New Mounts woes

[Bobby1970]

Recently i purchased an Opticstar EQ1300 GT. It seemed like a good alternative to a Skywatcher EQ5 synscan goto. Higher payload capacity and ball bearing races on both axis, plus a price of £495 so i went for it.

I have only had two chances to use it so far and am regretting buying it right now. 

I align the mount using sharp cap polar alignment feature, altair gpcam with a 70mm travelscope on top of the ST120 on the mount. I have aligned within 30 seconds of the pole both times i have used the mount.

I then choose a three star alignment, the only stars available to me are deneb, altair and vega. So i use them. Following alignment everything over in that area of the sky seems pretty good, objects appear pretty central in my 24-8mm eyepiece at 8mm even. However when i tell the mount to goto M31, in the opposite area of sky it is no where near being in view. Neither is anything else in the opposite side of the sky. :-(

 

I have double checked my lat and long co ordinates and the date to make sure they entered correctly, and they are.

The mount also seems to be emitting a sort of electrical "crackling" sound from the RA drive area i think. Opticstar tell me this is "normal" when the RA drive is tracking, however, the noise is present before i have even attempted the 3 star alignment  (i.e. the mount isn't tracking) so i fail to see how it can be.

I have tried powering off, and restarting the whole procedure, but there are only ever the same threes stars to choose from regarding alignment. In fact, as the night wore on and after several re-starts there was eventually only one star listed, Altair, for the 3 star alignment???????. 

I have already had some email correspondence with OpticStar, but so far what they have suggested still does not appear to work.

Currently wishing i hadn't bothered even getting anything and just stuck with the Star Adventurer and camera/lens or ST80. 

 

 

 

 

 

 

[nightfisher]

how long have you had it, not long i would guess, so ask them to take it back for a refund..........simples, i dont know this mount so cant comment on the workings of it

[Cornelius Varley]

Have you tried 1 or 2 star alignment ?

The noise you hear from the ra motor is normal, the mount will start to track in ra when switched on, even if it not star aligned.

[Chris]

Hi, my first thought is you're aligning to 3 stars in the same region of the sky, all three are pretty close to each other. I'm in a similar boat i.e can't get widely spaced stars for alignment so also can't accurately hit objects right over head, I couldn't find M31 with my HEQ5 pro the other night but did accurately find M15 and Uranus. I'm almost 100% it's your choice of stars with that issue, can't you see any other bright-ish stars you could try?

 

[Davey-T]

Is it doing a meridian flip when going to M31 ? I've had "expensive" mounts that are incapable of finding anything once flipped.

Are you sure you can't select your own alignment stars in the handset ?

Dave

[ronin]

Quote

I then choose a three star alignment, the only stars available to me are deneb, altair and vega. So i use them. Following alignment everything over in that area of the sky seems pretty good, objects appear pretty central in my 24-8mm eyepiece at 8mm even. However when i tell the mount to goto M31, in the opposite area of sky it is no where near being in view. Neither is anything else in the opposite side of the sky. :-( 

Not a great deal of help but I have seen this reported either previously or elsewhere, about 3-4 months back. I cannot recall the workaround, or how they fixed it.

You description of polar alignment reads that you are using the scope to align with? You do not mention a polar scope but do mention the 70mm and the ST120. Just wondering if the mount is not actually polar aligned. In case you are using either scope for polar alignment I suggest you do not. That aspect should be done via the polar scope of the mount. Unfortunately the manuals can use the same term "alignment" for both operations, polar and goto alignment, but they use different processes and equipment.

 

[Bobby1970]

Thanks for the replies chaps/chapeesses. :-)

 

I will try and answer the points raised.

Firstly for polar alignment i point the mount north and make sure Polaris is in the middle of the polar scope initially, then i follow the procedure using SharpCap polar alignment by using my altair GP Cam and a 70mm travelscope piggybacked on the ST120, details here:-

 https://stargazerslounge.com/topic/269291-sharpcap-29-polar-alignment/?page=3#comment-3074008

 

Once polar aligned i then use the 3 star alignment feature within the handset, after entering the date and my observing site details obviously, which i have checked over and over again.

The only stars which are available to select are Altair, Deneb and Vega. I have never seen any other stars shown for selection. In fact, last night, later on i powered down the mount and decided to start over again, however there were only two stars listed, (altair and deneb) this time, even though i had selected a 3 star alignment????

There is a feature called "target sync" which says that you can select a star in a different area of sky to improve the goto, but i would have thought that i should be able to select stars from different parts of the sky for my initial alignment anyway??

I have no idea what a "meridian flip" is. lol, so do not know if i have done one, or need to do one. lol

So far OpticStar have been pretty good, they have asked for details relating to my observing site, location, time etc. And are going to see how a mount at their end performs and are concerned regarding the noise i have described. Peter at Opticstar has assured me that he will get to the bottom of it, so fingers crossed.

 

 

[Chris]

\What?? The hand set only gives you a choice of 3 stars right near each other for a three star alignment? That's a bit bonkers! I thought you meant you could only see those three bright stars from your observing site so selected them.

Ask Opticstar if it's normal to only have a choice of three stars all near each other for the three star alignment? Doesn't sound right to me! for a start the stars you selected form the summer triangle, what happens when the summer triangle appears low on the horizon later in the year for example?

[Freddie]

Odd, manual actually says the alignment stars should all be in the same meridian, 30 deg apart and form a triangle. Not heard that one before.

[steppenwolf]

Quote

The only stars which are available to select are Altair, Deneb and Vega. I have never seen any other stars shown for selection. In fact, last night, later on i powered down the mount and decided to start over again, however there were only two stars listed, (altair and deneb) this time, even though i had selected a 3 star alignment????

