SBIG FW8-STL

8-Position Filter Wheel

 

 

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In August 2011, I decided to upgrade my optical train. The initial upgrade was to be the FW8-STL, an 8-position computer-controlled filter wheel which replaces the internal 5-position filter wheel in the STL-11000M camera; this would allow me to move to full narrowband images - Ha, OIII, SII as well as the normal L, R, G, and B (so 7 filters are required in total).

The SBIG FW8-STL filter wheel attaches to the STL-series cameras, enabling automatic control of up to 8 filters (2" unmounted or 48mm threaded). The faceplate of the STL camera - which contains the 5-position filter wheel - is first removed, and the FW8 attached to the front of the STL. The STL nosepiece mounting plate is removed from the faceplate and attached to the FW8, so that the same accessories that attached to the STL camera can now be attached to the FW8 (via a 2.1" 24tpi thread).

Instructions for the SBIG FW8 filter wheel can be found here.

 

At right, you can see the back of the STL-11K camera, and the FW8 filter wheel mounted to the front of the STL (here, the AO-L is already attached to the FW8, and can be seen to the far left).

 

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FW8 Connectors
At left, you can see the connector panel of the FW8-STL filter wheel. The I2C IN port usually has a cable extending from it that attaches to the STL camera. The I2C Aux Out can be attached to the AO-L adaptive optics accessory. Although there is a Power connector, it is only used if the FW8 is operated in stand-alone mode (i.e., with a non-SBIG camera); when connected to the STL-series cameras, the FW8 obtains its power directly from the camera.
Here is a side view of the FW8 (light gray, just below the camera) attached to the STL-11000M camera (above the FW8) and the Astrodon MOAG (below the FW8).
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And here, the entire optical train is mounted to the back of the 12" LX200R scope. The FW8 filter wheel is the largest component. Note that the AO-L/MOAG/RGH assembly is mounted 180 degrees from its normal position - where the RGH would be pointing downward, extending below the FW8 in this image).
At right is an image of the FW8 filter wheel loaded with 8 filters. I have 'borrowed' this image, as I forgot to photography the internals of my FW8 loaded with filters. In my set-up, I only have a C (clear) filter, and not an L (luminance) filter. In the 8th position, I currently have my 'old' Custom Scientific Ha filter At upper right, you can see the motor which drives the filter carousel by means of a friction connection to a rubber ring on the outside of the carousel. At lower right, you can see the optical detector, which determines the 'home' position of the carousel. It is important to know the order of the loaded filters, so that the same order can be set in the camera control program (MaximDL).
FW8 internal