Help needed!! Eq6r mount accuracy on 3 star allign.

[Leewfc]

Hi hope everyone is safe and well? I'm in some desperate need of some help. I purchased my mount in June and due to the lack of clear nights I've not had many opportunities to use all of my new equipment fully. First few times I used my equipment I learnt how to balance my new mount and learnt the polar alignment process. Then I started to learn the 3 star alignment process and first few times the objects selected didn't appear to be far off. Just recently I've had 2 or 3 nights where I appear to be some distance from the selected object. I have tried doing a reset of the PAE data but still continue to be some distance from the selected targets even on the 3rd star alignment surely this isn't correct? I've rechecked my alignment process and looks good to me including the test to check object in centre of cross hairs rotate 180 and object remains slap bang central. only thing left for me to try next clear night is a full factory reset of hand controller but I'm getting really frustrated as you can imagine with wasting time setting up to not take many steps forward. Has anyone suffered similar issues? If so how did you overcome this. For example I selected Sirius the other night and ended up pointing halfway between Betelgeuse and Sirius on third alignment. I've also got an A to Z go to 200p synscan and when I first used this the accuracy was really good so I cant understand why I'm so far off with this newer equipment. Please any help or advice is massively appreciated. TIA 

[Davey-T]

Have you altered the time back from BST to GMT ?

Dave

[Leewfc]

12 minutes ago, Davey-T said:

Have you altered the time back from BST to GMT ?

Dave

I usually follow through the information on the hand controller and enter exactly what shows on my app on my phone Synscaninit 2.1. Would that cover that part or would I have to change elsewhere in settings? thanks

[symmetal]

Betelgeuse is 22 degrees from Sirius and a one hour error in the time setting on your handset puts you off by 15 degrees so Dave's suggestion looks a likely answer. 🙂

Alan

Edit Assuming you're in the UK and your location is input correctly you need Time Zone set to 0, and Daylight Saving set to No which I assume your SynscanInit is displaying.

Edited February 16, 2021 by symmetal

[Leewfc]

11 minutes ago, symmetal said:

Betelgeuse is 22 degrees from Sirius and a one hour error in the time setting on your handset puts you off by 15 degrees so Dave's suggestion looks a likely answer. 🙂

Alan

Edit Assuming you're in the UK and your location is input correctly you need Time Zone set to 0, and Daylight Saving set to No which I assume your SynscanInit is displaying.

Yes synscaninit shows the following. I've also popped the image of what the handset was showing the alignment details as.... once aligned it says alignment poor. I've tried everything relooked at the polar allignment to check that. I've re entered all the details into handset. My polar clock doesn't show exactly 0 and 6 top and bottom but I always put the dot exactly as shows on app I use. Dont know if the reticle makes much difference I was told not as long as I put the dot in correct spot as showed on app. Thanks everyone for your help

[symmetal]

Your Mel Maz display indicates that the polar alignment is over 1 degree out in azimuth which is about two thirds the diameter of the polar alignment circle. The circle is about 1.5 degrees in diameter. As you say the polar clock doesn't have to set with 0 at the top as long as you judge where Polaris would be on a clock face, if you assume the 0 is at the top and 6 is at the bottom. You've done the 180 degree rotation test and the object in the centre didn't move so your polar scope reticule is correctly aligned with the centre of the mount RA axis.

When you're accurately polar aligned you should be able to look through the polar scope and rotate the mount in RA and Polaris should stay on the polar reticule circle as the circle rotates. With a 1 degree azimuth error as you've indicated Polaris would shoot off the circle as soon as you rotate the mount RA axis just a little. It's worth checking that before you do a two or three star alignment to see where the problem lies. You can make small mount azi and alt adjustments while rotating the RA axis to try and get Polaris to stay closer to the circle if you wish. If Polaris stays on the circle while rotating RA then your polar alignment is very good and a one star alignment is all that's needed to have good gotos. The two star alignment corrects your gotos when you're not perfectly polar aligned.

Have you tried just a two star alignment. I've read reports where a three star alignment can seem to give worse results than a two star alignment for your Goto accuracy. The third star is to correct any cone error, (scope optical axis not parallel to RA axis), but it's normally fairly small in most setups and can be ignored to start with.  It may be worth using the handset Setup menu option to delete any stored alignment values, particularly cone error, as if you do a two star alignment after a three star alignment, I believe it asks if you want to apply stored cone error values.

Alan

[Jiggy 67]

I agree with @symmetal Many people will say that PA has little or no effect on GoTo accuracy. My experience is that it definitely does, the more accurate your PA the more accurate your pointing accuracy. Do you suffer from cone error? If not, or it is very small, do not do a 3rd star alignment, it serves no purpose 1 or 2 is enough. I would concentrate on PA if you are confident that all data inputted into the handset is correct. Also, are you starting from an accurate home position after PA ? Counterweight down, scope pointing North

[Leewfc]

2 hours ago, Jiggy 67 said:

I agree with @symmetal Many people will say that PA has little or no effect on GoTo accuracy. My experience is that it definitely does, the more accurate your PA the more accurate your pointing accuracy. Do you suffer from cone error? If not, or it is very small, do not do a 3rd star alignment, it serves no purpose 1 or 2 is enough. I would concentrate on PA if you are confident that all data inputted into the handset is correct. Also, are you starting from an accurate home position after PA ? Counterweight down, scope pointing North

I'll try the PA test with RA axis next time I'm out. Then I'll check the cone error. I'm going to also do a factory reset and update firmware if there's an update. Thanks for all your help. If anyone does have any more ideas please let me know so I can try everything in one clear night. 

