Astro-Physics Right-Angle Polar Alignment Scope Adapter for 900 Mounts
The Astro-Physics Right-Angle Polar Alignment Scope can be used with the AP 900 Mount when used with the appropriate mount adapter. Each mount will require its own adapter, and if you have another AP mount (Mach1 or 1200), you will need an adapter for that mount as well. It is important to note that the adapters will add some dimension to the back of your mount which, if you have a carry case, will require a small modification to the foam liner.
The RAPAS 900 adapter is push/pull adjustable for precise alignment. Once adjusted, it will retain their precision, allowing the polar alignment scope to be inserted and removed as needed (the adapter, itself, remains attached to the mount). This will also allow the polar scope to be used interchangeably with each of your mounts without further adjustment. The adapter's alignment is what allows this precision polar alignment scope to provide consistent accuracy when re-installed repeatedly with either a single mount or when used with many different mounts.
In order to obtain extreme precision, it will be necessary to perform a precise polar alignment using a traditional drift alignment (visually or with CCD camera), or by using Ray Gralak's PEMPro / Polar Align Wizard the first time that the RAPAS is used. Once the alignment is spot-on, the push/pull adjustment screws on the adapter are used to orient Polaris into its specific location on the reticle.