Vectrix Motor Encoder Sensor Issues

At the below link are some photos and a report on one way of cleaning dust off the Encoder Sensor without special tools:
VisforVoltage » Home » Forums » Electric Rides » Motorcycles and Large Scooters » Vectrix » Encodr and yellow wrench error message

http://visforvoltage.org/forum/6461-encodr-and-yellow-wrench-error-message

EDIT 2009-07-10: The above link is now a book page at: http://visforvoltage.org/book/ev-collaborative-hand-books/6972

This comes from the makers of the encoder!

Vectrix needed a feedback device for the brushless motor used to propel the scooter, which was easy to install, rugged, low cost, and utilizes heavier gauge wires with automotive grade interconnect. Vectrix chose the RENCO RE200 Kit Encoder to meet their requirements for this application.

http://www.globalspec.com/FeaturedProducts/Detail/renco/Case_Study_Vetrix_Maxi_Scooter/84190/1

Incremental rotary encoders have many applications in interfacing electronics to mechanical subsystems, but how do they really work? What should designers hone in on when selecting one? An encoder mechanics expert offers a perspective on how to sort through the different fabrication technologies, parameters, and choices.

http://www.smallformfactors.com/articles/id/?3039