I am looking into this...
3/16 X 24" Threaded stock, toggle bolts to fasten to ceiling. A scrap piece of mdf, center cut out to expose projector top panel, 3-4 rubber feet. Whole project will cost about $10. All available from HD.
Assemble and place projector upside down on mdf.
Variation two. attach projector to mdf, attach mdf to ceiling using threaded stock. secure and level everything with a couple nuts / washers. Cost will be a few dollars more to pick up additional hardware. Should provide a more secure attachment.
jd...