For me, this is the cruncher - Altair, Deneb and Vega are far too close to one another for a three star alignment UNLESS you are only expecting to observe/image within this triangle. Does your mount only work in a 'Zone' arena? If so, this may explain why the suggested stars are so close to one another but I would want to be allowed to align in three totally different regions of the sky.

Quote

I have no idea what a "meridian flip" is. lol, so do not know if i have done one, or need to do one. lol

A meridian flip is required by all equatorial mounts once the object you are observing or imaging passes its culmination point (i.e. passes through its highest point in the sky) - the 'flip' moves the telescope from one side of the mount to the other to re-point at the same object to ensure that the eyepiece/camera doesn't crash into the tripod or pier.

[Freddie]

I assume when it brings up the first alignment star, you are using the arrow key to scroll down to see if others are available? Same with 2nd and 3rd star.

[Chris]

Freddie might have a point, I just can't believe you would only have 3 stars to play with.

[steppenwolf]

Quote

I just can't believe you would only have 3 stars to play with.

+1

[Bobby1970]

i checked again today, powered the mount up, set the date and time as last night. Went to t3 star alignment, altair,deneb, vega. Thats all can cycle through them with direction keys on handset. Once you select the first one you can cycle between the remaining ones.

As time went on last night, the 3 star alignment actually only showed 2 stars then only one star, following restarting the alignment process. 

I would have thought there would have been a list of stars all over the sky, similar to a skywatcher mount. 

 

[Freddie]

So once you have selected 3 star align you have a choice of 3. You select one and the scope slews to it. You adjust the position of the scope with the keys until the star is central and press confirm. You then only have a choice of the two remaining stars you didn't choose from the original list. Is that correct?

[Thalestris24]

Hi

Looking at the ad for the mount, it seems it has a number of catalogues so maybe you have to select a different one to do the star alignment?

Louise

[ollypenrice]

4 hours ago, steppenwolf said:

 

A meridian flip is required by all equatorial mounts once the object you are observing or imaging passes its culmination point (i.e. passes through its highest point in the sky) - the 'flip' moves the telescope from one side of the mount to the other to re-point at the same object to ensure that the eyepiece/camera doesn't crash into the tripod or pier.

Just add 'German' in front of 'all equatorial mounts' for the pedants! But, yes, I agree on all counts.

When people say that they have a PA within 'x' arcseconds I presume they are taking this from a software/hardware package which is giving them this value. I am invariably suspicious, having found no end of issues coming from polar misalignments which are far worse than the software/hardware packages claim. There are some easy tests to demonstrate this. Just over a week ago I was trying to help a guest with data taken in the UK. To test the PA I took his first and last sub from a roughly 5 hour run and stacked them in Astro Art using an alignment routine which works in x and y but not in rotation. The field rotation was obvious. There are some good PA products out there but if you want to do a PA routine which eliminates software and hardware errors just do a drift alignment. For all that, I get the feeling that this mount software has a problem.

Olly

[Bobby1970]

3 hours ago, Freddie said:

So once you have selected 3 star align you have a choice of 3. You select one and the scope slews to it. You adjust the position of the scope with the keys until the star is central and press confirm. You then only have a choice of the two remaining stars you didn't choose from the original list. Is that correct?

thats exactly how it is, at least so far.

[Bobby1970]

2 hours ago, Thalestris24 said:

Hi

Looking at the ad for the mount, it seems it has a number of catalogues so maybe you have to select a different one to do the star alignment?

Louise

there doesn't appear to be an option for this. You are simply presented with 1,2 or 3 star alignment options. when selecting the 3 star alignment option i am presented with the three stars mentioned earlier

[Thalestris24]

16 minutes ago, Bobby1970 said:

there doesn't appear to be an option for this. You are simply presented with 1,2 or 3 star alignment options. when selecting the 3 star alignment option i am presented with the three stars mentioned earlier

But you can select a particular catalogue otherwise? Perhaps Opticstar will come back with some advice.

Louise

[Tim]

I wonder what alignment star options you would get if you set the date as March 15th or so?

For a decent general alignment, three stars widely spaced should give you a half decent pointing model. However, if you want to be particularly accurate, then it is suggested that three stars within a close-ish triangle (like the three you have) are chosen, and then targets in their immediate vicinity should be found with greater accuracy.

To be honest, I would be thinking about swapping for the HEQ5, if that might be an option, the mount and software is pretty much bombproof. I regret selling both of mine :/

 

[Uranium235]

Yep, it does seem bizarre that you have only three stars to choose from.... that cant be right. What kind of muppet would write firmware with such a limited set to choose from?

Probably best to give them a call to see if this is normal... if it is, send it back and get a refund.

[Paul M]

My thoughts for what they are worth:

You seem to be getting usable alignment using the Summer triangle stars. I've done the same and had no issues. If you are then getting usable Goto in that area of the sky I'm sure it won't be so far off over at M31 as to fail to find it.  It's a huge object to start with. Are you sure it isn't there? With a poor sky and light pollution it might be washed out.  

If it isn't there how far away is it? 

The alignment star issue is odd. And the list seems to get smaller as objects set or get lower which is normal.  But new objects should be rising. 

I don't know the mount.  Is there any way you might have applied filtering to the list? Such as magnitude or altitude? I can't work out why capella isn't listed even if there is a magnitude filter . 

I guess the mount is a rebadged OEM affair. Perhaps there is more stuff about this mount under a different brand name. Might be worth researching. 

[Bobby1970]

popped out to the garage and powered up the mount, set the date to 15th March as suggested above. 

Stars now available for 3 star alignment are :- Procyon, Betelgeuse, Aldebaran, Regulus, Capella, Rigel.

 

????

[Freddie]

It appears to be doing what it is designed to do then. Just a very odd way of getting an alignment with stars all in the same meridian and so close.