Re: Exos 2 pmc 8 goto precision issue #EXOS2

Wes Mcdonald


In my experience, after aligning with Polemaster, my goto is best if I do not do any alignment.  That is, the polemaster gets your mechanical alignment just right.  If you are using iOS or windows then do a subsequent SYNC on a star after centering it using the LRUD buttons. If you have Android there is no SYNC button (correction is in work I believe).  I would use something near about 0 Dec and near meridian, but about any star will work.  That sync will take the home error out and leave you with a good alignment.  If you are doing a deep space space dim object that is invisible in your finder/red dot, do a sync on a nearby star and your go-to will we bang on.

If using Android you can do a pretty good sync, I think, manually.  After polemaster, point to a star near your object of interest.  Then break the clutches and manually center the star and reclamp the clutches.  Subsequent goto should be really good.  For this adjustment do not use the LRUD controls, do the manual adjustment.

Last thoughts, if you have a really bad cone angle your go-to performance after a sync will be best near the sync location and fall apart as you move away.  In that case just keep doing a sync near the object of interest on a star you can see (after you center it with the LRDU buttons or via the loose clutch method) and the subsequent goto to a nearby dim object will be very good.

So in summary, two ways outlined after doing a good physical alignment with a polemaster:

1.  Use the software SYNC button in Explorestars on a bright star after centering with the LRUD buttons or

2.  Perform a manual sync by centering a star in the eyepiece by loosening the RA and DEC clutches and manually centering it.


Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired

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