I was going to post this in the ATM forum but thought it would be better here. Well I have had this filterwheel and a QHY9 for a while now and two things really bothered me. Firstly was the M54 thread in the FW casing. This is not good for adaptors unless you want to use Baader M54 - T2 couplings (causes vignetting). Secondly the supplied nose piece has the M48 thread cut on the wrong side making it impossible to fit reducers etc(Theo is getting some new ones). If you have one don't panic for the fix is really easy and better then you may think. All you need is a hacksaw and file though access to a lathe is better and this is how I did it. If you cut off the 2" nosepiece back to the flange the M48 threads are exposed. Simply clean up the face with a file or lathe and you have yourself a 1mm thick (when fitted) M54 - M48 adapter. This allows all the normal bits and pieces to be added and it only adds 1mm of back focus. I have a number of 2" WO diagonals around which are converted to SCT threads so their 2" nosepieces are redundant. These screw straight into the modifed adapter and they have the M48 thread cut on the right side. Any nose piece with a M48 thread will fit though.
Pic 1 & 2 - The offending QHY nosepiece notice where the filter thread is.
pic 3 & 4 - Thats one slim adaptor but still has 5 mm thread to screw in M48 threads.
pic 5 - fitted to FW, only 1mm proud so does not affect backfocus.
pic 6- with WO 2" nosepiece.
pic 7 - TS-OAG- 9 mounted (48mm threads = no more vignetting)
pic 8 - All together with the TS field flattener attached (for refractor). It is a simple screw out the TS FF and Screw in the AP CCDT67 reducer (with spacer) for The LX200 as both have the same distance requirements to the chip and are almost identical
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Cheers
Mark