Ok here we go, just so you know what to do with the RC8, QSI and SSAG.
The RC8 has a big and small extension only in the imaging train with the feather touch focusor I bought. Next on the QSI I use the metal spacer that goes in between the blue and black body segments. If you do this the SSAG will come to focus. I use around 3 second exposures but only because I have good seeing there and a PME; 2 seconds is fine should be fine on your setup.
You need to ensure you focus the main camera first. Don't focus the guide camera first and then the main camera. It will not work. I use the spacer on all my telescopes and it works fine. I have only had to focus the guide camera once and now each time I just focus the main camera and the guide camera is also ready to go. Using a flattener or reducer helps too. I found that the stars on the edge of the field on the RC8 were really elongated and this affected my guiding. That is because the guiding software cannot determine where the center of the mass is and this makes for erratic guide corrections. Roundish stars are better.
If you follow this I promise you will have this working in no time.
