Why is my goto not accurate after drfit alignment?

[Robbie]

Ive had mine about 8 months so maybe yours is much better but it is better to have the gear to double check
Best of luck its all a learning curve but things get easier all the time.

[Barrykgerdes]

When I poured my slab I also marked the NS line but I did mine using the house plans on the computer. I knew the line of the boundary fences and used trigonometry to make an obtuse angle triangle where the long side ran due north and south right through the centre of the pier.

However when I set up the wedge I found the true 90 degree point of the OTA then adjsted the wedge til I could frame the south pole in a 26mm eyepiece because I already knew how to find it and what it looked like in a 26 mm eyepiece.

I never bothered with a drift alignment.

Barry

[merlin8r]

One thing that I don't think has been mentioned yet: Once you have completed your drift alignment and are satisfied with your polar alignment, you will need to switch of your scope, and run the auto align again.
This is because while you have been making the adjustments to the wedge, you have also been changing the location of all the stars relative to the scope. It doesn't know where they are anymore!

[Barrykgerdes]

Originally Posted by merlin8r

One thing that I don't think has been mentioned yet: Once you have completed your drift alignment and are satisfied with your polar alignment, you will need to switch of your scope, and run the auto align again.
This is because while you have been making the adjustments to the wedge, you have also been changing the location of all the stars relative to the scope. It doesn't know where they are anymore!

Actually the LX200GPs knows where all the stars are as soon as it is turned on what it doesn't know is date/time and location which it needs to get from the satellite, nor does it know its start up atitude. If your polar alignment is OK following a successfully drift alignment its attitude will be known and all it needs is to get a GPS fix and sync on a star. (ever more)

If you have a LX200 classic on an accurately aligned polar wedge it will know date/time and location from its internal clock and memory and will be tracking as soon as it is turned on. All it needs is to sync on a star. No other alignment is necessary. (ever more).

I know a lot of people don't believe this but think about it, try it and find out for yourself. Further when you understand fully how the telescope works there are lots of tricks to cut alignment in the field down to a couple of simple routines that can avoid long set up procedures and have you operational in minutes.

Barry

[merlin8r]

This is true.

My point however was that if you did a two star alignment, then drift aligned, your 2 star alignment was now incorrect.

[Barrykgerdes]

Originally Posted by merlin8r

This is true.

My point however was that if you did a two star alignment, then drift aligned, your 2 star alignment was now incorrect.

If your first alignment was an accurate two star alignment it will have established the attitude of the telescope as in the alt/azm mode as if it is in fact polar aligned and a drift alignment would have shown this to be correct.

In establishing the same atitude by drift alignment it should have now positioned the azimuth/RA axis passing through the poles as in a polar alignment exactly the same. From here there is nothing to be gained by doing the alignment again just ensure the telescope is in polar mode then do a goto and sync on a star. The scope will then be aligned. If there is a discrepancy between the methods the problem is not the alignment method but the mechanics of the scope.

The problem that most people have is that the telescope axes are not orthogonal. In this case you will never get a stable alignment. The so called two star alignment you want to do will seek to put the scope pack to where you started before the drift alignment and if you try a drift alignment it will have moved and need to be done again. You will be continually chasing your tail.

When I have "supercharged" and orthogonal aligned Paul's LX200 ask him how is alignments work. He will have his pier and permanent wedge spot on and his gotos will be excellent. Not being able to see the south celestial pole will not be a problem.

Baz