O Gauge Powered Truck Version 2

This is an O-gauge powered truck designed for custom 3D-printed O-gauge locomotives. It is intended for use with 1:48 scale locomotives approximately 322 mm long, 68 mm wide, and 95 mm tall. The design uses commonly available motors and bearings, making it well-suited for hobbyists building fully functional custom locomotives.

This second iteration removes any material extending beyond the axle wells, allowing the truck to be mounted as close to the coupler on the car body as possible for more realistic placement. The wheel profile has also been revised with a much more aggressive taper, improving the truck’s ability to navigate tight curves such as O36 track. The design has been tested on off-the-shelf O-gauge switches and operates reliably.

Truck Dimensions

• Overall height: ~30.5 mm (to bottom of locomotive body)
• Width: 55.5 mm
• Length: 68.5 mm

Body Mount

• Body ring through-hole: 52 mm
  • Designed to fit a 52 mm body opening perfectly

Wheel Specifications

• Scale: ~1:48
• Wheel tread diameter:
  • 23mm at the tire
  • Sharp Tapers to 16 mm
• Wheel thickness: 8 mm
• Wheel bore: 7.2 mm

Flange

• Flange diameter: 27 mm
• Thickness:
  • .80 mm at the flange
  • Tapers to 1.25 mm at the tire

Axle Specifications

• Axle diameter: 8 mm
• Axle length: 55.5 mm
• Distance between wheel flanges: 27.5 mm

Stepped Axle Features

• Wheel mount step:
  • 7 mm diameter
  • 9 mm long
• Bearing step:
  • 6 mm diameter
  • 5 mm long

Drive System

• Gear train:
  • Two 12 mm, 12-tooth gears
  • One 34 mm, 34-tooth gear
• Gear bore: 8.2 mm

Bearings

• Type: 6 × 10 × 3 mm ball bearings
  • 6 mm ID × 10 mm OD × 3 mm thick
• Quantity: 6 bearings per truck

Hardware

• M3 25mm long x 2
• M3 10 mm long x 3

Motor

• Motor type: TT motor
• These motors are widely available online and commonly used in hobby and robotics applications.