AZ GTi Nothing But Issues - Accuracy Apalling

[dd999]

15 minutes ago, laudropb said:

Using the auxiliary coder is supposed to decrease the accuracy of the go to. It enables freedom find, but I think it’s worth a try. Also making your last movement when centring an object  a move to the right and up does make a slight difference in accuracy.

I will give this a try and set this on. Tonight will be my final night of trying before sending it back - it's worth a try as the mount really looks as if it has potential. Usually the app forces the move up and to the right before confirming position anyway, so hope this part is already covered, but will check.

[Stu1smartcookie]

16 minutes ago, dd999 said:

I will give this a try and set this on. Tonight will be my final night of trying before sending it back - it's worth a try as the mount really looks as if it has potential. Usually the app forces the move up and to the right before confirming position anyway, so hope this part is already covered, but will check.

Hope you get this mount working 

[ScouseSpaceCadet]

1 hour ago, laudropb said:

Using the auxiliary coder is supposed to decrease the accuracy of the go to. It enables freedom find, but I think it’s worth a try. Also making your last movement when centring an object  a move to the right and up does make a slight difference in accuracy.

I've read the same, the auxiliary coder decreases accuracy. However, I've also read it increases accuracy! My auxiliary coder is on, and accuracy is ok up to now. Freedom Find is crap though!

 

[rob_r]

1 hour ago, dd999 said:

Usually the app forces the move up and to the right before confirming position anyway, so hope this part is already covered, but will check.

Most do, I think I read somewhere it is so the gear teeth engage and reduce alignment errors due to mechanical backlash. Very strange with the alignment issues though, usually mine is good at getting targets within the FOV (not necessarily centred) with a 25mm EP. Perhaps try a 3 star alignment if you haven't already, there are a few more threads regarding alignment issues with this mount. Hope you get it sorted one way or another.

[dd999]

Thanks everyone - clear skies again tonight, so fingers crossed!

[dd999]

...

Edited July 30, 2020 by dd999

[dd999]

A much different night last night!

I made some bigger changes to the approach, but after this the goto was very accurate all night long - centering everything almost perfectly, as I went to from one object to another.

Here are the changes I made. Unfortunately they weren't in isolation, so I'm not sure the true root cause, but perhaps they all played their part:

• Changed from using the Synscan app to using the Synscan Pro instead (not for any other reason other than trying something different);
• I leveled off the tripod with a spirit level reader at the start of the night - although I think it was 98-99% accurate before;
• I changed scope - I went from my 4kg SW 130p to the lighter 3kg SW 102 ST;
• Replaced the batteries in the AZ GTi! 

Embarrassingly it may have been the batteries (and I may have to switch to a power pack) but the 1kg saving in weight on the scope may have helped too. I kept the auxilliary encoder off (not that I tried it with it on to see if it made a difference) but it was very accurate enough without.

Thank you all for your helpful suggestions - and a much less stressful night!

Edited July 31, 2020 by dd999

[Stu1smartcookie]

17 minutes ago, dd999 said:

A much different night last night!

I made some bigger changes to the approach, but after this the goto was very accurate all night long - centering everything almost perfectly, as I went to from one object to another.

Here are the changes I made. Unfortunately they weren't in isolation, so I'm not sure the true root cause, but perhaps they all played their part:

• Changed from using the Synscan app to using the Synscan Pro instead (not for any other reason other than trying something different);
• I leveled off the tripod with a spirit level reader at the start of the night - although I think it was 98-99% accurate before;
• I changed scope - I went from my 4kg SW 130p to the lighter 3kg SW 102 ST;
• Replaced the batteries in the AZ GTi! 

Embarrassingly it may have been the batteries (and I may have to switch to a power pack) but the 1kg saving in weight on the scope may have helped too. I kept the auxilliary encoder off (not that I tried it with it on to see if it made a difference) but it was very accurate enough without.

Thank you all for your helpful suggestions - and a much less stressful night!

Glad you had a better evening ... Batteries have their place but are unreliable . I honestly wondered about the weight on the 130. But this mount can allegedly take 5kgs so i thought it would have been ok . But a lesser payload will pay dividens

 

Well done for persevering . 

[dd999]

I must admit after attaching a 130p scope I also added a dslr so this really pushed the 5kg payload. I increased things even further and tried to add my mobile phone to a ball joint attached to the dslr - the AZ GTi didn't like this and couldn't move! Lesson learned there.

I'm going to get a SW 72ED - but I'm thinking about selling my 130p and getting a 130pds, one reason for visual (and I find the reflectors so much more comfy for visual than a refractor - and the 130p is one of the smallest) and also so I can attach a dslr and image planets and lunar if I want. 

I may though have to test out the performance of the mount when loaded with the 130p and dslr - with the new batteries (or power pack) and see..........I just don't want to wear the little fella out!  

 

[ScouseSpaceCadet]

Yay! 👍 Lol. Now try the 130p on it tonight. 😀

 

If you need power supply ideas, I use this:

Ipossible Power Bank  in a pouch strapped to a tripod leg, with a 5v - 12v step up converter plugged into the 2.1a USB socket.

