Get and keep everything clean, including the back of your fabric. When you roll up the screen, the back touches the front, and any dirt will transfer right into the middle of your new screen.

Take the actuator arm off the wiper motor. See what the threads are. (take that nut to the hardware store)

The threads on mine were metric something or other, and I had everything for the 5/16 threaded rod setup, so I very carefully welded the rod directly to the motor output. This is very hard to get right and I wouldn't recommend it.

If you could find metric coupler nuts, that would be a better route as later you could then attach to the motor with just that and tighten the threaded rod into the coupler, jamming against the end of the motor shaft. Make sure that whatever direction you pick for your screen to roll up, the motor is on the appropriate end to tighten this joint when you pull down on the screen fabric, or you will regret it. Just dry fit the parts for now. You'll need the rod separate to make the roller for the screen.

Keeping the screen tensioned is what keeps it flat. I provided the needed tension almost all in the vertical axis with weight.

Take a scrap of your screen fabric, and test how hot you can get an iron on it, before it melts. Three layers, and two are plastic remember. Back off from that temp a little. Hot as you can go without melting or distorting, is what you want.

Wrap the fabric around your conduit. Mark where it comes to. Add the width of your fusing tape and like 1/4 in. Mark this line across. Remove the conduit.

Apply your self-adhesive fusing tape along this line. Fold the edge over to meet it. Now tear it all apart and flip it over so your seam is on the back. :)

Iron the ends, then the middle, then between that at even intervals, until you run out of intervals.  Then iron all the way across. 

Do not slide or move the iron at all while pressing down as it will cause the tape to 'migrate' while it is hot. Press, lift, move, press...

The light block fabric is actually three layers. White on both sides, with black plastic in between, but you are still painting fabric so you may have to experiment to get it right.

Lay your light block fabric out on some hard clean surface. Don't step on it, don't press on it, don't fold at all except to mark off your projector's aspect ratio in pencil, centered, leaving room for one wrap extra at the top to stay on the chain link fence post in the down position. The extra wrap does wonders. Trust me.

Taping your fabric to the floor outside the view-able area helps greatly. Don't tension it.

Tape off your viewing area. Completely cover the center with newspaper, tape that down at all joints too. Any over-spray is very noticeable. Paint the border with the black camo (better) or flat black paint. Take your time, light coats. Let it dry. Wipe the finished paint lightly with a towel to remove any residual over-spray.

Too much paint thickness on the edges, will actually make your finished screen wrinkle in the middle. The edges 'roll up faster' than the middle does from the thickness of the paint! If that happens, reverse your taping and paint the middle flat white in equal amounts. (this has the added benefit that you can touch up any stains, kid's markers, etc with the same flat white paint, and the opposite is not true. Painting too thickly in the middle will not wrinkle your edges. The latest version actually got re-painted with exterior house latex (to cover some marker drawings) as I was out of enamel, and actually exhibits the best behavior I've had to date.

Cut your fence post a few inches longer than your screen width. Deburr the edges, inside being just as important.

Make 2 hardwood, Lexan, or acrylic blocks to plug the ends and accept your threaded rod. Being centered and true is important, or your whole mess will wobble as the screen goes up/down and muck up the works.

Start with a 2 1/4 - 2 1/2 in hole saw Thread your rod directly into the 1/4in hole left by the hole saw if you are using Lexan (or actually tap it out for Acrylic/hardwood). Easy way to get this perfect is put the threaded rod in the drill press, and manually spin the spindle while pressing the rod into the hole.

Put jam nuts on both sides. Put the rod back in the drill press. Turn up the rpm's and work it with coarse sand paper until it almost fits inside the fence post. Remove the inner jam nut, or better yet glue it in place with some epoxy Make sure you can get the rod back out.. For Lexan/hardwood, leave it a bit over-sized and press it into the fence post. I used a hydraulic jack for this. Use your imagination.. Perfectly centered and true.

Remove the threaded rod. Clean the finished post, well. Clean it again.

Get help. Clean yourself. Clean the floor. Wash your hands often.

