan, a fellow former SpaceLex member and expert on electronics and robotic design. See below for his LinkedIn to learn more about him.

Hersch Nathan's LinkedIn

Note: This project is still in progress.

The project can be divided into the following steps.

Build a test Vehicle

The first step is construction of the test vehicle. For this project I based this design on my L1 licensure rocket, however it needed several new features. To accomplish this, I set out to design a new rear assembly. This section needed to complete several engineering design tasks. It needed to house the various electronic components, be easily swappable for different body tubes and be relatively light and more mass efficient than my original L1.

On the electronics side, the vehicle needed to be able to record velocity and acceleration data, as well as strain on the airframe. For this reason, the airframe is covered in strain sensors to collect shear stress data during the flight and feed back to a set of sensor boards. The vehicle also uses an Adafruit Feather board to calculate telemetry data. Hersch Nathan was an exceptional help on this portion of the research project and deserves significant credit for his contributions not only here, but throughout the conception and extent of the process.

Gather Data

This test vehicle will then be used to test several launches. Several materials are commonly used for body tubes, including carbon fiber, fiberglass, and cardboard. With our suite of sensors collecting data, three test launches will provide data on the stresses associated with flight, including material strain and shear, as well as directional acceleration.

This information can then serve as an accurate basis of design for optimizing a 3D printed body tube which can withstand these forces while be as light and efficient per foot of tube as possible.

Design FDM manufactured body tube

The data will allow for several questions to be answered.

Of filaments available, what filaments can meet the design loading without special techniques?
What techniques, such as non-planar infill, foaming filament, multi-filament composites, and traditional plate bending patterns could increase efficiency, or allow for cheaper material costs?

Once these questions are solved, a FDM continuous body tube can be printed in one or several versions for testing, with an appropriate mounting plate.

Gather Final Data and Finalize Conclusions

After manufacturing is complete, the rocket will be taken back to the launch site for several test launches, gathering data by the same methods as before. This information will then be compared against previous flights while taking into account differences in manufacturing cost, reliability, re-usability, and flexibility.

While the goal is to design something that can meet or exceed currently available market options, the research will determine whether this is plausible, and what discuss what techniques or further advancements would be required to either further exceed or meet that goal.

In general, it is to provide an assessment of the current plausibility of this method of manufacturing and design, and to develop a research grade paper on the subject.

Picture of miniature rocket rear assembly at 1/4th scale

Picture of portion of rear rocket assembly and connector plate prototype

Picture of 3D printed rocket rear asssembly

Picture of prototype rocket rear connector plates at 1/4th scale and full scale

NAR L1 ROCKET

2024

After several years I finally had the opportunity to obtain my National Association of Rocketry (NAR) L1 licensing. NAR along with Tripoli provide licensing for aerospace high power explosives throughout the U.S. To obtain an L1 license you must build a rocket of the appropriate class. This rocket must be inspected and approved by the local NAR chapter flight director, and must complete a successful launch and landing with no major deviations during flight or damage. To learn more about the NAR licensure process, see the link below.

On August 10th, 2024 I achieved my license with the successful launch and landing of Forerunner V7, my personally designed and build L1 class rocket. Due to limited access to tools and resources, almost all of the components of this rocket are 3D printed which is fairly unconventional. While this rocket did not have data recording onboard, it had a simulated altitude of 800 feet.

FAR51025U Competition Champions

2024

The SpaceLex Rocketry Club at the University of Kentucky was founded in 2019 with the goal of improving STEM and building Kentucky's reputation in aerospace. After 5 years and countless hours of hard work by passionate students, SpaceLex entered and won the Friends of Amateur Rocketry 51025 Unlimited National Competition in Cantil, California in 2024.

During the 2023-2024 school year, I had the honor to serve as president of the organization, and help finish our two-year project, Meridian, started under former president Mikalia Risser.

I served many roles over the course of this project. I was in charge of the initial airframe design, working on incorporating the required components of the competition while balancing the vehicle's aerodynamic capabilities and budget. As time passed, I moved into a more project management role, helping to make sure we were communicating with FAR, meeting deadlines, and providing a great experience for students.

Meridian surpassed all our expectations, not only working almost flawlessly on launch day, but also ejecting a water payload midflight, and broadcasting live flight data. While it was a close competition, SpaceLex took home a tournament victory, a huge success for our first competition at a national event. You can read an article published in UKNOW on the event below.

Getting to be a part of this experience was probably one of the most exciting moments in my life. Not just for the engineering and excitement of competition, but for getting to be around some of the most intelligent and wonderful people I have ever been lucky to know.

UKNOW SpaceLex FAR51025U Article