The following instructions should be sufficient to build a simple soapbox car with

1. a simple steering system for the mobile front axle and
2. a symmetric braking system.

Main ideas:

1. Use a transport cart wheel, remove the wheel put in a plank, attach axle [Example for transport cart wheel]
2. Use steering rod with simple pulley system to move the front axle [Instructions, Video with German explanations]
   Note: Use some pulleys or hooks to re-direct pull on the string to the same plane in which the axle is turning.
3. Symmetric braking system using rail system to put equal pressure on both wheel
4. Improvise based on available parts at home (eg construction wood, screws, nuts) and at local hardware store

Tools:

1. Electric drill to create holes in wood and metal with drill bits (8mm)
2. Hand saw to cut wood and metal (eg screws/rods which are too long).
3. Screwdrivers, electric screwdriver and bits as needed
4. Knife

Main Parts:

• 1 x  Main wooden plank
•  a few boards
• somethings which can be used as a seat
• 2 x axles (80 to 100cm, cut as you like)
• 4 x wheels + 1 x wheel as steering wheel
• 1 x threaded rod (Gewindestange) for steering rod, M12 diameter, 1-2m long
• 1m strong metal bar (for braking system)
• 1m thin metal rods as rails (for braking system) and tranmission, cut as needed
• about 10x set rings (Stellringe)
• about 10x pillow block bearing (Stehlager)
• 4x right ankle irons (foot rests, stabilizers)
• 2m strings
• various wood and metal screws with nuts

Fotos:

Figure 1: 12 man-hour version

 

Figure 2: 8 man-hour version