The Sinister Penguin is equipped with four thrusters. They are some of the best small size thrusters available for applications like the RoboSub competition. They work by using a Magnet array in the hub of the propeller which is driven by matching magnet array attached to drive motor. The set that we have utilizes a 6:1 planetary gear set. They are manufactured by Tecnadyne.

The Sinister Penguin uses four thrusters. Two amidships on the sides for forward and reverse propulsion. One is in the stern pointed vertically. This thruster is responsible for pitch control. Adjustments of its voltage can pitch the vehicle up and down. The final thruster is located near the vehicles center of buoyancy. It is responsible for depth control. 

This year the biggest change to the thrusters was the addition of a set of capacitors to act as an electrical buffer between the thrusters and the batteries. An initial sketch of the circuit is in the picture on the left.  In 2009 and 2010 the vehicle experienced an unexplained problem and the thrusters stopped working. The exact reason for the failure was never determined, but the manufacturers suggested that electrical spikes could have been the culprit. The thrusters have worked flawlessly so far this year.

While the team was at the competition in 2011 we added a constant offset to the thrusters. This bias was tuned in through experimentation. Initial tests indicated that a correction of approximately .3 volts in magnitude to the starboard thruster was enough to overcome inefficiencies throughout the thruster/propulsion system and even out unbalanced drag factors. This alteration needs more alterations and design work to be implemented more successfully on the 2012 Navy AUV.

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