[billdan (Bill)]

Just to complete this thread and give you my experience of getting everything working. I had the flu and clouds etc, so I only got started last night. Still took me 3 hours to figure it all out.

Problem No.1 When I screwed the 18mm spacer between the QHY12 and OAG, the prism was sitting on the RHS corner of the QHY12 chip (which was useless IMO), so I created and printed off two 42mm washers 0.5mm thick and placed one on each end of the 18mm spacer. Now when its tightened down the prism is dead centre.

I also printed a 42mm washer 1mm thick and placed that on the MPCC T thread going into the OAG, this now gives me the exact 55mm as required for the MPCC to work correctly.

Problem No.2 As Bo said I also had to remove the 5mm tall side to side adjuster to get the lodestar to focus, but I replaced it with a plastic clone that I created and printed, I tried a 1mm, 1.5 and eventually a 2mm tall piece and that got me perfectly parfocal with both cameras.

I did a quick test last night.

The MPCC is behaving perfectly, round stars right into the corners, the only worry I have is the focus seems a bit soft compared to no MPCC. So I am keeping my fingers crossed that better collimation will cure this, which I'll try later this weekend.

What blew me away was the guiding, the best I have ever achieved with the Orion mini guidescope was 1.2 arcsec, but with the OAG I am now getting 0.55 arcsec guiding at 3sec exposures on the lodestar.

Cheers

Bill