Polar Alignment on AZ-EQ6 not working...

phobos27 (Nick) · #1 30-06-2014, 09:12 PM

Over the last few weeks, whenever I have taken out my telescope I have set it up, done the 3 star alignment and then tried to do a polar alignment. It starts off fine and slews relatively close to the star so I move it with the keys. I then click enter and around two thirds of the time it will then keep slewing till it is facing the ground... I don't know if I am doing something wrong or it is the mount but I am definitely facing it south.

If someone could run me through how to do it or if you need more info i would be happy to give it to you.

AZ-EQ6 Mount with an 8" Newtonian on top.

Thankyou for your help!

glend (Glen) · #2 01-07-2014, 01:04 AM

Do you have the manual? It can be downloaded from the Skywatcher website. Perhaps an upgrade of the controller software might help, download that as well.

SimmoW (SIMON) · #3 01-07-2014, 07:44 AM

Thanks for raising, I've had a similar issue. My firmware is on v3.28, apparently a pretty stable version, I've googled and the latest 3.35 is not recommended?

I have heard that a new star alignment is required every time you do a PA. That may fix it. Annoying..

Dealy (Kev) · #4 01-07-2014, 08:37 AM

I've had the same problem as well. I stopped using the polar alignment function because it was doing my head in

I do a 2 star alignment, then when the mel & maz readings appear make adjustments. Then do another 2 star alignment. Normally I only need to do this 2 or 3 times and I'm within 10 minutes.

With my orion 50mm guide scope and phd I have near perfect tracking for 5-7 min subs.

Occasionally though I have to select different stars for the 2 star alignment or no matter what I do I can't reduce the error to below 10 minutes.

It can be very confusing.

rustigsmed (Russell) · #5 01-07-2014, 09:36 AM

hi guys,

nick i had a similiar issue with my eq8 pointing, upgrade the firmware to v3.35.

i believe you need to do the following:

first do a two star alignment.

then do a polar alignment - this is when you should use the mel maz errors. then repeat the polar alignment again.

cheers

Rusty

phobos27 (Nick) · #6 01-07-2014, 10:55 AM

Thanks Guys for all the suggestions!

I have not upgraded the software in my controller since I bought it so that may be the problem...

I will also try what Dealy said tonight because the weather is looking pretty good up here!

Quote:

Originally Posted by Dealy

I've had the same problem as well. I stopped using the polar alignment function because it was doing my head in

I do a 2 star alignment, then when the mel & maz readings appear make adjustments. Then do another 2 star alignment. Normally I only need to do this 2 or 3 times and I'm within 10 minutes.

With my orion 50mm guide scope and phd I have near perfect tracking for 5-7 min subs.

Occasionally though I have to select different stars for the 2 star alignment or no matter what I do I can't reduce the error to below 10 minutes.

It can be very confusing.

Also if you do use the Mel and Maz alignment then how do you know which one is which? I believe that Mel is the elevation and Maz is the azimuth. If the Mel says for instance +5 degrees, do i have to move it up 5 degrees to make it even or down 5 degrees. Also the same with the Maz. If it says +5 degrees do I have to move it east or west?

One last question... When you do a PA, do you have to do it with one of the stars you used in the initial alignment?

Thankyou for all your help guys! It has given me some new ideas to try tonight!

rustigsmed (Russell) · #7 01-07-2014, 11:12 AM

hi nick,

if you do the two star alignment - ignore the errors.
then do the polar alignment routine as listed in 11.3 - it explains it

better. and it will make sense when you do it. its good because you visually adjust the star to bring it into centre with the alt and az controls. you don't have to actually remember if its 'left' or 'right'.
http://www.skywatcher.com/downloads/...b_280313V3.pdf

cheers

rusty

SimmoW (SIMON) · #8 01-07-2014, 11:16 AM

yes, that's the advantage of that routine, no guessing.

But myself, the other night, when it slewed, it went a totally weird direction not correctable via the RA knobs! Only way to correct it was to use Altitude, which is incorrect? I do know my levelling was way off, would that cause such weird behaviour?

rustigsmed (Russell) · #9 01-07-2014, 11:22 AM

Quote:

Originally Posted by SimmoW

yes, that's the advantage of that routine, no guessing.

But myself, the other night, when it slewed, it went a totally weird direction not correctable via the RA knobs! Only way to correct it was to use Altitude, which is incorrect? I do know my levelling was way off, would that cause such weird behaviour?

i had the same problem with the original firmware, upgrade with v3.35

SimmoW (SIMON) · #10 01-07-2014, 11:30 AM

I'm gonna hug you if this works mate!

Eden (Brett) · #11 01-07-2014, 12:29 PM

Hi Nick,

Sorry to hear that you're having hassles with the PA routine.

I haven't encountered this specific issue but it's possible that upgrading to v3.35 will help, since Skywatcher made some modifications to how the PA routine works in that version. In v3.35, the PA routine is broken down into two steps -- one for altitude and one for azimuth, the mount slewing between each adjustment.

