Step 1: Design It
My pool is about 11 feet wide. I used a total of 10 feet of pipe. The additional tees make the entire width about 10 feet and 6 inches wide.
Here's the equipment I used:
10 1/2" slip caps (0.25c each)
2 1/2" 4-way cross ($1.00 each)
2 1/2" 3-way tee ($0.80 each)
4 1/2" top threaded tee ($0.80)
4 1/2" threaded male adapter ($0.60 each)
3 10ft 1/2" PVC pipe ($2.00 each)
Net (use an old badminton net or this one from Walmart for $20 and cut to size )
50' nylon string ($3)
Plastic spray paint ($5 optional)
2 Foam Noodles ($3 each)
Beach Ball ($3)
Total Cost: ~$45
PVC cutter ($14)
Face Mask ($1)
PVC cement ($5)
You'll also need something to debur the PVC after it's cut. I used a dremel. You can use sandpaper, but that'll be tiring.
Step 2: Build It: Cutting the Pipes
Once you're done cutting, you'll need to debur the cut ends. You can use sandpaper or a dremel. Wear a mask while while you're doing this as the PVC particles can be hazardous.
Cut the noodles to size. Make them a little longer than the pipe that you plan on putting them on. You can always cut more off later.
Step 3: Build It: Assemble It
Assemble the frame. Make sure you have all the pieces and everything fits. Once you're sure that everything is ready to be permantly fixed, disassemble everything.
Put on the mask again and apply the PVC pipe cement to the inner ring of the tee and connect the the PVC pipe. Don't waste time because the cement starts drying quickly and the pipe may be hard to position. Of course, do not cement the threaded ends.
Once you have everything assembled, you can paint it with plastic enamel spray paint (optional). Leave it out to dry for a day.
Step 4: Build It: the Net
I used nylon string to make the top, bottom, and sides more ridged and cable ties to tie the string to the net.
On the top PVC caps, I drilled a small hole to run the string through. The top PVC caps are not glued to the frame to allow easy removal of the net when necessary.
Step 5: Putting It All Together
Tighten the net. Now, just find some way to tie it down in the pool so it doesn't float away. I have a string running to a pipe in the spa and a string running to the filter trap on the opposite side. It worked quite well.
That's it! Enjoy! It's pretty stable and only tipped over two or 3x during our games.
Things to improve it:
1. Find a better way to fix it's position so it doesn't float around. I thought about creating a spring loaded device to press against the side walls, I just didn't have the time. It should be pretty simple to make.
2. Prevent flex from the tight net. I have three possible solutions.
a. The preferred way would probably be to use parellel pipes for the 10 foot span. That should make it more ridged and lower it's center of gravity to prevent tip overs.
b. Use a solid bar through the middle of the pipe and through the verticals. This will also lower the center of gravity, though it'll make it unnecessarily heavier.
c. Use a thicker pipe for the verticals and 10 foot span.