Stupid question

[gregbwfc]

Ok, here I go with the daft questions.

So I've got myself a Star Adventurer gti and have yet to use it in anger (this weather 🤦‍♂️).

I've never used a computerised mount before and want to check something before I potentially bust it.

I have a manual GEM.

To move the telescope around by hand, you unlock the axis clamps, find target and then lock them and use the slow motion controls for finer adjustments. 

Do I have the axes clamped before dialling in an object ?

Sorry if this seems a really dumb question, I've watched a few videos but can't see any mention of this.

[malc-c]

No question is stupid.  Yes in order to make any movement via the fine slow motion controls, or to have software control the mount the axis have to be locked by the clamps.  In fact, where a scope uses any goto feature the clamps should remain locked once the alignment has been completed.  If the clutches / locks are released and the scope is free to rotate even the slightest amount, any further gotos will be off.   

Of course if the scope is not motorised, then targets are found by releasing the clutches / locks, manually slewing the scope until the target is centralised in the finder, then the clutches / locks are locked and final adjustments made using the hand controls

[gregbwfc]

Thanks @malc-c, that's kind of what I thought.

Just had visions of me pressing go and the whole thing grinding as it tried to move 😳.

[Beardy30]

Yes lock by the clamps - and there’s no daft questions 👍🏼

[gregbwfc]

Ok, so we finally got clear skies so I was able to set up and have a go.

It worked just like you said 😀.

Didn't get objects centred but things seemed to be pointing in the right direction. 

Much better tonight.

Took a bit more time and care over alignment and it worked !

Which leads me to stupid question number 2.

So to test it out, I just chose objects I can see, M45, M42, Aldebaraan, etc. 

Now when I pick to go from Pleiades to Jupiter, I can see the direct route, but the mount moved the scope all around the houses.

It got there eventually but seems a long way round to do this.

Is this normal, or should I be altering some setting in the controls ?

Loved seeing Jupiter with its 4 moons strung out either side of it.

Forgot how good this hobby can be.

[Mal22]

Depending on where the objects you’re observing are in relation to the meridian line, a mount may go round the houses rather than “as the crow flies” to avoid the scope crashing into the mount during tracking. Clever mounts will also flip automatically during a tracking session when the object gets close to the meridian line, if “Meridian flip” is enabled in settings. 
 

And collisions do happen! I smashed the thermometer on my WO Z73 focus knob because I’d accidentally disabled meridian flip and it grinded into the mount for goodness knows how long… it could have been a lot worse! 
 

However, I will defer to brighter minds than mine on this particular instance, as given the time of your post yesterday and the objects in question, I don’t think the meridian line will have been a factor…

[gregbwfc]

Thanks for the reply 👍. 

I've heard of this meridian flip so I'll have a look into it.

Was just a bit odd that the mount did almost a full circle.

Still found the target ok 😀

[mikeDnight]

42 minutes ago, gregbwfc said:

Thanks for the reply 👍. 

I've heard of this meridian flip so I'll have a look into it.

Was just a bit odd that the mount did almost a full circle.

Still found the target ok 😀

This may help in visualising a meridian flip. This shows a refractor on a German equatorial, but the same principle would apply to any other design of scope on a German mount. Telescopes using an English fork design can travel straight past the meridian without the need to flip the scope.

Edited January 10 by mikeDnight

[malc-c]

13 hours ago, gregbwfc said:

 

Now when I pick to go from Pleiades to Jupiter, I can see the direct route, but the mount moved the scope all around the houses.

It got there eventually but seems a long way round to do this.

Is this normal, or should I be altering some setting in the controls ?

 

As others have mentioned, yes this is perfectly normal.  The weights should always be pointing downwards, and as Mike has show, such a move passed the meridian left the weights pointing upwards.  So in these circumstances the mount "flips" from one side to the other. 

[gregbwfc]

@mikeDnight. Brilliant, that explains it perfectly, thank you.

[peanutcol]

Pretty new to astronomy and owning a scope. Going through older posts and your name popped out at me so thought I'd say hi. Up the whites. I'm nearby in Hindley.

[Louis D]

On 03/01/2024 at 07:26, malc-c said:

In fact, where a scope uses any goto feature the clamps should remain locked once the alignment has been completed.  If the clutches / locks are released and the scope is free to rotate even the slightest amount, any further gotos will be off.

I thought the Sky Watcher Freedom Find mounts use encoders to keep track of alignment regardless of the clutches.

[Louis D]

On 10/01/2024 at 04:33, mikeDnight said:

Telescopes using an English fork design can travel straight past the meridian without the need to flip the scope.

Same goes for harmonic mounts without counterweights.  Not only that, they can track backwards just as accurately as forwards without backlash:

Watch for when totality begins and it starts scanning around the solar/lunar limb.  A direct drive could probably do the same thing as well.

Edited March 27 by Louis D

[malc-c]

21 minutes ago, Louis D said:

I thought the Sky Watcher Freedom Find mounts use encoders to keep track of alignment regardless of the clutches.

Some mounts are fitted with encoders, which mean drive clutches can be released and the scope manually moved without the handset loosing positioning.  However these will need calibrating from a known starting point first time used 

[Zermelo]

1 hour ago, Louis D said:

I thought the Sky Watcher Freedom Find mounts use encoders to keep track of alignment regardless of the clutches.

 

1 hour ago, malc-c said:

Some mounts are fitted with encoders, which mean drive clutches can be released and the scope manually moved without the handset loosing positioning.  However these will need calibrating from a known starting point first time used 

Yes, the SW Freedom Find feature uses dual encoders, and you can move the mount manually (provided you remember to switch on the dual encoder feature in Synscan each time you set up - the default is "off"). However, once you do that, the gotos for the remainder of the session are generally less accurate, because the second set of encoders are located on the coarse side of the gearing. I've found that it is still accurate enough to locate objects within an optical finder, unless it's having a hissy fit.

But I believe that the Star Adventurer doesn't have FreedomFind in any case.

[malc-c]

8 hours ago, Zermelo said:

 

But I believe that the Star Adventurer doesn't have FreedomFind in any case.

Nothing is mentioned in the features on FLO's website.. But I did find a reverence to servo motors and encoders on one website, but it just mentioned GTi mount ?