moderated Re: Newbie question re: APPM

Roland Christen

You would be making a mapping run all the way from the "correct" side thru the meridian to the "upside down" side. And you would do this on both sides of the meridian. Then the model will work when you are upside down on either side.

Best practices would be to start your scope pointing east with counterweight up and let your scope track all night thru the meridian. That is the best way to avoid any pier crashes because you will see any potential obstruction issues at the very start of the session. If there are none at the beginning, there will never be any afterwards.


-----Original Message-----
From: dcraft34@... <dcraft34@...>
Sent: Fri, Apr 30, 2021 4:37 am
Subject: [ap-gto] Newbie question re: APPM

I don’t yet have my AP1100 (comes soon).  I’ve never used a german equatorial mount, so I’m clearly getting ahead of myself.  I hope to use the APPM tracking model with APCC for photometry with a Meade 14 inch with mirror lock, and F5 giving 1.17 arcSec / pixel, and weighing roughly 90# plus counterweights.

I hope to start all of my photometry runs counterweight up and track well past the meridian.

If I correctly understand the APPM point mapping process, most of the mapping points will be derived with the mount in the more normal, counterweight down, configuration.  Is it reasonable for me to expect the tracking model to perform acceptably (no guiding needed) if the system in actual use is counterweight up but the APPM points were established using the counterweight down configuration?  I’m assuming some mechanical aspects of this OTA are imperfect and this question cannot be answered with certainty but I hope to deterine if my expectations are highly unlikely to be realized, or alternatively, that I have some reasonable probability of success if the mechanicals are stable.

Or has my mind made a pretzel shape of a simple situation?  (I’m not visualizing these mount operations with clarity yet- my first few hours of mount operation will teach me much.)

Thanks,  Dave

Roland Christen

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