Spring is approaching and if your neighborhood is like mine, it seems like every other house has a portable basketball hoop ready for players to heave up three-pointers from all directions. As I was slowly driving down my street, keeping a close eye out for kids and bouncing basketballs, I was thinking it was time my kids graduate from the “Tiny Tikes” plastic hoop to a legitimate basketball hoop system. With this thought in mind and a specific idea of the necessary features required, I started looking online for a portable basketball hoop.

Surprisingly, my search ended with the realization that a system that met all my requirements did not exist. If the design met most of my criteria, it cost more than $3,000, and if it was in my price range, it didn’t have several key features. Since I am a mechanical engineer who had access to sophisticated engineering, design, and optimization tools with Altair HyperWorks™, I decided I would design my own.
First, I defined the design criteria to include the ideal features I wanted:

• Adjustable rim height – Ability to easily and safely adjust the rim height from 7 to 10 feet to accommodate various ages and skill levels
• Playability – Good stiffness so the ball plays off the rim and backboard properly and mass distribution to keep the system stable and grounded
• Safety – Distance from the plane of the backboard to the base and structure should be 48 x 78 inches and the center of gravity should be as low and as far away from the rim as possible
• Compact and portable – Ability to fold the structure to fit into a standard garage (84 inches high) and easily position it in different locations for storage
• Durable – 8- to 10-year lifecycle and able to withstand outdoor conditions (UV-light, rain, snow, etc.)
• Affordable – Utilize inexpensive manufacturing, materials, and standard off-the-shelf products while optimized to minimize material and cost
• Easy to assemble and manufacture – Ability to assemble quickly and accurately and designed so that current manufacturing techniques can be utilized

Figure 1 - Starting layout and geometrical constraints

As these are the initial steps in the simulation-driven design process, I did not attempt to meet all the stated design goals at this beginning stage. My main focus was on the mechanism, structure, and mass distribution. Cost and manufacturing were considered but were not drivers of the design at this point in the process.
There were several challenges to tackle with this system that I categorized into three main buckets: geometrical, structural, and analytical. Early steps address several of the geometrical challenges and many of the design goals were achieved through careful geometrical design of the structure and mechanism. This included creating a mechanism to keep the backboard perpendicular to the ground at all the variable heights, folding the assembly into a compact structure small enough to fit in a standard garage, and maintaining the 48 x 78 inch “stay-out” area for playing rim heights to improve player safety. I utilized Altair Inspire™ for its intuitive geometry creation tools and Altair Inspire Motion™ for its motion simulation technology to visualize the kinematics. These were perfect tools to quickly mock-up designs, evaluate the motion and troubleshoot problems.

Figure 2 – General layout at 10’ position and folder position

Once the overall layout of the mechanical system was complete, I then focused on the structural challenges, which included ensuring it was sufficiently stiff, minimizing the amount of material used, and making it strong enough to withstand common wear and tear. These challenges inherently clashed with each other. Typically, a structure with more material has more stiffness and is stronger, so generally minimizing the amount of material would make it less stiff and weaker. The key is to put material only in the necessary places to support the expected loads that the system will experience throughout its life cycle. Luckily, I didn’t have to guess and iterate on this problem because Altair OptiStruct™ topology optimization did it for me.
The last set of challenges were analytical, which was difficult because the assembly of the basketball hoop experiences various loads in several different configurations. Typically, in finite-element analysis (FEA) one configuration is analyzed and optimized at a time. To optimize the structure properly, load cases in all configurations needed to be simultaneously considered during the topology optimization phase. This required at least five different finite-element models to evaluate the five different configurations (7 ft., 8 ft., 9 ft., 10 ft., folded) and load cases. During the topology optimization, the five models were analyzed concurrently to determine the optimal placement of the material. With Altair OptiStruct’s multi-model optimization (MMO) this was possible with very little effort.

Figure 3 – Standard views of current status of the design

The next steps will include pinpointing which materials work best for the different components, identifying what manufacturing methods make the most sense, and continuing to optimize the stability and performance. Taking a simulation-driven design approach with Altair HyperWorks accelerates the design process and produces better products. This basketball hoop system is a fun example of how simulation-driven design can be applied, but this same process could be applied to countless other products and structures. Using simulation to speed up the design cycle, troubleshoot and visualize the mechanisms, and optimize structural components are just a few of the many tools Altair can offer.
Want to learn more about the details behind this experiment? Click here for more details about the initial steps to take a simulation-driven design approach for a portable basketball hoop system.
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Rendered animation created in Altair Inspire™ Studio 2019.4