Having an issue with my goto the last few nights

[StarDuke82]

The past two nights whenever I use my goto on my Celestron Evo 9.25” to look at something high on the in the sky like the moon has been lately if I want to use it to goto say venus or slew to a star it wants to roll backwards, I mean to say past 90 degrees so that the eyepiece begins to rotate under the scope the first time it did this it had rotated almost 20 degrees before I caught it and my scope locked up and I had to take it in for the night, luckily I was able to get it unlocked with the hand controller. I took it out again tonight first time since it happened and everything was working fine until I used goto to the moon and then I decided to goto back to venus because some clouds moved in and once again it decided to rotate backwards. I just got it back from celestron for repair of a burnt out motor control board and I would hate to send it back again and have to get out my 6 inch Newtonian again for a month or more, anybody got any thoughts as to what is going on? 

[Carbon Brush]

I think the first task is to get a better idea of the circumstances to produce the fault.

No questions about power supply as you have doubtless checked this already.

Set up indoors in daylight. Run your stellarium or whatever on a separate device. Align the scope then tell it find targets. Using a compass and angle gauge is going to about the right places? Does fail in one hemisphere? Does it fail at particular altitudes?

Much better than losing a clear night to fault identification.

David.

[michael8554]

Hi David

If I understand your message correctly,  on the first night it failed on a Goto the moon ?

Then the next night it went to the moon okay ?

But then failed on a GoTo Venus ?

To me this means your Star Alignments worked both nights ?

But subsequent GoTo's to planets were flakey ?

You say it rotated "Backwards", Venus is about 90 degrees to the west of the moon, did it move in that direction ?

Michael

 

Edited May 1, 2023 by michael8554

[Cosmic Geoff]

I found that my Celestron CPC800 would occasionally malfunction when directed via GoTo to near the zenith (80 to 90 deg altitude).  Instead of slewing to target, it would just keep moving slowly past the 90 deg altitude.  I could regain control by stopping it with the handset and redirecting it somewhere else.  I never did find out what the problem was.

[StarDuke82]

22 hours ago, Carbon Brush said:

I think the first task is to get a better idea of the circumstances to produce the fault.

No questions about power supply as you have doubtless checked this already.

Set up indoors in daylight. Run your stellarium or whatever on a separate device. Align the scope then tell it find targets. Using a compass and angle gauge is going to about the right places? Does fail in one hemisphere? Does it fail at particular altitudes?

Much better than losing a clear night to fault identification.

David.

I took out again tonight and decided to used the Starsense to do an auto alignment, I then used my finderscope mounted opposite to verify it was properly aligned and recalibrated it. Then began issuing goto commands and it worked flawlessly throughout the night Moon, Venus, Beatleguese, Pollux, Arturus and back with no problems I don’t want to jinx it but it may have just needed to be recalibrated again.

[StarDuke82]

21 hours ago, michael8554 said:

Hi David

If I understand your message correctly,  on the first night it failed on a Goto the moon ?

Then the next night it went to the moon okay ?

But then failed on a GoTo Venus ?

To me this means your Star Alignments worked both nights ?

But subsequent GoTo's to planets were flakey ?

You say it rotated "Backwards", Venus is about 90 degrees to the west of the moon, did it move in that direction ?

Michael

 

Yes it rotated backwards to the west as in the OTA rotated corrector plate up whilst the eyepiece/Star diagonal passed under barely clearing the mount if it had continued to rotate.  I initially tried to unlock the clutches when I couldn’t get the scope to respond after I got it to stop but the alt clutch was locked tight. My main concern with rotating that far backwards is damage to the worm gears, I’m not sure if it can strip them out or not. However I took my scope out tonight and it seems that the problem has been resolved 🤞🏻

[StarDuke82]

20 hours ago, Cosmic Geoff said:

I found that my Celestron CPC800 would occasionally malfunction when directed via GoTo to near the zenith (80 to 90 deg altitude).  Instead of slewing to target, it would just keep moving slowly past the 90 deg altitude.  I could regain control by stopping it with the handset and redirecting it somewhere else.  I never did find out what the problem was.

Sounds exactly like what mine has been doing maybe it’s a software issue, and if Celestron is aware of the problem? Seems like the scope should only be allowed to move a maximum of 90 degrees on the alt axis and no further being able to move past it makes me think if one left there scope to goto an object and went inside for something while it did and this issue occurred could it rotate a full 360 degrees and if it can damage the gears in the mount?