Problem Found, maybe fixed
April 19th, 2009
It looks like the issues last night were caused by the RA motor pushing itself away from the RA drive shaft. The motor and shaft run parallel and are connected by a pair of gears wheels. The RA motor is held in place against it’s mounting plate by four screws but there is a small amount of play to allow the two gears to be properly meshed.
It seems these screws were to loose and possibly the RA axis was to tight which has allowed the torque of the motor to push itself away from the RA shaft. A real pain to be honest which would explain the dotting effect seen in the second picture below where the gear wheels are not in contact all the time so you end up with dots where it’s tracking and a dash where it’s not.
This morning I have removed the RA motor and re-adjusted the the RA shaft worm mesh, I’ve reduced backlash on the mesh and it now turns by hand. It still feels a little tight so maybe I need to dismantle it and replace the greece at some point. I’ve replaced the screws holding the RA motor in place and hopefully have the gears meshed a little better now.
The MET office tells me it should be clear tonight, so we shall find out then if my work have made the required difference.
