How to make a computer fan spin in both directions.

Hi everyone,

I\'m building a boat for a uni project that is propelled by two computer fans. The fans are controlled by an Arduino Uno and Motor Shield. However, the fans only spin in one direction...and don\'t spin at all if the current is reversed. I need the fans to be able to spin in both directions so that the boat is able to reverse when it senses an object in front of it.

I have read a little bit about the hall sensor, and I was wondering if it can be removed or modified in anyway to allow the motor to work in both directions i.e. when the current is reversed.

Thanks,

Tim

PC fans are brushless motors with a small controller embedded in them. It is going to be hard to impossible for you to hack.

Hi, thanks for the reply. Yeah, I took one apart and saw the little controller. I don\'t know how it works though...but there has to be some way to make it spin in both directions, just like normal brushless motors can when you switch the wires around.

You would need a brush less controller to replace the one in the fan.

Just replace the fan with a brushed version and all will work.