Houston Astronomical Society

I have an easy one. I was using my D5100 to take photos of the moon. When connected to a 2x Barlow I was able to focus perfectly on the moon, however without the Barlow I could not get the moon in focus, the focusing device was bottomed out, i.e. the camera was as close to the secondary mirror as possible but not fully in focus.

What attachment do I need to put between the secondary mirror on the scope and my camera in order to have a focused, full view of the moon?

Any help would be deeply appreciated.

Unfortunately not much can be done, other than checking around for a mod to move your primary mirror. In some cases it can be very simple.
https://www.youtube.com/watch?v=jDpSXPNCnS0