I would love to use this:

But with the dimension constraints I cant get a linear actuator big enough to fit in there and get the total movement I need. So on to the specifics:

Projector: Epson 6500UB

Dimensions of Projector: (W x D x H) 17.7" x 15.5" x 5.4"

Weight: 16.5

Estimate weight of projecter+enclosure: 40 lbs

Dimensions of space in ceiling: (W x D x H) ANY x 17" x 10"

The depth is 10" from the top of the cut-out in the ceiling down to the bottom of the drywall, so anything I make has to account for 1/2" to 3/4" of drywall that would have to be installed on the bottom of the enclosure.

I need the projector to move up/down approximately 15". There is a $100 linear actuator that can handle 400lbs and move 18" and I was looking at that as my starting point ( http://www.firgelliauto.com/product_...products_id=56 )

Due to the 17" depth dimension and 10" height dimension constraint I am thinking of doing a cable/pulley system, a linear actuator and an enclosure on rails or with round alignment pipes to keep it from spinning. Something like this:

But with the actuator mounted sideways:

And thats kind of where I am at now. I would love to do a simple scissor lift, but I am having a hard time envisioning it. I have looked at the 80/20 website and again, having a hard time really seeing how I could use the 80/20 parts. They look simple and easy, but with my constraints I dont think I can really utilize the 80/20 method. Any help is greatly appreciated!