Skywatcher Mak-Cass and Moonlite

[Jose Auger]

I just bought a new Skywatcher Maksutov-Cassegrain 180. I ordered a Moonlite focuser with the 2 inch regular thread profile. Now I discovered that when I removed the tube that holds the star diagonal the size of the threaded opening where the Moonlite should be screwed is smaller than the Moonlite opening. There remains a flange in the telescope tube but it is extremely tight and I am afraid to remove it as I do not know if there is a bigger threaded opening under it or if it is holding something. In the photo included I tried to show the flange.

Moonlite is willing to help in terms of changing the focuser, but I would like to know from people with the same scope that are using Moonlites, if the flange can be removed and the focuser installed in whatever threaded opening is there.

[nightfisher]

The latest version of this scope has an SCT thread so maybe moonlight would change the focuser

[damnut]

I beleieve that Astrotec has a replacement flange. http://www.astrotecuk.co.uk/contact%20us.html

[Jose Auger]

This telescope IS the latest version. I just bought it new from Telescope Express in Germany (Telescope Service), exactly six days ago. That is why I am puzzled. And that is why I am asking if somebody knows or has the same telescope and knows if that flange can be safely removed and, probably, the 2 inch thread is under it. Up to now I have not dared to screw it off. First, it is extremely tight. I am going to need one of my tools to unscrew it. Second, I am wondering if it is holding something like the tube where the mirror moves in and out. I don't know and I do not want to risk damaging the telescope. So, if anybody out there knows, I shall appreciate your help.

[nightfisher]

I think if you remove the this thread it will cause the mirror tube to release

[Steve Ward]

Graham has started up production of the adapters again , he's the man to sort you out ... 

http://www.astronomyshed.co.uk/forum/viewtopic.php?f=102&t=24673

[Avocette]

It seems that there have been three different thread sizes over the years. My Mak has a 66mm thread, and I have a 66mm to 50mm adapter ring to fit a Revelation Astro SCT-fit Crayford focuser. But some (perhaps earlier?) Maks had a 48mm thread and FLO used to sell an adapter ring for the 48mm to 50mm SCT thread [dimensions of threads are to the nearest mm].

My scope, bought Nth hand, already had the adapter in place. I was determined to remove it to get back to basics and use the original 2" visual back. To do so I had to buy a fabric belt tool used in car garages for removing oil filters.

[Jose Auger]

This is a clearer image of the flange. If you zoom in the image you will see the thread.

[Jose Auger]

BTW, the adapters Steve mentions REDUCE the size of the MAK thread. My problem is contrary. The thread of the MAK is smaller than that of the Moonlite.

[Avocette]

Can you just check with a mm rule? The newest version should measure around 50mm, if your new Mak has a 48mm thread then it could still be new (unused) stock but which has been held for a while by the wholesalers. The first stories about the new SCT-compatible threads on the latest SW Maks were mentioned in early 2014, but a number of buyers were still reporting that they received the non-SCT version for a further year or so. The SGL Sponsor Dealer FLO has this on its website captured today:

[Jose Auger]

Here is the photo with millimeters measurement. It is around 35mm, not 48 or 50, with the flange in place.

[Jose Auger]

Here is a photo with the tube that holds the star diagonal in place.

[Jose Auger]

Here is the photo of the tube that holds the star diagonal.

[Avocette]

Oh boy - yet another thread size! But it's just possible that the ~50mm SCT thread you are looking for is hidden behind an adapter which connects into the supplied 2" 'visual back' into which the star diagonal fits. The photo where your wooden ruler is measuring the thread suggests that there is a further metal ring with a built in finger grip just waiting to be removed. It may need a bit of grunt to get it to move!

[Jose Auger]

Yes Avocette, that was the question I asked from the beginning of this thread. That is, if that flange can be removed. Well apparently it can. I just received an answer from the retailer from which I bought the telescope: Teskop Service, Germany. They tell me that in order to have an SCT connection I have to remove everything, including this last flange. Tonight I shall try it and hope for the best. Will keep you posted.

[Jose Auger]

MOONLITE SERENADE.... Success!!! Removed the flange. Had to use one of my largest wrenches to remove it and use a lot of force. Here are the results. Truly, the Moonlite is a work of art. No doubt about it. Now, waiting for the weekend to try it. However, we are experiencing pollution from Sahara dust (yes, it gets to the Caribbean and its nasty). Hope at least a decent seeing.

[nightfisher]

Excellent, glad you have found a solution