Re: Detaching Dec axis from RA axis on 1200 mount


Dale Ghent
 

On Jul 30, 2022, at 19:07, Mike Cadwell <mikecadwell@...> wrote:

Hello All,

Need some advice here.
My 1200 mount axes have been attached for about ten years, no oil or grease used (didn't read the manual thoroughly!).
Any suggestions on how to separate them without doing harm?
Also, what type of lubricant and how much should be used for reassembly?

1. Call AP and order a grease kit. It's cheap and has both types you'll need. You may also want to replace the delrin clutch plugs if your axis is rather stiff when unclutched. A baggie of those doesn't cost much, either. Depending on the age of your mount, there may be other things you want to consider. Older motors that might need the ESD protection board, A new/spare Y cable to have on hand, a fresh battery for your keypad, placing the RA axis clutch knobs with hex key set screws, etc. Call AP and George can help you figure out what you might want to do. Might as well do all you can while the patient's on the table.

2. Put the mount in Park 3, remove the OTA and stow any cables out of the way. Remove the motor Y cable and counterweights. Before you remove the CWs, stick a ring of painter's tape around the shaft to denote the upper and lower extent of the stack of CWs so you don't have to rediscover that later. You can choose to remove the CW shaft as well or leave it on, depending on how much you don't mind lifting later when you remove the dec axis.

3. Loosen the two large silver dovetail knobs on either side of the CW shaft. You can grab the saddle with one hand and the CW shaft with the other and pull up on the shaft. If the dovetail pins inside still catch, lower it back in place and unscrew the knobs some more. When the dovetail pins are sufficiently retracted, you can grab the CW shaft/bottom if the dec axes and pivot the entire dec axis up while also holding it securely by the saddle. Pivot it up from the bottom then lift it up and off the RA axis.

Remember to remove the OTA first, then the CWs. When you put things back together, CWs go on first followed by the OTA. You don't want to take the CWs off and have a loose clutch cause your OTA to violently rotate down into the pier or side of the mount.

/dale

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