Thanks again for your advice on my setup...one question: is your frame/screen the same one from the creativeshelters.com website (digitaldummies.com)? This is the same design I was intending on using, but was unsure as to whether or not it was a good price to pay for the kit or not.
I built the Creative Shelters/Digital Dummies (CS/DD) screen, too. I've used it for the last two years (this year will make three). I think it's well worth the money for a solid 10'x20' screen. Keep in mind, the EMT tubing you buy separately is going to cost about as much as the screen kit itself (if you buy the EMT from Home Depot or Lowes). All told, it still comes in at under $500. If you get a good deal on EMT you can likely keep it under $400.
Many have upgraded from the included vinyl tarp to either trapeze fabric or black out cloth. I'm sure those are improvements. I've been considering BOC as an upgrade this year myself. Right now I still run with the original tarp. I've not had the hot spot issues so often attributed to vinyl. I think the reason for this is two fold. First, the bottom of the screen surface sits about 5 feet off the ground. I fire my projector from a relatively low angle. I suspect the heaviest reflections (hot spots) are reflected upwards away from the viewing audience due to the angle of incidence. Second, the frame and bungees draw the vinyl evenly taught and flat. There's no wavy effect (like with a loose hanging tarp) creating multiple angles of incidence (where hot spots form) across the surface. If you buy the kit I'd say give the tarp a try. You can always upgrade
It sounds like hiredpower modified the dimensions on his build a bit to better fit a 16x9 ratio. Doing some quick math, and keeping the 10 foot height (EMT is sold in 10-foot lengths), you might consider reducing the width to 17.8 feet. However, if you're like me you won't mind the extra foot on each side. Plus, if you modify the frame size you'll need to source a different tarp or screen material as the one that comes in the kit will be too large.
One more thing I can say about the CS/DD design is that I don't agree with all of the EMT cut lengths supplied with the kit and on the DD site. Of course I didn't realize that until I cut the EMT to those lengths! It seems like I have to do too much adjusting back and forth in the fittings to get the frame lines straight. If the EMT was cut to the right length one could simply bottom out each insertion and be done with it. I took some meaurements of what I thought the cut lengths need to be. Then I did some trigonometry based on the angles of the fittings. My cut length estimates were almost dead on with the math. Thankfully, you actually cut only a small fraction of the EMT required. I think I'm going to pick up a few new 10-foot sticks of EMT and re-cut some of the lengths this year. If I do I'll post my cut length recommendations. Oh, and do invest in an inexpensive pipe cutter from Home Depot or similar. It's a lot easier than a hacksaw and the cuts look much more professional.