Quote:
Originally Posted by sheeny
G'Day Peter,
Be aware also of magnetic interference on your compass when setting up you scope. Your mount has steel in it, so it will affect your compass. I always walk about 3-5 metres away from my mount and shoot past it to check alignment. Watch out for other things that will affect your compass as well... cars, metal fences, power lines, steel frames buildings, steel sheds, etc.
Al.
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Hi Al, thanks for the compass advice, the needle moved around quite allot depending where I stood, so I have now marked a point for the rear tripod leg and a point 40 ft away pointing 169 degrees sth.
Quote:
Originally Posted by Screwdriverone
Hi Peter,
Yes, I agree, DONT trust the scales.
My Eq2 Skywatcher mount was 6-8 degrees off in the altitude scale. When I was set correctly to Sydney's Latitude, I could not find the SCP.
What I did was to piggyback my binoculars onto the scope and find the SCP using them (and my document about it here helps you identify it) and then man handle the scope by pivoting the tripod on one leg and getting the SCP lined up with the binoculars and then making sure the finderscope and telescope point to the same place by adjusting altitude and direction to get it alll lined up.
Once I did all this, I could see the SCP triangle near Sigma Octanis and the tripod was in the correct spot. When checking the Altitude scale, I noticed it was on 40 degrees instead of 33.5 so it was about 6.5 degrees too low when set correctly.
Other members pointed this inaccuracy out to me so I thought I might pass on the favour. Subsequently when I took the scope and the mount to the supplier, they heated the altitude scale with a heat gun, pulled it off the scope and because it was set correctly, reinstalled it back on to the correct setting and all is fine now.
Moral to the story? Try to drift align and then it wont matter because part of the process involves setting this to correct errors. Or do as I do and place the scope at 168 degrees with a compass and then fine tune to the SCP by finderscope. This now takes me 1 minute to get my scope lined up accurately to the SCP for tracking.
This assumes that you can see the SCP stars as opposed to the drift method which does not need the SCP to be visible.
I hope this helps.
Chris |
Thanks Chris, I've read your instructions and will give them a go tomorrow night (weather permitting). Tonight I spent time essentially proving the mount markings and level are wrong and I'm now satisfied they are .....
The altitude scale is out by 6 degrees at least and, after lining the scope up using my new south line (marked in the back yard) I performed a 3 star alignment and successfully moved between a number of objects.
I didn't get time to check the drift align tonight but it certainly seemed to be tracking well.
