Hi,
I think I should share my experiences with Vixen Sphinx mounts. I bought my first telescope two years ago and very soon started thinking about astrophotography. It took me some time to buy all the bits and pieces, and then there was a big disappointment. Not only the mount (Sphinx SXW) was noisy (sometimes I thought it would fall apart) but guiding in the declination practically did not exist. There was a constant drift in one direction and then a sudden jump in the opposite direction. I have tried to identify the problem - too much load, lack of balance, dragging cables. I spent countless hours while browsing this and other astronomy sites. I even suspected my neighbour's black cat
who was constantly observing me from the balcony above, probably attracted by the grinding noise coming from the mount. I knew about problems many guys had had with this mount but at the same time I saw quite many good images taken using it. Finally, someone advised me to get a better model of Sphinx - SXD. After spending all the money on other equipment, I was so desperate that I ordered it.
By the time I received the new mount, I found the information about the NexSXD motor control produced by a MGAstro in Spain. It replaces the original board in the mount and uses NexStar protocol. It can be controlled using either NexRemote software or CGE-Pro hand controller. I had nothing to loose with the old mount, so why not to modify it. I received the new board and installed it without any problems. First, I thought that it did not work. I could not here any noise from the mount - absolutely nothing. Well, it worked. After few minutes I saw that the mount was moving along the RA axis. I was so eager to give it a try that I did not bother with proper alignment, balance, or correct focus. Just in case, I checked for the cat. She was not there
. I started guiding and taking images of Centaurus A. I did not manage to take too many images because of the clouds but enough to see that the new board worked. The image is attached below. It is far from being perfect or even good but for me was fine.
The new mount SXD arrived, the problem in the declination axis still existed, and the mount was even noisier, so I immediately ordered another NexSXD board (they are a little different for both SXW and SXD). It arrived very quickly, no problems with installation, no more noise. Will it work? This time I took a little more time with balancing, alignment, etc, probably not enough time. The moon was almost full but I didn't care - there is a lot of light pollution from the surrounding block of units and car dealerships anyway. I was more than happy with the resulting images (Omega Centauri and M20). Then, there was cloudy for some time. Last week I took the image of M8 and was so happy that finally, after more than a year of struggling with the mount, things started to work, at least I hope so.
If someone needs more information about NexSXD, here is the link to their site:
http://www.telefonica.net/web2/amalt...NexSXD_eng.htm
Cheers,
Matt