All worm wheel bearings inside NOTCam were exchanged in Nov-2007 during the preparation for the change of PCB and detector array (see above) following our preventive strategy of exchanging them every 2 years. None of the bearings were worn. This was also noticed the previous time (Nov-2005). Since this is a procedure that involves risks, we should re-consider whether the exchange should be done every 3 or 4 years, rather than every 2nd year. The first estimate was based on a very busy use of NOTCam, including the first test year, and without the ability to initialize one wheel at a time. Currently the wheels are turned less than before.