• Mild Steel

  • Chromoly Steel

    • Easy to work with

    • Relatively inexpensive ($4/foot)

    • Light weight

    • Can be easily changed/modified

    • Readily accessible. Comes in a large variety of sizes and wall thicknesses


  • Aluminum: Very stiff for its weight

  • Harder to weld

  • Needs more material to resist fatigue

  • Can be difficult to repair


  • Light

  • Strong (but not stiff)

  • Absorbs shock

  • Hard to weld

  • Expensive

  • Limited sizes

Brushless Electric Motors

  • Very efficient

  • More expensive

  • Controller is more difficult to wire

Brushed Electric Motors

  • Inexpensive

  • Lower overall efficiency

  • Controller is inexpensive and easy to wire


  • Choose carefully

  • Batteries are one of the areas where you get what you pay for.

  • Decisions to make:

    • What voltage does your car run at?

    • Higher voltage means lower current.

    • How much weight can you carry?

    • How much energy can you get at that weight?

    • Can your solar panels recharge the battery pack?

    • Is it a road race or a track race?

    • The 5 kilowatt kilowatt‐hour rule kw‐h = Amp‐hours x Voltage (at the 20 hour discharge rate)

      • Example: Four 12 volt, 84 amp‐hour batteries batteries in series 84ah x 48 v = 4032 watt‐hours or 4.032 kilowatt‐hours