What's going on with the tracking on my EQ5

[DaveGarland]

Could anyone please tell me what is going on with my tracking. I have an EQ5 GOTO. Basically my confusion is this. If say I point my scope at Mars and centre it in the eyepiece, it gradually wanders off. After about 15 mins it will wander right out of view. Now this doesn't really confuse me as I know that it's only turning over its motor at what it thinks is the right speed. What confuses me is that if I tell the control to look at Mars, it moves the scope so that it is once again looking directly at Mars! How so? If it knows Mars is in that position at that time, why isn't it tracking it?

Thought please folks?

[DaveGarland]

Ps. Yes I have checked I have it set to Sidereal Tracking.

[oldpink]

Sidereal is for stars tracking that may be your issue

[knobby]

I've always wondered if it was clever enough to realise that if you tell it to goto a planet if it would compensate knowing it was looking at... A planet? Or even the moon

[DaveGarland]

Ah I've made an error in my example. I picked Mars off the top of my head and of course is a planet not a star. But I get this problem with all objects.

[oldpink]

I've always wondered if it was clever enough to realise that if you tell it to goto a planet if it would compensate knowing it was looking at... A planet? Or even the moon

thats why I use EQMod to track rather than my handset

makes corrections easier when using Stellarium or CdC, which corrects when you use the sync function

the more you sync the better the tracking gets

last night I had 4 flips and the targets were very close each time needing only minor adjustments

[ronin]

Mars is presently (I believe) moving in retrograde, it is moving backwards. This is not a lot compared to the general sidereal movement but will account for some of the problem.

Think it started retrograde when at opposition then maintains this apparent wandering the wrong way for about 3 months, before starting to move "right".

[jambouk]

It sounds like your polar alignment needs to be better. The GOTO simply puts the scope into the target, the GOTO has nothing to do with tracking. Tracking is the responsibility of you to select "sidereal rate" in the handset, and also on how well you polar aligned the scope.

I'm not sure what your focal length is, but if the planet stays in view for 15 minutes, that means, in my mind anyway, your polar alignment is in the right ball park, but easily room to get it much tighter.

Do you have a polar scope?

Do a much tight alignment is likely to solve the issue.

Other considerations:

- is the scope well balanced?

Good luck

Jd

[ollypenrice]

Yes, I'm sure this is just your polar alignment. It goes back to Mars (or whatever other object you synched on) because when you synch on an object you are, in effect, telling the planetarium software about your polar misalignment. When you synch on an alignment star the planetarium knows where the star should be and it knows where you say it is, so it adjusts itself to compensate. But the tracking motor itself has no knowledge whatever of this polar alignment error. It just ticks away at a good approximation of the right rate. In order to compensate for polar misalignment both RA and Dec motors need to know what the error is because polar misalignment will affect both axes. We use autoguiders to give the motors the corrections they need to compensate for PA and other errors in the system.

Olly

[DaveGarland]

Hmmm I always try to get Polaris in the small setting circle. Surely I'm not using the wrong star? Its not as though Polaris is hard to find. Hopefully it'll be clear tonight and I can check.

[jambouk]

Do you rotate the RA to get the small polaris circle in the appropriate position according to the current time? Then use you altitude and azimuth bolts to get polaris in that small circle?

I suspect you are doing something amiss during your polar alignment routine.

Jd

[jambouk]

Oh and it is easy to use another star thinking it is polaris.

[lensman57]

Could anyone please tell me what is going on with my tracking. I have an EQ5 GOTO. Basically my confusion is this. If say I point my scope at Mars and centre it in the eyepiece, it gradually wanders off. After about 15 mins it will wander right out of view. Now this doesn't really confuse me as I know that it's only turning over its motor at what it thinks is the right speed. What confuses me is that if I tell the control to look at Mars, it moves the scope so that it is once again looking directly at Mars! How so? If it knows Mars is in that position at that time, why isn't it tracking it?

Thought please folks?

Check your PA and the balance of the scope. EQ5 is at its limit with a 200p and all the bits and pieces attached to it.

Regards,

A.G

[DaveGarland]

Quick update. I set up tonight and completely started afresh with the polar alignment. It looks like I have to suffer the embarrassment of admitting I may have polar aligned on the wrong star [emoji15] I litteraly have no idea how I managed this but I am pleased to report that my scope has happily been looking at the same star now for half an hour and is still DEAD centre in the eyepiece.

The lesson learned here is to never assume you are not a plank!

Thank you all for your input. We can file this issue as "Solved"

[hobsey]

Well done on getting it sorted.

To make you feel better, I too think I have been aligning on the wrong star as I have exactly the same problem with the planet moving from the center on the eyepiece which was making it very difficult to get a long run when imaging the other night.

[Merlin66]

Just a comment...

Multiple syncs in EQmod with improve the GOTO performance, but has no effect on the tracking rate or tracking accuracy.

[jambouk]

Glad it is sorted.

If i am in an unknown place when setting up, i ise a compass i carry around with my scope, to make sure the mount is pointing north. I seldom travel particularly far in terms of latitude so that is always generally in the right ball park - these two things means polaris is usually the only bright star in the FoV. What i also do is to stand back and swing my arm up the axis of RA and make sure it is in line with Polaris.

Really pleased it is sorted.

Jd