M16 - Belt Glitch
M16 - Belt Glitch: Subframes such as this were common before the RA belt was tightened in November, 2008. One of the"teeth" apparently would slip out of the track on one side of the motor gear that drove the worm gear. Depending on the declination, this would cause the guide star to leave the PHD guide square and the telescope would stop tracking. In this case, the glitch left the star "still in the box" and it took three corrective steps to get back on track. While this was going on, we tended to limit exposures to 3 minutes or less, as this allowed the best combination of long vs. usable exposures.
Date: November 2008