The Muscle Plate

John Smith and I have designed a new cover plate for the CFW8 that is much stronger, and has some additional features, that many SBIG product users  have been looking for. We call it the "Muscle Plate" and it's a cover plate on steroids.<G>  Like the Mandel Wide Field Adapter for Nikon Lenses, it simply replaces the standard CFW8 cover and adds some very desirable features. Potential flexure of the original cover plate, which can lead to image movement, erratic filter wheel operation, and loosening of the T-thread adapter is eliminated.
                                                                           Muscle Plate (left, unanodized prototype) and original cover plate
Muscle Plate features:

Note: The Muscle Plate changes the back focus requirements.  For non-AO-7 users, the back focus requirement is increased by 0.19"; for AO-7 use, the back focus
requirement is reduced  by 0.14".
  • Note the increased thickness, about 4x, where the plate, and therefore either the AO-7 or any other T-thread accessory,  attaches. This insures the plate does not flex or move due to the off-axis load, represented by the camera, filter wheel, etc.
  • A set screw, indicated by the Allen wrench on the MP, guarantees a secure mount of the T-thread adapter, while the standard plate depends only on the friction of the hand-tightened T-thread adapter.
  • Note how it is possible for a T-thread adapter, in this case the one from the captain's wheel of the AO-7, to intrude into the filter wheel space.  This can  interfere with filter wheel rotation.  The additional thickness of the MP prevents this from happening.
Edge comparison of Muscle Plate and original plate

The Muscle Plate sales for $125, and is now exclusively available through Anacortes Telescope.
Please call them at 800-851-2001 or click on the link to go to their web site.