Graham,
Photo of mine with everything on an AZ-EQ6. All up, it weighs somewhere around 18.6kg.
- Tube - 13kg (approx)
- Rings & 74mm Dovetail for Tube - 2.6kg (approx)
- Camera (7D with battery and card) - 1kg (approx)
- 80x400mm Guidescope (with rings, dovetail, extension tube and camera) - 2kg (approx)
In order to do this however, I need the extension bar that comes in the box and an additional 5kg counterweight to get balance.
Once you get balance, you can get the rings to be rotated in the correct spot that it then sits back in your dob mount without adjusting again.
Hope that helps you out.
Joel