I had my AP rotary drive out in the cockpit the other day to gain access for a different project. While looking at the unit I gave the output sprocket a nice spine by hand and I was surprised at how rough it sounded (and felt). When I came home I did a quick internet search on the AP and one of the items that popped up the most was comments on the brushes. Not knowing anything about the drive assembly, and not getting any info from Raymarine, I thought the sound I was hearing might be the brushes (or damaged brushes) in the drive motor. Long story short is I disassembled the unit and found the brushes were in very good condition after 14,000 KN of sailing and at least 90% of that with the AP engaged. I found that the noise I heard was the magnetic clutch slightly dragging on the gear case because it was not fully disengaging when it was de-energized. After taking everything apart and putting it back together the clutch retracted properly however I am not sure why it was malfunctioning in the first place. All in all the unit was in very good condition considering the mileage and vintage (1993). I have attached PDF file showing photos of the disassembly and my comments of the findings for anyone who is interested in what these look like inside.
Merry Christmas and Happy New Year!
Frank
Merry Christmas and Happy New Year!
Frank