Quite handy because at the same time you can keep the phone charged via the 1a socket.

Edited July 31, 2020 by ScouseSpaceCadet

[Stu1smartcookie]

i have a sw 72ed (brilliant little scope ) 1.9kgs , plus the extras such as FF and Camera , so in essence around the 3kg mark .. it will be ideal for that mount ... even thinking that maybe i need yet another one  

[dd999]

It appears my celebrations were a little too premature! 

Tonight I tested the same setup but this time with the SW 130p. The accuracy was better, and each time landing the object in my 25mm eyepiece BUT the biggest problem I seem to have is the mount isnt 'learning' 

For example I goto Jupiter - it placed Jupiter just to the very edge of my 25mm eyepiece. I center and then confirm to the app once centered. It just doesn't remember this for next time. 

Its so bad that I go to Jupiter (where again it puts Jupiter at the edge of the view), I center and confirm. Then I immediately ask the app to goto Jupiter again..... and immediately it puts Jupiter to the edge of the eyepiece again. I would have expected the app to confirm it's already centered and not try and reposition the mount. 

I tried 6 or 7 times in a row to center Jupiter in the eyepiece, confirm to the app when I have centered - and then immediately goto Jupiter again. Each time the same result, it took Jupiter from the center of the eyepiece to the edge again. 

It was the same again back and forth between Jupiter and Saturn too. 

Last night was a little different with the SW 102 ST as I wasn't observing through an eyepiece as my dslr was connected. I just took photos after each goto and the object looked 'pretty much' centre. So I didn't have to mess around centering and recentering. 

I also tried switching the auxillary encoder off and on during the tests but it made no difference. 

Surely if I center an object, the mount should be remembering this for next time? - or does the mount not act this way? 

 

Edited July 31, 2020 by dd999

[robhatherton]

The auxiliary encoder is only needed if you are going to, for instance after using a goto, manually push it to your next target and the mount will remember it’s alignment. You don’t need it and it actually reduces accuracy if you only use the motors. But whatever alignment you use the mount “expects” to start off level and pointing north. Any of the two star alignments work well for me and then it’s accurate enough to place the target near the centre of a low power eyepiece.

[dd999]

In this example with the 130p I did start north (and used a compass for precision) as well as making sure my scope was level before it carried out the North two star alignment process on to the first star - Dubhe - before heading off to Altair. 

It just seems to be the mount not making corrections when I'm having to manually center which ever object I go to. 

What I'm not sure of though is whether the mount is supposed to be 'correcting' and learning each time I go to an object and then have to manually centre and confirm....... or whether at that stage the mount already has its plot of the sky, and the centering is for viewing comfort only?? 

 

[dd999]

On 31/07/2020 at 12:57, ScouseSpaceCadet said:

If you need power supply ideas, I use this:

Ipossible Power Bank  in a pouch strapped to a tripod leg, with a 5v - 12v step up converter plugged into the 2.1a USB socket.

Quite handy because at the same time you can keep the phone charged via the 1a socket.

Cracking suggestion by the way! - I was going to look at the larger powerbanks, but this is a much better solution! 👍

 

[ScouseSpaceCadet]

10 hours ago, dd999 said:

Cracking suggestion by the way! - I was going to look at the larger powerbanks, but this is a much better solution! 👍

 

Thanks. The AZ-GTI requires 750mah, the converter outputs up to 800mah so it works fine, being a cheap, light weight & portable solution.

Ideally, to reduce the risk of dew intrusion, mount the power bank side on or use a holder/pocket/pouch that covers the top.

[robhatherton]

I managed to get 8 rechargeable aa batteries and a charger that will take them all for about £20 from amazon. 

[Starwatcher2001]

On 31/07/2020 at 23:30, dd999 said:

It appears my celebrations were a little too premature! 

Tonight I tested the same setup but this time with the SW 130p. The accuracy was better, and each time landing the object in my 25mm eyepiece BUT the biggest problem I seem to have is the mount isnt 'learning' 

For example I goto Jupiter - it placed Jupiter just to the very edge of my 25mm eyepiece. I center and then confirm to the app once centered. It just doesn't remember this for next time. 

Its so bad that I go to Jupiter (where again it puts Jupiter at the edge of the view), I center and confirm. Then I immediately ask the app to goto Jupiter again..... and immediately it puts Jupiter to the edge of the eyepiece again. I would have expected the app to confirm it's already centered and not try and reposition the mount. 

I tried 6 or 7 times in a row to center Jupiter in the eyepiece, confirm to the app when I have centered - and then immediately goto Jupiter again. Each time the same result, it took Jupiter from the center of the eyepiece to the edge again.

Beware I might not know what I'm talking about, but could this be backlash?  My thinking is that if the scope's last goto step is up and right, and you're correcting this to centre it in the eyepiece using down and left, maybe the slack in the gears might be the difference. Subsequent attempts are just repeating the problem. Mind you 1/2 the FOV in a 25mm ep is  a long way.