[Leewfc]

7 hours ago, symmetal said:

Your Mel Maz display indicates that the polar alignment is over 1 degree out in azimuth which is about two thirds the diameter of the polar alignment circle. The circle is about 1.5 degrees in diameter. As you say the polar clock doesn't have to set with 0 at the top as long as you judge where Polaris would be on a clock face, if you assume the 0 is at the top and 6 is at the bottom. You've done the 180 degree rotation test and the object in the centre didn't move so your polar scope reticule is correctly aligned with the centre of the mount RA axis.

When you're accurately polar aligned you should be able to look through the polar scope and rotate the mount in RA and Polaris should stay on the polar reticule circle as the circle rotates. With a 1 degree azimuth error as you've indicated Polaris would shoot off the circle as soon as you rotate the mount RA axis just a little. It's worth checking that before you do a two or three star alignment to see where the problem lies. You can make small mount azi and alt adjustments while rotating the RA axis to try and get Polaris to stay closer to the circle if you wish. If Polaris stays on the circle while rotating RA then your polar alignment is very good and a one star alignment is all that's needed to have good gotos. The two star alignment corrects your gotos when you're not perfectly polar aligned.

Have you tried just a two star alignment. I've read reports where a three star alignment can seem to give worse results than a two star alignment for your Goto accuracy. The third star is to correct any cone error, (scope optical axis not parallel to RA axis), but it's normally fairly small in most setups and can be ignored to start with.  It may be worth using the handset Setup menu option to delete any stored alignment values, particularly cone error, as if you do a two star alignment after a three star alignment, I believe it asks if you want to apply stored cone error values.

Alan

Cheers Alan ill give that a go. So how is the best way to complete the RA test with polaris around the circle? 

[Neil H]

Hi I have the HEQ5pro and what I found is clear PAE do the 3 star alignment now go for an easy target once the mount tells you it's on target take a look if it's off press esc then utility find PAE training press enter it will ask you centre target once on target then press enter now go to another target and repeat PAE training , Now you should find it will be on target , I don't know why the mount over time starts to miss targets but PAE training will get it back 

Next time you polar align you stars should be very close but getting polar alignment as close as possible it does help 

Edited February 16, 2021 by Neil H

[symmetal]

2 hours ago, Leewfc said:

Cheers Alan ill give that a go. So how is the best way to complete the RA test with polaris around the circle? 

Just the same way as when you rotated the reticule through 180 degrees by rotating the RA axis, looking at a distant object during the day, to check the reticule was centre aligned on the RA axis. In this case, however, if you're polar aligned with the reticule centre over the NCP, when you rotate the RA axis, Polaris will rotate around the NCP following the line of the reticule circle as Polaris is around 45' away from the NCP.

It may be worth mentioning that another reason for poor goto performance can be the mount clutches slipping if not done up tight enough, or grease has worked it way onto the clutch plate. Also check the scope rotates freely in both axis, with the clutches disengaged and there aren't any tight spots as you rotate. If there are, it is possibly the backlash adjustment for that axis has been adjusted too close and the worm is binding on the main gear at that point.

Alan

[Skipper Billy]

Your signature doesn't give your location but your lat and long gives somewhere near University of Warwick / South West Coventry.

Does that sound about right ??? Incorrect Lat and Long can give spurious errors like the ones you describe.

[Leewfc]

2 hours ago, Skipper Billy said:

Your signature doesn't give your location but your lat and long gives somewhere near University of Warwick / South West Coventry.

Does that sound about right ??? Incorrect Lat and Long can give spurious errors like the ones you describe.

Im walsall in the west midlands Coventry is about an hour away from me. I've just used the ones given from my phones location which I guess would be correct? If not how would I check these accurately thanks 👍

[symmetal]

 

1 hour ago, Leewfc said:

Im walsall in the west midlands Coventry is about an hour away from me. I've just used the ones given from my phones location which I guess would be correct? If not how would I check these accurately thanks 👍

The phones GPS location should be fine, but if you want it accurately goto google maps, zoom in and right click over your house location. It will give your lat and long in decimal degrees as the first line of the popup info. You can convert that to DMS format here. 🙂

Alan

Edit: negative longtitude values as shown by google maps mean it's West of the Greenwich Meridian so you'd enter it as a positive DMS value but then add West.

Edited February 16, 2021 by symmetal

[Skipper Billy]

43 minutes ago, symmetal said:

Im walsall in the west midlands Coventry is about an hour away from me. I've just used the ones given from my phones location which I guess would be correct? If not how would I check these accurately thanks 👍

This might be the cause of the problem then - the Lat and Long you are using is pretty much Kenilworth Castle. 

 

[Zermelo]

1 hour ago, symmetal said:

You can convert that to DMS format here. 

If you click to display the lcoation details panel in Google Maps, it shows both formats.

For the OP's details:

[Leewfc]

57 minutes ago, Skipper Billy said:

This might be the cause of the problem then - the Lat and Long you are using is pretty much Kenilworth Castle. 

 

ill take a look at that thank you

[Leewfc]

Thanks for everyone's help. I run some updates on hand controller and mount gears and reset everything to factory settings. Checked polaris in centre test and rotated 180 degrees. Was perfectly centred didnt move a bit. I then did the moving polaris to circles and placed on centre track rotated and it stayed perfect. I polar alligned and re entered the details in controller and moved onto star alignment. Did the 2 star and everything was perfect so must have been a software issue or something in the data that reset cleared. Thanks again for everyone's help.