Celestron Starsense issue?

[Cashshadow]

Good Evening everyone,

 

I recently purchased a Celestron Starsense to use with my Nexstar 8SE. I drove a few hours away from the city and set everything up and the alignment worked perfectly - I calibrated it (which is recommended for the first time use) and was enjoying ooking at M13, M31, M57 and a few planets. About an hour in, I wanted to take a look at Uranus and while it was moving to its location, the telescope turned almost vertical and the star diagonal hit the mount.  I was worried about it potentially damaging the telescope so I turned it off and tried to realign it. Ever since I did that, I've had absolutely no luck aligning the telescope. I've constantly reset the telescope to horizontal position but all it does when I attempt to align it is either start looking at the ground, or start looking almost vertically in the sky again.

I took it home and updated the firmware on the controller and camera to the newest firmware and recently went to the park to try and see if that would fix it but here I am still with no luck. The optical tube was still pointed almost vertically and even though it gave me the "alignment complete" on the controller, it was completely out of whack.

 

Any ideas or recommendations on what to do?

 

I've double checked my time, date, DST and location numerous times on the handheld and they're all accurate.

[Starwatcher2001]

Hi, and welcome aboard.

Sounds pretty weird to me. Let me suggest some obvious stuff you may have tried to see if you've missed anything or give you ideas.

Does your 8SE still work correctly with the old "non-StarSense" handset?  If you do a three-star alignment, does it consistently find objects correctly? If that's the case, we can probably eliminate mechanical issues on the scope itself. I had a problem whereby I wasn't tightening the alt clutch quite tight enough and it was slipping slightly throughout a session.

Presume you're starting off with the tube reasonably level? I use a bubble level and also point mine South, but I don't think that matters. Also remember to take the cap off the camera (been there, done that). Since covered the cap in bright tape to remind me. Doing the automatic StarSense align, it should be moving to 3-4 different areas of the sky, stopping, taking a shot, then plate solving. Does it seem to be doing all this stuff (or at least going through the motions) before it declares "alignment complete" ?

When you updated the firmware, I think it's likely cleared out any user info... including the camera calibration!  I think you only need to recalibrate the camera offset if you use the camera on a different scope, mount it in a different position, reload the software, or do a full reset.

When you drove some hours away, did you use the location of the new place you were observing, or leave it set to home?  Might explain why it was off, but I can't think why it would look downwards.

If you've got WiFi on your scope, it's worth trying with the SkySafari or SkyPortal applications. I know it's an extra link in the chain, but it does have two advantages: it takes location and time from your tablet or phone, removing any ambiguity, and I find the diagnostic messages are better. It's easier to see what's going on.

I don't know what the clearance is like on the SE8, but on the 9.25, I move the tube as far forward as it will go when setting up. That gives adequate clearance between the diagonal and mount, even at the zenith. If you can't get that clearance for some reason, there's an option on the handset that you can use to prevent the scope attempting to go above a specific angle: Menu | Telescope | Setup | Slew Limits. That at least might save you diving for the off-switch.

Good luck. If none of this helps, come back and we'll scratch heads a bit more.

 

[Cosmic Geoff]

Good advice above. The diagonal should not hit the mount if the 'scope points vertically up. The scope should be as far forward (or up) as it will go in the clamp - it is not meant to 'balance'.

Starsense alignment is meant to start with the scope pointed in an index direction - I use horizontal due south.

I have found that a poor connection at the power inlet on the mount will cause mount misbehavior of the kind you describe.   With poor sky conditions in the form of bright sky I have found that the controller can give an alignment successful message despite pointing in completely the wrong direction.  It is less aftected by scattered clouds.

You should also re-check the dummy stuff such as lat/long location, time zone, etc.

Updating the firmware never fixes this kind of issue.  But the Starsense should be updated to the latest issue as you have done, to fix more subtle issues (always read the small print).

[Cashshadow]

Thank you both for the replies.

I did align the 8SE with the default hand controller before and it did work properly. I am also starting the alignment with the telescope level - I did not point it south but I will give that a shot. I made sure the camera cap was off the Starsense as well - I did leave it on the first time I ever used it but that was before the Starsense was properly aligned.

Someone else suggested to update the Firmware which I did and I definitely made sure to triple check that the time and location were absolutely accurate.  When I drove to the cottage a few hours away, that was the first time I ever used Starsense and I did select a different location on the controller that was much closer to where I was rather than my home town.

I did have space to move the optical tube of the telescope a bit further up which doesn't allow the star diagonal to touch the mount now even when it's vertical - thank you for that.

I will try again tonight and aim it due south before I start the alignment. I have a small feeling that it could be the batteries I was using are starting to die off due to the cold weather so I replaced the batteries a few minutes ago and will give it a go. When I first had the successful alignment, I did have a fresh set of batteries inside the scope - I really hope it's something as small as that.

Thank you both again, I will update tonight with the results.

 

Edit: It was the damn batteries all along! I replaced them and everything worked perfectly! Looks like I'll need to purchase a rechargeable battery tank/pack to carry around if anyone has any recommendations.

Edited September 22, 2020 by Cashshadow

[Starwatcher2001]

Fantastic. I'm glad you've sussed it out. Thanks for letting us know what the answer was, your post may help other people in the future with the same problem. 😀

Clear skies and enjoy your scope.

 

[Gfamily]

14 hours ago, Cashshadow said:

Edit: It was the damn batteries all along! I replaced them and everything worked perfectly! Looks like I'll need to purchase a rechargeable battery tank/pack to carry around if anyone has any recommendations.

For the last 3 or 4 years I've used a leisure battery for my scopes, but earlier this year I bought a Celestron Lithium power pack that works really well with my AZ GTi mount (it is small and lightweight and straps onto the central column).

https://www.rothervalleyoptics.co.uk/celestron-powertank-lithium-lt-61ah.html