According to Skywatcher, this was done to improve the accuracy of the routine. There could be unspecified bugfixes included, however.

Some things to consider:

- After you adjust the altitude and/or azimuth of the mount during the PA routine, your 2 or 3 star alignment will no longer be accurate and your pointing accuracy will also be compromised. For this reason, I recommend powering off the mount and doing the star alignment again and if necessary, making additional PA adjustments until you are happy with the result.

- If your tripod/pier is not level, it will impact the accuracy if your star alignment and ultimately your PA. The bubble level on the mount is barely adequate and I would suggest using one from the hardware store. iPhones running iOS 7.1 also have an inclinometer built in which works very well.

- Unless you absolutely depend on it, disable the auxiliary encoder on the mount. This allows you to unlock the clutches on the mount and make manual adjustments to RA and Dec without losing your alignment. If you're not into the habit of doing this, disabling the auxiliary encoder will improve your pointing accuracy.

- You can simplify things a bit by performing a rough polar alignment on the very first alignment star. Start the 2 or 3 star alignment, let the mount slew to the first star and, instead of using the buttons on the hand controller to bring the star into view, adjust the altitude and azimuth. If you're not able to bring the star into view with the azimuth knobs, turn the whole mount around until you have plenty of extra movement available in each direction of the azimuth.

After doing that, if you cycle the power on the mount and start the alignment process again, you should find that the first and subsequent stars should be visible in your eyepiece/camera when the mount slews to it.

phobos27 (Nick) · #12 01-07-2014, 12:56 PM

Thank you guys for all the help!!!

I will now upgrade my firmware on the controller so it can 'fix' this problem.

That manual was very helpful because mine didn't have as detailed instructions as that.

Also in the manual it says that you need to have the last two moves using the right and up keys... Was that always the case because that might be the reason mine was not working properly.

I don't know but I am looking forward to bringing it out tonight!

Thanks for all the help again!

Amaranthus (Barry) · #13 01-07-2014, 01:19 PM

Nick, I have upgraded to v3.35, but the PA routine did not work out for me. (It got me to within about a degree of the pole, but then just iterated me around that point, not getting any closer despite multiple attempts). I eventually gave up on this and used CCD drift alignment, which is superb.

Pointing accuracy for GOTO on the Synscan system for the AZ-EQ6 is critically dependent on a good choice of alignment stars, for alt-az mode. I haven't seen any advantage of 3- over 2-star, even though, theoretically, it should improve the situation.

raymo · #14 01-07-2014, 07:43 PM

The last two moves being right and up will give better Go To results, but will not cause major problems.
raymo

phobos27 (Nick) · #15 01-07-2014, 09:34 PM

I just wanted to let everyone know that everything is working and i have managed to get my scpoe within 40 seconds of south. I downloaded the firmware updat and also followed the manual step by step! This worked and i am very happy to be able to start Astrophotogrpahing again. There is only so much time one can dedicate on a freezing cold school night to try and get their telescope working!

I am very happy and am thankful for all the help everyone has given me! This is such a great commmunity and I feel so privileged to be apart of it! I am now photographing the Triffid Nebula so I will share the pics tomorrow!

Nick

rustigsmed (Russell) · #16 03-07-2014, 09:27 AM

Quote:

Originally Posted by phobos27

I just wanted to let everyone know that everything is working and i have managed to get my scpoe within 40 seconds of south. I downloaded the firmware updat and also followed the manual step by step! This worked and i am very happy to be able to start Astrophotogrpahing again. There is only so much time one can dedicate on a freezing cold school night to try and get their telescope working!

I am very happy and am thankful for all the help everyone has given me! This is such a great commmunity and I feel so privileged to be apart of it! I am now photographing the Triffid Nebula so I will share the pics tomorrow!

Nick

Good to hear Nick

thanks for posting your feedback too.
the triffid you posted was a great first light.

next on the list i think would be a coma corrector to take care of the peripheral stars. then down the track some autoguiding to lengthen the sub length. but you can get some really nice results @ 30 seconds so there isn't a rush to complicate the system further yet.

looking forward to seeing more

Rusty

phobos27 (Nick) · #17 03-07-2014, 10:29 PM

Quote:

Originally Posted by rustigsmed

Good to hear Nick

thanks for posting your feedback too.
the triffid you posted was a great first light.

next on the list i think would be a coma corrector to take care of the peripheral stars. then down the track some autoguiding to lengthen the sub length. but you can get some really nice results @ 30 seconds so there isn't a rush to complicate the system further yet.

looking forward to seeing more

Rusty

Thanks Rusty.

My problem is currently that i can do 5 minute exposures however, when i do, the image is overexposed because I live in the orange zone! I will try longer subs however next time I am out west!

Thanks for the feedback!