Beginner tutorial - how to set up a meridian flip on a ZWO ASIair Mini

 How to Set Up Meridian Flip in the ASIAIR Mini

My experience of Meridian flips using the ASIair Mini and my EQM – 35- PRO mount has not been a good one thus far – twice I’ve failed to get a meridian flip to work. However, a few nights ago I saw what it should look like and gained some useful tuition from WA Emery, when we were both imaging down at Wembury.

So, in this post, I go through

·       What the meridian flip is

·       What you need to check before programming one into your ASIair

·       How to make the settings changes

·       What happens during the flip

 

Let’s get stuck straight in then:

A meridian flip is an automatic manoeuvre that slews the telescope to the opposite side of the mount when the target crosses the North-South meridian; preventing a collision between rig and mount and continuing your imaging session safely.

 

Before you start, make sure:

·       Your mount supports GoTo and ASCOM/EQMod protocol when used with ASIAIR

·       Your mount is correctly balanced on both sides

·       You’ve done a successful polar alignment

·       You’ve checked that plate solving is working and is correct

·       Your time, location, and mount parameters are correct in the ASIAIR app

To program the flip:

·       Connect Your Mount in ASIAIR as normal

·       power everything up and open the ASIair app

·       Connect the ASIAIR Mini to your mount (via USB cable or WiFi depending on mount).

·       Confirm mount is set to "Equatorial" mode.

 

This will all ensure that your ASIAIR knows the mount’s exact position and orientation to calculate when the meridian will be crossed.

 

To enable the Meridian Flip in the app:

 

·       ASIAIR App → Mount → Meridian Flip Settings (may be AMF – auto meridian flip)

·       Toggle AMF to on - This tells ASIAIR to monitor the mount’s RA position and automatically execute a flip when needed.

·       Enable Auto-Guiding Interaction – mount – flip settings menu – ‘stop guiding before flip’ - you need to enter the number of minutes you want to stop guiding before the flip – I normally do it 3 minutes before the flip time – which you can find at the bottom of the app screen. Your ASIair app and mount will work together now to identify when your imaging object will cross the N/S meridian – and it will stop the guiding (but not the tracking) X minutes before hitting the meridian line.

·       “Do AMF X minutes after Meridian” – this is how long you want your mount/guiding to wait after passing the meridian before slewing to target once more, plate solving and resuming guiding and shooting images.

Next:

·       “Recalibrate After Flip” is optional (usually not needed with high-quality mounts) but I do it because it prevents guiding from fighting the flip and ensures post-flip guiding resumes cleanly on the opposite pier side. Again, enter a time for when the mount/guiding will resume after the meridian flip.  

Points to note:

The bottom of your screen shows the time to elapse before a meridian flip is required.  I always watch my meridian flip to ensure no cables snag during the process. Remember, if your imaging exposure time risks crossing the meridian flip time, the ASIair will stop imaging before the flip so that you don’t get a partial image. This means it could be a lengthy wait before things resume the other side of the flip – e.g. 3 mins stop before flip +cancelling a 5mins exposure+ 5mins after flip+ restoring guiding and plate solving – you could lose 15 – 20 minutes of imaging time for the whole process to complete.

 

When you have entered your settings, all you need do is then start an imaging plan or autorun as you’d normally do.

Once started, the ASIAIR will display a Meridian countdown beneath the mount info (e.g., “Meridian in 32m”). The flip will only occur during an active imaging session.

 

What Happens During the Flip (Automatic)?

 

When the flip moment arrives, ASIAIR will:

·       Finish the current exposure

·       Stop guiding

·       Slew the mount to the opposite side

·       Plate-solve to re-centre your target

·       Restart guiding (with/without recalibration based on your settings)

·       Resume imaging

 

I hope this helps – this is the crib sheet for my next outing to ensure I haven’t forgotten to do anything. I will let you know how I get on.

In the meantime, as always, if I have forgotten any stages, got anything wrong or you just have some further tips to make a meridian flip experience better, do drop a comment below so we can all better learn.

