Maybe you need better cable management. The way they hang off everything in your picture could be pulling things askew as you make your rotations.

Edit: apologies. I was looking at tkottary's image.

Oh, of course. Apologies. Spatial visualization is not my strong suit -- I depend on my wife for all the geometric thinking. And yes, I am aware that men average better at that than women. We're both outliers, it seems, just in opposite directions.

I am really interested in trying this -- it's just so appealing to bung the adapter into the end of the polar-scope hole and Bob's your uncle. OTOH I'd be running exactly the same procedure in software, so maybe I'm better off just leaving the 120 on the guidescope in the first place.

I am wondering whether this might be an iOptron driver problem. I have a similar issue with my iOptron SmartEQPro+. My Atlas Pro mount, by contrast, aligns just fine using the EQMOD driver.

There were reports that Ekos PA tool would advise you to go in the opposite direction. So try this, use Ekos PA again, but this time, go completely in the opposite direction, does this help at all?

If this somehow ends up working, we need to figure out what makes your situation different as I have no idea what leads to this.

Thanks Jasem. I'll try this but I have my suspicions now turned towards this.... See the attached screenshots, one is within the PA tool after it takes the 3rd rotation exposure (Polaris is exactly identified). The other one is a simple plate solved exposure taken at a different time. I don't remember if I had the mount in the same exactly position but the coordinates look close. In this one Polaris is NOT identified correctly, which is weird! Perhaps this doesn't affect the Alignment Tool but I'm not for certain!

You forgot to attach.

So noisy! Why such short exposures?

A few nights ago I got to test my ASI120MM 'polemaster' with a 50mm lens mounted in the center of my HEQ5 Pro. It worked flawlessly, easily achieving a 1 minute error within minutes on the first iteration. Undoubtedly I could have gotten sub 1 minute with a second adjustment, not that it would be much benefit to be that precise on a temporary setup with autoguiding.

I know that this has been a while, but do you happen to have the STL file for this adapter that you could share? I'm looking for something exactly like this. Thanks!

What do you require exactly?

The problem with the original design of the adapter is that it is held in by the rubber O-rings, not by a secure clamp. That probably makes it shift as the mount rotates. If a clamp solution can be incorporated into the design that prevents shifting as the mount turns, it will work fine.