Starlight Instruments 2.0" Adapter for Borg M57

This adapter's sole purpose is to mechanically connect a Starlight Instruments 2.0" Feather Touch focuser to a Borg telescope that has a female M57 thread port. It allows you to upgrade your Borg system with a high-precision, robust focuser.

This adapter is designed for Starlight Instruments' 2.0" Feather Touch focusers, both Crayford and rack-and-pinion models. It utilizes the focuser body's 69x0.75mm female thread for attachment.

The adapter has two distinct threads:

• Focuser Side: Male 69mm x 0.75mm thread pitch.
• Telescope Side: Interfaces with the female M57 threads on a Borg telescope.

The 0.475" (12.065mm) length of the adapter becomes part of your total back focus distance. You must account for this length when calculating the spacing for field flatteners or focal reducers. While it provides the necessary mechanical connection, it also consumes that much of your telescope's available back focus.

This adapter provides the correct mechanical connection between the focuser and a Borg telescope with an M57 port. However, you must also ensure that your complete imaging train (focuser, adapter, camera, etc.) does not exceed the total back focus available on your Borg 71FL. Always verify your specific optical configuration's spacing requirements.

Upgrading to a Feather Touch focuser offers significant advantages, especially for astrophotography. You get extremely fine focus control from the 10:1 reduction knob, zero image shift when changing focus direction, and a robust design that can handle heavy camera and filter wheel combinations without flexure or slippage.