Az gti mount levelling

[AstroNebulee]

Hi, 

I wonder if other users of the az gti have noticed discrepancies in the bubble level on the star adventurer tripod (the one issued with az gti and tripod combos).  I love my az gti and the gitos are pretty stable but when it comes to levelling the set up I try to get the mount bubble level within the circle but then the tripod level is off. I'm wondering with is the best bubble level to follow as when the mount rotates the bubble level on the mount can change quite drastically. My workflow of setting up the mount consists of setting the tripod with mount snd extension pillar already on then trying my best to get the mount bubble within the circle, then point the scope to true north and use a spirit level on the scope between the tube rings as I always do a level North alignment. So is it best to just get the bubble level on the tripod as this wont move once set and then use my spirit level as normal on my scope. I really do think the level on the mount is off and I've tried it without the extension pillar and still the same.  I did see a thread on CN that touched on this slightly as said to just level the tripod and use a spirit level on the underside of the mount to check, which I will try but wanted to gauge az gti owners views on here. 

Edited May 13, 2021 by AstroNebulee
Addition

[StevieDvd]

If you are using it in eq mode then forget bubbles, the PA process will take care of the mount alignment.  It's nice to be level to make the adjustments a little easier/logical but by no means essential. And probably in Alt/Az mode the mount alignment process makes a note of the levelling and allows for it.

 

 

[AstroNebulee]

Hi Stevie 

Thank you, currently I'm using it in az mode but will in the future try eq when my star adventurer arrives using the wedge and counterweight bar. It's always been on my mind to ask why the two bubbles never match, I will try next time just levelling the tripod and then spirit level on the scope, it's probably just my ocd and wanting things level and straight 

[michael8554]

A level mount is important for Alt/Az.

"Calibrate" your separate spirit level.

Put it on any roughly vertical surface, and then on a roughly horizontal surface, note bubble position, reverse the level, if not the same position then in future "split the difference"

Measure in several planes on the mount, not the scope or tripod:

On the vertical white surfaces.

On the horizontal black top surface.

Adjust with tripod.

Then shouldn't change if you rotate the mount 90 degrees in Az.

Michael

 

[AstroNebulee]

Thank you Michael, I shall do this next time and have had a practice indoors so far. I bought a small 100mm spear & jackson spirit level so will do the job handsomely and not take ip any room in my rucksack. 

[badhex]

On 13/05/2021 at 20:25, AstroNebulee said:

I wonder if other users of the az gti have noticed discrepancies in the bubble level on the star adventurer tripod (the one issued with az gti and tripod combos).  I love my az gti and the gitos are pretty stable but when it comes to levelling the set up I try to get the mount bubble level within the circle but then the tripod level is off. I'm wondering with is the best bubble level to follow as when the mount rotates the bubble level on the mount can change quite drastically.

Glad you raised this - I have exactly the same issue! I also noticed that the bubble level on the mount has a sort of 'point' dead centre which the bubble seems to move around, but never directly on, if that makes sense? 

I only ever use the mount in AZ mode, and should mention that I'm a visual only observer. I tried initially with the tripod being level, then with the mount being level, but to get the mount level, the tripod itself was not just "bubble level off" but in so far off visually that it couldn't be right. 

In the end, for normal usage, after the level-north alignment and very minor adjustments to the first one or two targets, the goto itself seems to be close enough that I've assumed the mount bubble level is just not accurate. 

[AstroNebulee]

8 minutes ago, badhex said:

Glad you raised this - I have exactly the same issue! I also noticed that the bubble level on the mount has a sort of 'point' dead centre which the bubble seems to move around, but never directly on, if that makes sense? 

Im not glad someone else has the same experience as mine, if you know what I mean that these bubble levels are wrong. I had a practise of leveling the mount just by placing a spirit level on the underside of the mount on both axis as best possible,got it level then looked at the mount bubble and was way off so I think it's best not to read to much into these bubble levels. I use mine mostly for imaging in az at the moment until I fit a wedge and polar scope but this has caused many an issue whilst imaging. 

[badhex]

I took these photos last year with a view to posting but never got round to it. The first photo is the tripod (it's actually perfectly level, but couldn't get the camera angle quite right) and the second is the mount - both photos taken at the same time. 

[ScouseSpaceCadet]

I worried about the same issue, but then decided just to go by the tripod level with the mount attached.  It just made sense and seems to work fine.

The AZ-GTI's own bubble has a mind of its own. The bubble moves when the mount moves!

[badhex]

1 hour ago, ScouseSpaceCadet said:

I worried about the same issue, but then decided just to go by the tripod level with the mount attached.  It just made sense and seems to work fine.

Exactly this! 

[AstroNebulee]

Yes the mount and tripod level are completely out and the mount seems to be the faulty one a common sw fault with these, I guess it's all sorted by levelling the tripod or a small spirit level on the mount,