You might want to wait until you've projected an image before you install the mount. Keep in mind the height of the screen will be the limiting factor, if you don't want your center channel in the image.
Just saw your post from yesterday.
That's why I want to mount onto a 'track'. I can attach the mount directly to start and have the flexibility to move the projector side to side depending on screen size. I can also add an extender if needed when I know what the exact screen size is. I did already measure based on the largest screen size.
I have a foot above the screen and two feet below at 123" diagonal. That will allow me to just fit the top center (11.5") at the largest screen size. The bottom center will not be an issue.
Fred
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