Star Adventure Pro, polar aligned but still get trails???

[GCG-Observatory]

Just bought a second hand Star Adventurer Pro, and having become aquatinted with it over a few nights, balancing and making sure I am correctly polar aligned, I still find that I am getting star trails on 10-20 second exposures on a 85mm lens. Over the course of 70 exposures, my subject will drift out of view. I check my polar alignment before, during and after and it is spot on. I am totally flummoxed as to why this thing doesn't seem to track. It has new batteries, and I have no warning LED lights. I have set it to Star on the dial and N on the S, Time-lapse, N switch.

Has anyone any ideas as to what my issue is here?

Thanks

 

[Jonk]

My first thought is - have you tightened up the clutch?

[david_taurus83]

Has the polar scope been calibrated? The reticle isn't loose?

[Davey-T]

Best stick a laser pointer on it and run it indoors for a sidereal day test.

Dave

Edited February 17, 2020 by Davey-T

[GCG-Observatory]

56 minutes ago, Jonk said:

My first thought is - have you tightened up the clutch?

Hi, yes I have, sometimes too tight, (so much I need to realign after trying to loose it) so I don't think that's the issue.

 

[GCG-Observatory]

21 minutes ago, Davey-T said:

Best stick a laser pointer on it and run it indoors for a sidereal day test.

Dave

I might have to try that

 

[Davey-T]

Just now, GCG-Observatory said:

I might have to try that

 

The first Star Adventurer I had was running slow and produced trailed stars in 30 secs with the Canon kit lens.

The replacement can easily do 15 minutes with a 14mm lens without particularly good PA.

Dave

[GCG-Observatory]

Are these things known for not tracking due to age, mechanical wear etc?

 

[Jonk]

Check the adjustment screw underneath the main body, if it’s too tight, the gears may not turn.

When you move the main switch to track, can you hear it whirring?

It could be the switch or loose connection inside.

[GCG-Observatory]

2 hours ago, Jonk said:

Check the adjustment screw underneath the main body, if it’s too tight, the gears may not turn.

When you move the main switch to track, can you hear it whirring?

It could be the switch or loose connection inside.

Which adjustment screw do you mean? Struggling to see one? Do you mean the clutch?

Yes I can hear it whirring and an occasional tick, which speeds up according to what speed setting its on

UPDATE

Yes finally found the adjustment screw, its an allen key style bolt, pushes down on the cog mechanism which which adjusts the tension between that and the biggest cog wheel. Thanks again, that was useful as it helped me when i finally found out the problem. See update below

 

 

Edited February 18, 2020 by GCG-Observatory

[happy-kat]

I am not suggesting  you open it up but you might find this interesting.https://stargazerslounge.com/topic/275823-inside-a-star-adventurer-mount/?tab=comments#comment-3020725

[GCG-Observatory]

1 minute ago, happy-kat said:

I am not suggesting  you open it up but you might find this interesting.https://stargazerslounge.com/topic/275823-inside-a-star-adventurer-mount/?tab=comments#comment-3020725

Yes, I did see that, and I have opened it up. Can see the cogs turning, but it doesn't seem to be turning the dovetail etc. I have put a small white mark under the dovetail assembly and a corresponding mark on the clutch area. Left it running on 12X speed and not an inkling of movement even an hour or 2 later

[GCG-Observatory]

UPDATE

I found the issue. Took the cover off to reveal the cogs, and could see that the motor was hanging loose. Then discovered that there was a screw loose by the cogs, and that it was the screw that must hold the motor into the cog housing. Fished it out, tightened it up, put it all back together and ran a test. Now tracking and making a soft whirring sound, no ticking. Hopefully job done. Thanks for help everyone. Hopefully now I can actually get some tracked shots, as last three or four nights have been frustrating.

[Jonk]

I’ve done this before, and I’m sure I’m not the only one.. but check you’ve tightened the clutch in the correct direction as it will tighten up when at its ‘loosest’ if that makes sense.

All the clutch does is pull the RA disc tight onto the brass worm wheel.

 

[Davey-T]

2 minutes ago, GCG-Observatory said:

I found the issue. Took the cover off to reveal the cogs, and could see that the motor was hanging loose. Then discovered that there was a screw loose by the cogs, and that it was the screw that must hold the motor into the cog housing. Fished it out, tightened it up, put it all back together and ran a test. Now tracking and making a soft whirring sound, no ticking. Hopefully job done. Thanks for help everyone. Hopefully now I can actually get some tracked shots, as last three or four nights have been frustrating.

Well done, I wonder if the last owner had the same problem or just didn't realise.

Dave

[GCG-Observatory]

Just now, Davey-T said:

Well done, I wonder if the last owner had the same problem or just didn't realise.

Dave

I contacted him and he said he didn't when he last used it in December. He did say he had the ticking though, so probably had the issue, as the cogs were not catching correctly as the whole tension was out, due to the motor being loose. Main thing is I have managed to sort it hopefully, and if anyone else has the same issue will be able to fix it now more easily.

[Jonk]

This would be a good candidate for a belt mod if anyone cares to give it a try?