Vintage-Style Universal Pull-Switch Knob

Bring a touch of classic 1960s automotive styling to your next project!

Originally reverse-engineered for a vintage 1960 Holden FB Special dashboard restoration, this beautiful knurled pull-switch knob is designed to be completely universal. Whether you are restoring a classic car, building a custom sim-racing rig, designing retro arcade cabinets, or working on any DIY electronics project that requires a mechanical pull-switch, this knob adds the perfect vintage flair.

Key Features:

• True-to-Era Design: Features a classic tapered profile with deep, ergonomic knurling for a satisfying grip.
• Smart Two-Piece Assembly: Designed with a separate center insert pin. This allows you to easily paint the body (e.g., gloss black) and the center insert (e.g., chrome/silver) separately without the hassle of masking tape!
• Metal Hardware Integration: Uses a standard metal hex nut (files for both M4 and M5 nut sizes are included) rather than printed threads, ensuring maximum durability and torque resistance.
• Heavy Duty: Designed to be printed with 100% infill to withstand heavy pulling and twisting forces.

Hardware Required:

• 1x M4 or M5 Hex Nut (depending on the version you print)
• Two-part epoxy or strong CA glue (for securing the nut and the center insert)

Recommended Print Settings:

• Material: PETG, ABS, or ASA (Highly recommended if used in automotive interiors to withstand high cabin temperatures).
• Layer Height: 0.12mm (Fine). This is crucial to minimize layer lines on the tapered body and make sanding much easier.
• Infill: 100% Rectilinear. You want this part to be a solid block of plastic for maximum compression and pulling strength.
• Supports: Normal (On build plate only). Required for the overhang on the bottom edge of the knurling.

Assembly & Finishing Guide (For the ultimate NOS Bakelite look):

1. Prep: Sand the main knob body smooth to remove any remaining layer lines.
2. Paint: Paint the main body with a Gloss Black finish. Paint the center insert pin separately with a Chrome or Silver finish.
3. Insert the Nut: Apply a small amount of epoxy into the hexagonal cavity at the bottom of the knob and press the M4/M5 metal nut into place. Let it cure.
4. Final Assembly: Glue the chrome center pin into the top cavity of the knob.
5. Clear Coat (Optional): If applying a clear coat, test it on a scrap painted piece first. Some clear coats can dull the mirror effect of chrome paints. If this happens, only clear coat the black body before inserting the chrome pin.

Happy printing and restoring! If you use this on a cool project, please share a make—I'd love to see where this classic knob ends up!