[banjaxed]

44 minutes ago, robhatherton said:

I managed to get 8 rechargeable aa batteries and a charger that will take them all for about £20 from amazon. 

You might be adding to your problem by using rechargeable batteries as they are only 1.2volts instead of 1.5 volts. If I remember rightly the voltage is critical on that mount.

[dd999]

1 hour ago, Starwatcher2001 said:

Beware I might not know what I'm talking about, but could this be backlash?  My thinking is that if the scope's last goto step is up and right, and you're correcting this to centre it in the eyepiece using down and left, maybe the slack in the gears might be the difference. Subsequent attempts are just repeating the problem. Mind you 1/2 the FOV in a 25mm ep is  a long way.

Mmm possibly, but as you say the 25mm eyepiece is giving a reasonable size FOV, so I would hope that one up and right wouldn't be causing the problem, but who knows!

I'm just not sure if the mount should be remembering my re-centering, and calibrating as a result - or if it doesn't do this and my manual adjustment to center and confirm is for my own visual comfort.

My guess is that it should be re-callibrating based on my re-centering otherwise what's the point of the mount asking you to manually center and confirm once done (?)

[Colinhunter]

I always had trouble with this Mount when using batteries. Sometimes pointing down, parking then moving again. I noticed that the battery connector is a little iffy and sometimes lost connection as the mount skewed. Since getting a power lead it’s been More or less trouble free.  I was overloading it in the end so got a heq5 pro for my scope and use the Gti for my dslr 

[dd999]

If anyone else happens to stumble across this thread, searching Google for a similar issue (as I regularly do!) I want to update this post to say everything seems to now be working fine.

I tested again and this time attached my 'heavier' 130p telescope with a dslr attached, just to see if the mount could handle the weight, and whether I could improve the goto accuracy. This time it worked fine and the mount remembered my manual adjustments for next time.

The only thing I have noticed is that after each session the AZ GTi mount attached to the extender tube comes a little loose. So if you leave your AZ GTi mount attached to the extender tube you may need to unscrew and re-tighten after each session. Being loose would certainly cause a decrease in goto accuracy.

My lessons learned were to re-tighten the mount to the extender tube after each session, and making sure batteries are topped up (or as ScouseSpaceCadet says, get a powerbank!) - also if the goto starts behaving improper, just try realigning again (only takes 2-3mins to North Star align) ....before you decide to drop kick it! Trust me I've been tempted!

Thanks to everyone for your help, as always.

 

Edited August 7, 2020 by dd999

[robhatherton]

On 04/08/2020 at 13:53, banjaxed said:

You might be adding to your problem by using rechargeable batteries as they are only 1.2volts instead of 1.5 volts. If I remember rightly the voltage is critical on that mount.

I felt I should add, in case anyone else wants to try this, I’ve had absolutely no problem using rechargeable batteries!

[procky1845]

Hi,

I had some issues initially with my AZ-GTi, some issues were resolved my finding the correct sequence of steps, the other and probably biggest improvement was when I upgraded the tripod. I bought the Skymax 127 with the mount and tripod as a bundle and I don't think the tripod was up to the weight. As soon soon as I upgraded the tripod to something more substantial I noticed an immediate increase in accuracy. For example, it was then possible to do a daytime alignment using the sun and easily find Venus/Mercury, something that was impossible previously.

 

Typical steps I go through now if I want to use go-to are:

1) Setup tripod, level and ensure pointing north (I point one tripod leg north for reference).

2) Attach mount, scope and all attachments e.g. diagonal, RDF, and also stick an eyepiece in for the weight.

3) Point the telescope north using the north facing tripod leg to gauge

4) Loosen the alt clutch and ensure the scope with all peripherals is well balanced, if not loosen the saddle and rebalance the scope, then level the scope and tighten alt clutch again.

5) Turn on the mount, connect and reset alignment in the synscan app

6) Do a north level alignment

 

A few things that caught me out previously:

- The aforementioned tripod issue (wasn't sturdy enough and once I realised, you could actually see the tripod slightly leaning to the side with the scope attached)

- As has been already mentioned somewhere in this thread, the head of the extension pillar needs to be properly tightened to the base of the mount, especially if you are going to adjust the azimuth manually by slackening the az knob.

- For a period I attached my old straight through finder from my 200p dob that wasn't being used anymore instead of the red dot finder, this tipped the weight over the edge for the mount with the Skymax 127, and meant that when the mount was making altitude adjustments or tracking a certain amount of error would seep in.

 

Now that I've been through the pain of understanding it however, it really is a great mount. There was some early frustration though.

 

Lee

[George Gearless]

At the risk of being Captain Obvious here, I do suggest checking that the clutches are tightened properly.

Your description sounds very much like the same problems I went through, until the headslapping moment where I realized what was wrong.

In addition, do check the nuts and bolts that connect the mount head and the tripod. When my accuracy once again started to deteriorate, but the clutches were finger tight as they should be, I found that the nuts slowly but surely were coming lose. This mount does require regular checkups. But if you do, I really can't think of anything bad to say about it.

Hoping you get it sorted.

George