What is the purpose of the Starlight Instruments 3.5" End Cap with 2.0"-24TPI threads?
This end cap is designed to create a secure, rigid, threaded connection between a 3.5" Starlight Instruments Feather Touch focuser and specific astrophotography equipment from Finger Lakes Instrumentation (FLI). It replaces standard compression-ring end caps to prevent equipment sag or tilt.
Which specific FLI products is this 3.5" End Cap designed for?
This end cap is specifically designed for a direct threaded connection to the FLI CFW2-7 filter wheel and the FLI Proline 16803 CCD camera. Check your equipment's documentation to confirm it accepts a male 2.0"-24TPI thread.
I have a 3.5" Feather Touch focuser on my large refractor and an FLI Proline 16803 camera. Is this the correct adapter?
Yes, this is the exact component you need. It will allow you to thread your FLI Proline 16803 camera directly onto the drawtube of your 3.5" Feather Touch focuser, creating the most stable and orthogonal connection possible for your imaging train.
Why should I use this threaded Starlight Instruments End Cap instead of a standard 2" compression ring adapter?
A standard 2" compression ring holds equipment in place with a set screw and a soft brass ring. While fine for visual eyepieces, this can allow a heavy camera and filter wheel to tilt or shift slightly, ruining optical alignment. A threaded connection, like the one this end cap provides, locks the components together as a single unit, completely eliminating this risk.
How do I install this 3.5" End Cap on my Feather Touch focuser?
Installation is straightforward. You simply unthread the existing end cap (typically held on by three small set screws or a threaded collar) from the end of your 3.5" Feather Touch focuser's drawtube and thread this new end cap in its place. Ensure any set screws are properly tightened to secure the cap.
If I'm building an imaging train with an FLI CFW2-7 filter wheel on my custom Newtonian with a 3.5" Feather Touch, will this provide a secure connection?
Absolutely. This end cap is the ideal solution for that setup. It ensures that your filter wheel is rigidly attached to the focuser, which is critical on a Newtonian where the focuser is often oriented sideways, maximizing the force of gravity on the imaging train.
