For what itâ€™s worth, I just mounted a G11 on a 6" X 6" beam in my cathedral ceiling family room last weekend. I used three heavy duty "L" brackets I purchased for Home Depot. I temporarily mounted the projector to the beam and aligned it horizontally to the screen. I drilled enough holes in the bracket so I could elongate them (front to back slot) This gave me about an inch and a half front to back movement so I could dial in the image size on my 100â€™ 3 X 4 screen.
The hardest part of the whole installation was finding metric threaded rods. http://www.avsforum.com/ubb/frown.gif
The front and rear left (when inverted) foot holes are 8mm course thread. I was finally able to get an 8mm (very close to 5/16") treaded rod at a specialty hardware store. The other foot threaded hole is 5mm, which is approximately 3/16". This threaded rod or long threaded bolt I couldnâ€™t find. So I purchased a standard 3/16 threaded rod and rethreaded the length to go into the projector to 5mm. The set up is worked fine.
I locked the rod into the projector foot hole with a large fender washer (big washer with a small hole) and a nut. I then put the projector and threaded rods up through the "L" bracket, adjusted and the tightened nuts and washers to the bottom and top side of the bracket.
The beauty of the set up is that it gives total projector leveling and tilt control. I had to up angle the front of the projector by about a degree and a half to align to the top edge with my screen. This little adjustment, surpassingly didnâ€™t cause any noticeable trapezoidal effect. http://www.avsforum.com/ubb/biggrin.gif