Originally posted by davgiles
Yeah that pull down screen should make it easier. I was thinking in terms of a permanently mounted screen.
Well any setup will have one of the components yielding to the other. Either the projector will have to be mounted to align with the screen or vice versa. My setup design wants the image as low as possible, so I designed the mount to hold the projector just a couple inches over my head while standing underneath.( I'm the tallest in the house.) The mount is 15 inches of drop, the screen is a 92" wide 4:3 model that will have an extra 17" of material above the masked 16:9 area. The calculations of image offset with the projector upside down is approximately 2.875 inches above lens center. Without going in to all the specifics of the math, it looks like I'll have to roll the screen up somewhere between 2 and 6 inches, accounting for amount drop created by the screen housing itself (which I don't know yet, it hasn't arrived, should be here Mon-Tues
The bigger issue is the resolution of the ratchet mechanism in the retractor of the screen, if it locks at 2 inch or greater increments then I will most likely have to submit some "engineering changes" to make it line up vertically assuming one of those locked positions doesn't land perfectly in line with the image.
Besides, I'm a machinist, who do you think fixes all the mistakes made by those boys up in the engineering office at NASA?