Clear skies, stay safe and have enormous fun as always

Steve

PS I found this video useful

https://www.youtube.com/watch?v=nOZFmxMBbZM

Technique - Lost in Space and Meridian Flips

First visit to this astronomy/astrophotography blog? Well, firstly a warm welcome to you and thanks for stopping by. After reading this post, if you want to find out more about me and this blog, why not visit my introductory page at https://undersouthwestskies.blogspot.com/2025/01/welcome-to-my-new-astronomyastrophotogr.html You can also browse other posts by using the search bar or the blog post list on the right hand side and I'd really like to hear from you via the comment boxes. Drop me a tip, an observation or a question. Take care and clear skies to you. Steve

 Astrophotography is a funny old game isn't it. Take last night. Target IC 4604 - The Rho Ophiuchi complex. 

My best ever polar alignment and set up times. A clear sky, faint breeze and a 37% moon. The tide almost in and breaking over the rocky foreshore below the car park. The distant rhythmic flash of the Eddystone Lighthouse and far out in the English Channel, lit up ships passing in the night. 

ISO 800, 240" x 20 plus calibration frames. My little radio tuned to Radio Four and then The World Service. My primus stove hissing and bubbling away away when I felt the need for a warming cuppa. 

Astrophotography and astronomy have taught me much over the last few years about the night sky, how to use my cameras, mounts and telescopes/lenses; and of course imaging techniques. A newly found passion for astronomy, astrophotography and art! And all the time, I have been developing my scientific knowledge, use of technology and problem solving thinking. My son-in-law has even ignited within me an interest in 3D printing and the potential it has for creating little helpful bits and pieces for my various astronomy/astrophotography rigs. 

As a person, I have developed more. My patience is much better! My concentration and focus back to pre-retirement levels! And my blood pressure? So much lower! Out at night, under the stars, I am relaxed, pondering, reflecting, asking some big questions, just tuning in to a radio programme I wouldn't have likely heard had I not been up at that hour! 

My friends would say that I've become even more nerdier than I was and that isn't a bad thing at all. I can chatter away about the night sky forever! 

But then it isn't all rosey is it! 

I keep 'hitting a wall!'

One wall is using SIRIL and Generalised Hyperbolic Stretches. I have watched all the Youtube videos. I've taken notes. I have practised and practised - to no avail. I am still none the wiser! 

Another 'wall' is using the ASIair plate solving.  

How did I miss Rho Ophiuchi? I mean how? On my screen in plate solving it was clearly identified and central. When I did the sky atlas stuff - it synched correctly. 

But, as you can see, all the bright cloud colours - where are they? I missed my target! By quite some way! Unbelievable! I am laughing about it - serves me right and a lesson learned. Check that I have the right co-ordinates in RA and Dec! 

Plenty of 'cloud and dust' stuff

ISO 800  240" x 20 

20 of each calibration frame

Canon 800D, Zenithstar 61ii with field flattener 61A, EQM-35-Pro mount, ASIair mini, RVO 32mm guide scope with ZWO 120mm mini guide cam, Celestron Lithium Pro battery pack 

Processed in SIRIL, GraXpert and Affinity Photo. 

If you can identify where in space I ended up in this shot, I'd be grateful! 

Conclusion 'Lost in Space' somewhere! 😕😩😆

Meanwhile here is my third 'wall'. How do you perform a meridian flip on the EQM35PRO using an ASIair mini? 

I thought I had the right settings last night and it sort of performed a flip but the cables twisted and wrapped themselves around the mount and so when guiding restarted it was shambolic. I ended up doing a manual meridian flip; after I had unplugged various cables to ASIair mini and my DSLR. That of course meant rebooting everything and doing a new polar alignment. 🙄

It is hard work being a newbie and novice isn't it 😉😆

If your gear hasn't don a meridian flip yet and you are using guiding with an ASIair - here are two helpful videos that explain the process