Advice on drift aligning.

[batema (Mark)]

After purchasing our new Skywatcher ED 80 and HEQ5 mount this process has successfully attracted the first potential cyclone to the sunshine coast. In anticipation of fine weather a question on alignment.
When focusing on a star on the eastern horizon and adjusting the altitude to stop drifting, then swinging to above and adjusting only azimuth to stop drift then back to the eastern horizon and repeating the process for altitude.
My question is do you repeat this process adjusting only the altitude for the star on the horizon and only adjusting the azimuth for the star overhead until you have no movement or can you adjust both when viewing one object or will this be catastrophic. Thanks Mark.

[mill (Martin)]

Always adjust one at a time or it will make the other adjustment useless.

[matt]

Yep. As mill says, one at a time.

It is an iterative process, so you go from one to the other and back again, gradually refining your alignment to a point where you are happy with how long the star remains centred.

[ballaratdragons (Ken)]

Don't know what happened with my drift alignment 2 weeks ago.

I used the polarscope, and my laser on the SCP method. Checked it on the lappy for accuracy and it was lovely. All GoTo's were spot-on all over the sky, and no drift over 1/2 an hour with Autoguiding turned off.

Then I did a drift alignment.
It was sooooo close it wasn't funny, but I wanted to practice, so I moved the mount a smidge in both Alt and Az. Then after about 2 hours of verrrrrry fussy drift aligning, I once again had no drift for well over 20 mins

I re-started the whole 3 star alignment again. For the rest of the night it would not do accurate GoTo's and Autoguiding was chasing all the time. It was hell to image!
I re-did my original method and all GoTo's were spot-on again
I think I'll stick to my laser method and give the Drift aligning away

[OneOfOne (Trevor)]

Originally Posted by ballaratdragons

...Then I did a drift alignment.
It was sooooo close it wasn't funny, but I wanted to practice, so I moved the mount a smidge in both Alt and Az. ... For the rest of the night it would not do accurate GoTo's and Autoguiding was chasing all the time. It was hell to image!

Ken, surely you have heard of "if it ain't broke, don't fix it!"

[ballaratdragons (Ken)]

Originally Posted by OneOfOne

Ken, surely you have heard of "if it ain't broke, don't fix it!"

ummmm . . . yep

I should have left it alone

[mill (Martin)]

Breaking it and then fixing it is just fun
Just found another way of polar aligning.
Plonk the mount down let the gps update the time and do a two star alignment but instead of using the hand controller to get the first star in the middle, move the RA and DEC to center the star.
Then goto the second star and use the hand controller to center.
After having done this yesterday night my goto's are spot on, and that is in the middle of the envisage screen with the dsi.
I believe the dsi acts as an 6 or 8mm eye piece
M42 stayed in the middle of the dsi screen for hours and drifted over that time only about 1mm, this was with no autoguiding.
I know it might be hard to believe that it could be this easy.
I have asked others to try polar aligning this way today and will wait for the results.
Having the accurate time is a must, so gps is the best way to do it.
I even deliberately grossly misadjusted the mount ie:50 degrees east and 44 degrees latitude.
After the first star alignment the mount was all back on the right latitude of 37.78 degrees south and longitude of 145.38 east.
Maybe some others who read this might try this and report back.
If this works then you would be able to go anywhere and plonk the mount roughly south but level and find an star in the hand controller that is east or west low on the horizon and adjust the mount that way.

[ballaratdragons (Ken)]

Sounds too easy, Marty.

I'll have to try it

I don't have GPS, so I'll have to go by the nearest minute.

[robert.knox (Robert)]

Try having a look at the instructional video on the following web site....

Robert

http://www.andysshotglass.com/DriftAlignment.html

[JohnH]

Originally Posted by mill

Breaking it and then fixing it is just fun
Just found another way of polar aligning.

Mill I think you have discovered half of the iterative goto method...see here:

http://www.rogergroom.com/rogergroom...m.jsp?Item=343

PS It works!

[mill (Martin)]

Bugger! and i thought i was the first one to think about that
Some people are as smart as me