Fans

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This page is incomplete. It does not cover all important aspects of this subject. Please keep this in mind when reading the page and add relevant information if possible.
A DC hair dryer fan
Fans can be used to mechanically blow objects or to heat/cool objects using the supplied air. There are a wide variety of fans that can be used for different events, such as MagLev, but some fans are not legal, depending on the allowed electronics.


Fan types

Box or Axial Flow Fans

  • Brushless Fans
    • The common computer fan is a brushless fan. These fans are driven by brushless motors, which rather than using mechanical switching to change which coils are energized and thereby generate the rotational motion, use integrated circuits and transistors. This allows for more precise speed control, but depending on the rules you are building under, such electronics may be illegal.
A DC brushless fan
Breakout of a DC brushless fan
  • Brushed Fans
    • Many axial flow fans are not brushless and are therefore legal every year that allows motors. The hairdryer fan featured in the description is an example of a brushed axial flow fan.

Centrifugal or Squirrel Cage Fans

Crossflow or Tangential Fans

Acquisition

Appliances

Fans in large appliances like vacuum cleaners are AC motors are therefore not useful. Smaller appliances are more likely to be using DC motors to power their fans, though in some cases you may have to remove a rectifier circuit from the motor terminals. Hair dryers are usually a good bet, but some use AC motors. Dust busters and other similar rechargeable devices will be using DC fans.

A DC hair dryer fan
An AC hair dryer fan

Purchasing

All electronics surplus retailers will carry fans of various types. Radioshack and other similar stores will have some fans, but watch out for brushless fans if your rules prohibit such electronics.