Look for the weld line on the post, or otherwise establish a line along it's length. Line up your fabric with this line, and tape across the joint, applying slight tension the the fabric. With some clear packaging tape, tape the screen to the pipe keeping it on that line. Roll it up and see how badly it tracks one way or the other. Repeat, until it rolls up and doesn't wander more than about 1/4 in when you do it. This will take some time. It doesn't have to be perfect, you'll trim it later... but your viewing area will be crooked if you don't get this close.

Once you have the fabric rolling up straight, unroll it all the way + carefully 1/2 turn more so the tape is now folded over on itself and a narrow bit of it's adhesive is showing. Add another strip of tape to the pipe, and another strip of tape to the underside of the fabric, so you end up with an inch wide strip of bare metal and fabric that when you roll it back up, the tape will unfold and they will meet.

Lightly and evenly coat the exposed area (the back of the fabric, and the pipe where it will land) with contact cement. Spray contact cement obviously works best here. Follow the instructions, letting it dry a few minutes. Lightly tension the fabric at both ends, and turn the pipe to now roll the two areas together. You won't get a second shot at this as pulling the fabric off of the contact cement will stretch it, making it unusable and you likely don't have enough left to cut it off. This is where you end up using your backup piece of fabric.

Congrats. That was the hardest part.

Roll it up neatly. Tape all the way along the bottom seam (with frog tape) to keep it rolled up tight. Wrap some paper around it to keep it clean. Tape that on too.

Drill two holes, almost all the way through, two blocks of something the same size as the outer diameter of your roller blade bearings. It's a common size like 3/4 or 7/8in. Make them identical. For the hole you are after, you need a nut on the threaded rod to clear the inside of the hole, but the outer lip of the bearing to still hit it.

Take your other coupler nut, and fashion a small post coming off of it at a 90 degree angle. I welded mine. Take your corner brace, and make a second post behind the first, the thickness of the corner brace, so the main post slides on the front, and the smaller one slides on the back of the corner brace.

Screw the new coupler onto the threaded rod attached to the motor.

Take the corner brace, and attach it to the motor, with the flat surface parallel to and even with the threaded rod.

Run the motor a tiny bit. If run it until the rotating coupler nut hits the one fixed to the motor shaft, it will eat itself or tear a hole in your hand. Figure out which direction the nut will move when the screen goes down/up if you wind one way versus the other.. I wound it with the screen closer to the wall, as in my case it also covers 3 windows as it goes down and the closer to the wall, the better. Make sure your post moves freely along the corner brace. Run the motor until you are in the 'upper' position. Line up where your switch needs to go, mount it to the corner brace only by the back screw hole.

Remove the coupler-post nut.

Assemble the motor - bearings - roller, washers etc.. and put it up on the wall.

Run the motor in the 'screen up' direction. Take a brand new, sharp razor knife and hold it against un-even ends of the rolled up fabric. Make sure the direction of travel of the material is going away from you, so the knife does't bind in the cut and stab you.. Light pressure will eventually cut down to the steel, trimming the edge of the screen perfectly.

The relay coil is driven by 'remote power' output on the projector. There are no other connections made to the coil. As such, this also performs the needed isolation so if you screw up anything else, you at least don't fry your projector. The projector supplies 12v and mine outputs about 200ma or so according to the manual.

The paranoid could also put a diode in reverse across the relay coil to prevent the emf kickback, but I left it out intentionally as 'relay coil to projector' is more idiot proof.

The DPDT relay is wired as a reversing switch, with the crossover wiring part attached to the motor input, and one leg of the reversing crossover wired through each roller switch in the NC position. The NO connection of the roller switches then get wired to the opposite leg of the power input. When the screen hits either limit, power is cut, and the motor is shorted. The relay entering the opposite state is NOT shorted however and the motor will then travel to the other limit.

I'll post a schematic when I can look at it. EDIT: it was a blob of wires and epoxy when I finally took it down to move.  Not so easy to reverse engineer what I did.  I'll generate it from scratch again when I get the time.

Put it up on the wall and level it.  One day in the sun will remove any wrinkles, or careful application of a hair dryer will do the same.  Don't overheat it as the plastic inside can expand and ruin it.

Tweak the stop positions.  Applying the 12v to the relay coils here with a switch here is a lot more convenient than using the projector to do it.  Just keep the two separate while you are doing it.

Build a nice valence in front of it.

Enjoy your new screen.

Like this project.  :)