My original scope purchased back in 2016 was a C11 and CGEM DX Mount. I had promised myself that after retiring to the clear skies of the Central West of NSW, Australia, I would buy a decent sized telescope and the upcoming apparition of Mars in 2016 was the prompter. A year later I bought the Paramount MX+ and a C14 and housed them in a domed observatory at Wattle Flat. I had no idea of the journey I was about to take on planetary imaging over the next 5 years. Meanwhile, I took the C11 when travelling to star parties. Despite my devotion to planetary & lunar imaging, I had always wanted to get into deep sky and having Bortle 2 skies and  encouraged by my good friend Rodney Watters I bought a deep sky camera, the SBIG 16803. My ambition was to swap between planetary and deep sky regularly. However, the practicalities of needing to reshoot Flats on every change, eventually meant I stayed on deep sky during the new Moon period and did planetary when the Moon was about. The concept of pulling down my dso camera and going across to planetary, to find the seeing was mediocre and going back again before reshooting Flats is not very appealing. Planetary is opportunistic and an hour of clear skies can mean an opportunity to produce an image. However, when set up on dso, those opportunities were lost.
I therefore decided that at one stage I would need to separate the solar system and deep sky imaging set ups. One possibility was to do one or other on the front lawn on a tripod, setting up each time. Whilst a lot of people do that, my previous experience was not all that encouraging. Perhaps it is a different story if you have a lot of clear skies and predictable weather. Before I built the dome, I used to set up my C11 on a tripod. As those of you who do this now know, you never take the chance if the weather is at all suspect and despite rigorous attention to the forecast, there were countless times where I set up and was just about to start imaging when the clouds rolled in and I would have to pull it all down again. An observatory therefore massively improves productivity and prevents frustration. I also set up a weather station so I was able to remotely image or even go to bed in the knowledge that my kit was safe.
So having enjoyed the luxury of an observatory, I was loath to go back to manual set ups again. Clearly an option therefore was to build a 2nd observatory. I have the land, but that is no light undertaking. Nor is it cheap, by the time it is built, with concrete, electrics and infrastructure.
I therefore and finally considered the option of making use of my under-utilised C11 and mounting it side by side with the C14. The Paramount MX+ has a payload capacity of 45 kilos and so that was never going to be enough. Therefore I eventually bit the bullet and bought the Paramount ME II. Familiarity with the Software Bisque range and software was a big consideration and I am enjoying the benefits of that during commissioning.
The idea is to move the SBIG 16803 across to the C11 and dedicate it to deep sky. That frees the C14 for planetary and lunar imaging as well as visual observing. Importantly it obviates the need for lengthy change-overs. Having said all that, I do have the Hyperstar for the C14 and can do fast wide field deep sky when the planets are not about, or when a comet happens along.
Interestingly enough, although the C11 has only 60% of the light gathering area of the C14, it has a focal length of 2.79m compared to 3.91m  for the C14. It is therefore faster and that varies with the square of the ratio of the focal lengths. Therefore I will end up with a  20% higher signal with the C11. So what is the penalty? It is image scale which will go from 0.47 "/pxl to 0.67 "/pxl. That will only make a difference if the seeing is between 1.5" and 2", where I will miss out on the superior sampling with the C14. However, since the seeing is generally 2"+, I am hoping it is all upside.
I had to get new stainless steel plates made for the top of my pier to take the larger pier adaptor plate. See Revision B
There was also significant work in balancing the two OTAs across the side by side plate adaptor. The C11 was a particular issue, with the 5+ kilo SBIG and the primary mirror on one end and the tube rings dictating the position on the OTA over the top of the plate. In the end I had to get an extra 8 kilo counterweight made to allow it to balance. See Revision C.
It was a two person job to get it all mounted up on the pier. I worked out the payload was around 88 kilos. The tube rings and side by side plate added 22 kilos alone. I knew I would need a lot of counterweight and figured on 90 kilos. I changed the weight size that came with the Mount from 2 x 30lb to 2 x 40lb, but clearly needed more. I had these made locally to obviate the high cost of shipping weighty steel from the US. Unfortunately, the weight was not quite enough!! I had a machinist make me up a 9" counterweight extension shaft and that gave me ample scope for balancing. See Revision D.
I had some interesting fun, trying to determine the right dome geometry parameters to go into TheSkyX Dome Add-On, so that it knows which azimuth to use when the scope(s) are pointing to given RA-Dec coordinates. I can set up parameters for each OTA, but I also defined a virtual scope, which has a diameter and centre line such that both OTAs are encompassed. This should allow me to have one set of parameters rather than multiple. The opening is only 1m across, whilst both OTAs are about 0.8m across, so the measurements have to be right to ensure both OTAs are pointing to space and not the inside of the dome. I validated that it works across a wide range of pointing positions in the sky.
I have collimated both OTAs and ran TPoint calibrations where the RMS pointing error was only 7-9 arc secs and significantly better than I ever achieved with the PMX+ at ~ 20 arc secs.
Next I need to check the set back spacing for the SBIG 16803 on the C11 to see if there is any field curvature. Theoretically it should be the same as the C14, but any minute differences in dimension can make a difference so I expect to have to make adjustments. I also have to perform PEC training. My one and only attempt so far is suggesting that TheSkyX software isn't giving the right result for the Southern Hemisphere. This is often problem when setting up equipment made in the Northern Hemisphere. Hopefully that is easily resolved.
This has been a huge project and quite expensive, but will hopefully set me up well for the future and improve my productivity for when the skies finally clear.