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Component Design
Component Design
The Halo Dome
The Halo Dome
The Halo Dome design floats around the head, offering comfort and freedom of movement while maintaining full head rotation. Attached to the back of the roll cage, it is securely suspended. Made from lightweight, durable fiberglass, the Dome is crafted using a 3D-printed mold and multiple layers of fiberglass for strength. A clear polycarbonate visor ensures maximum visibility while keeping the head safely inside the Dome during a collision, addressing previous designs' limitations with visibility or head safety. Due to an issue during the fiberglass curing process, the visor is unable to retract.
Halo Dome with polycarbonate visor
The Roll Cage
The Roll Cage
The roll cage design draws inspiration from race car roll cages, prioritizing factors such as weight efficiency and impact resistance. Constructed from polycarbonate tubing, it benefits from strength and ease of molding. Its viscoelastic properties ensure that minor impacts won't compromise material integrity. To enhance strength, the connections between tubing segments were reinforced with fiberglass. This reinforcement ensures the joints withstand repeated impacts without weakening the structure. Additionally, the hip component is machined from aluminum 6061, housing a needle bearing that allows rotation, enabling the user to lean when needed.
Finite Eelment Analysis
Finite Eelment Analysis
Initial FEA simulations revealed that most of the force was transferring through the spinal cord rather than dispersing throughout the roll cage as intended. The team hypothesized this was due to insufficient frontal support for the Dome and primarily lateral struts on the back.
The current design, shown to the right, addresses the earlier issues by incorporating additional Dome struts for enhanced frontal support and transitioning to diagonal spine supports for better load distribution. These adjustments were made to provide a more stable structure and ensure that forces are more evenly dispersed throughout the system. Real-world testing of the updated design confirmed its effectiveness, showing a significant improvement in force distribution during impact, ensuring better protection and stability for the user.
Updated diagonal back design.
Anchor Points
Anchor Points
Anchor points are a crucial part of the design, enabling the distribution of force to key areas of the body. Positioned at the chest, hips, and back , they direct the force to regions with dense cortical bone or large muscle groups that can absorb the impact without causing major injuries.
Each anchor point was 3D printed using ABS for its lightweight, durable, and easy-to-fabricate properties. The anchor points were sewn directly onto a nylon strap vest, ensuring a secure yet flexible connection while maintaining comfort for the user.
Future iterations should explore injection molding for it's superior strength and resolution properties. 3D printing was used solely for prototyping and testing purposes.
Hip Pivot
Hip Pivot
The initial design reduced hip bending ROM by over 70%, prompting a redesign. Hip pivots were critical for maintaining the desired ROM while withstanding radial forces during impacts. The pivot consists of the housing, a 22mm needle bearing, and a connecting rod and cap. The bearing was fitted into the housing with a clearance fit and secured to the hip anchor point.
With this updated design, hip bending was only reduced by 2.3%, greatly increasing the comfort and usability of the Halo Helmet while maintaining a structurally sound design.
All machined components were made from 6061 T6 aluminum for its strength and lightweight properties. To prevent galling from repeated motion, anti-seize was applied to the threads, and a 3D-printed PLA washer (not shown) was used to prevent direct contact between surfaces.
Exploded view of the hip pivot components.
Early On...
Early On...
Initial Design Setup and Process
The initial design brief for the project emphasized separating the roll cage and protective headpiece into two distinct components. This approach allowed the head to move freely within the headpiece, ensuring that the helmet would not restrict natural motion while the roll cage provided robust force redirection and structural support. Early sketches from the sponsor, Paul Shockley, showcased this concept, highlighting key structural features and emphasizing modularity to facilitate adjustments during testing.
Paul Shockley played a pivotal role in guiding the early stages of the project. With his extensive network of contacts specializing in various fields, including biomechanics, materials engineering, and safety design, he provided access to valuable expertise that significantly shaped the direction of the project. His connections ensured the team had the necessary resources to tackle complex challenges related to material selection, impact simulation, and structural design.
Discovering the Halo Concept and Patent Research
During the research phase, the team discovered an expired patent that validated the feasibility of integrating such an approach into the project. This concept served as a proof of principle, inspiring adaptations for a lightweight, mobile-friendly solution suitable for sports like mountain biking. Further research into similar designs highlighted the potential for innovative improvements to enhance safety and comfort while adhering to biomechanical principles.
Expired Patent - https://www.nature.com/articles/sc20091
Meetings with Professionals
Meetings with Professionals
Meeting with Makerspace Expert
On November 14, 2024, the team met with David Lesser, an expert at the Makerspace, to discuss the design process and steps for prototyping and fabrication. The meeting provided critical insights and actionable steps to refine the project approach. Key takeaways included the importance of splitting into subgroups for efficient design and learning, incorporating customer feedback to shape iterations, and consulting with Paul Shockley on biomechanical considerations. Lesser advised starting with a broad, exploratory design—described as "big and dumb"—to avoid perfection paralysis and focus on functionality. He emphasized the importance of understanding time dynamics in reducing impact forces and suggested that it was acceptable for the headpiece to allow slight "bouncy ball" motion to dissipate energy safely. Weekly checkpoints were established to track progress and maintain momentum. Additional discussions covered fabrication materials, cowl design, and integrating biomechanics into the overall framework.
Meeting with Biomechanics Expert
In a pivotal meeting with a biomechanics expert, the team explored advanced methodologies for simulation and analysis, which would significantly inform the roll cage and headpiece design. The discussion emphasized leveraging tools like OpenSim for simulation and OpenPose/OpenCap for motion tracking to define the range of motion and forces acting on the human body during high-impact scenarios. These tools provide detailed insights into joint constraints and motion patterns, helping the team refine the protective design to ensure anatomical compatibility and safety.
Meeting with Electronics Shop Manager
While on the search for an analytical way to test and observe impacts on the Halo Helmet, the team met with Steve Roberts. Steve created a simple voltage divider circuit using a resistive force sensor and a fixed load resistor. During the demo, it can be seen that when the padded sensor surface is hit with a hammer, a rapid and consistent response is recorded. After further discussion, it was settled that accelerometers would be used in tandem with Arduinos to record the effects of an impact on the anchor points due to the fact that certain points would experience a pulling force as opposed to pushing.
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