Custom 3D‑Printed Headrest for Quarter Midget Racer: A Mark Two Case Study

When it comes to building end‑use parts, the Mark Two’s reliability and strength open doors that were once closed. While we’ve pushed the printer’s limits in toughness and detail, the size potential for large, functional components had never been fully explored. In this project, we tested those limits by printing a bespoke headrest for Chase, a Quarter Midget driver, delivering both safety and performance.

Quarter Midget Racing Overview

Quarter Midget of America supports youth racing across the U.S. These compact cars, derived from high‑power midget race cars, race on 1/20th‑mile tracks at speeds up to 50 mph. Drivers range from 5 to 16 years old, and precise cornering is the key to victory.

Safety protocols are rigorous. The harness system secures the driver from shoulders down, but the head remains vulnerable to centripetal forces that push it toward the outside of the track. Most vehicles rely on a simple safety net that runs from the roll hoop to the front bracing. While functional, this net is not a permanent or robust solution.

Design Objectives

The new headrest had to satisfy three core requirements:

• Provide solid protection while retaining a degree of flexibility.
• Mount securely to the roll hoop without adhesives or welding.
• Match the aesthetics of a race car and conform to Chase’s helmet geometry.

Material Strategy and Build Process

We used Carbon‑Fiber‑Reinforced Nylon for the primary shell—one of the largest parts the Mark Two can print, requiring over six days. This material delivers exceptional stiffness and strength. To introduce controlled flex, we incorporated Kevlar‑reinforced clamp plates that bend slightly under load, allowing the headrest to absorb dynamic forces without compromising safety.

Mounting System

Replicating the easy‑adjustment of the old net, we engineered a three‑point clamp system:

• Aluminum rods run along the roll hoop, acting as cross‑members.
• Kevlar clamp plates attach to the rods, allowing vertical and lateral adjustment.
• An Onyx bracket with co‑processed nuts provides a third anchor point to the front bracing, preventing cantilevering and distributing load evenly.

This configuration offers a robust, yet adaptable, attachment that can grow with the driver and the car’s evolving geometry.

Finished Product

The final headrest showcases a clean curve that mirrors Chase’s helmet profile, angled to counteract centripetal forces and keep the head centered. The racer’s number is laser‑etched onto the surface, marrying functionality with a polished look.

Race Results

Chase’s first race with the new headrest proved its value—he navigated turns with greater precision and secured a win. The headrest not only enhanced safety but also improved performance on the track.

Interested in the design? The main .stl file is available for download.