Sure you can buy one just like it in the store but PVC pipe is fun to build with.
Step 1: The Bag
The bags are sturdy cotton and are roughly 32 inches long and 27 inches wide. They have a drawstring in the top and a little spring loaded barrel tie. They're nothing fancy.
If you were to make these, you would need 2 panels 35 inches long and 28 inches wide. You would sew both panels together around 3 sides approximately 1/2 inch in from the edge leaving ond of the 28 inch sides open. You would then fold the edges of the open side down 2 1/2 inches and sew around the circumfrence of the opening 1/2 inch in from the edge of the fabric (2 inches in from the fold if you are so inclined. After that you turn the whole thing inside out and cut a little hole to thread your drawstring through and get to threading.
Step 2: The Frame
You will need the following pieces of pipe and fittings:
8 1/2 inch T Fittings
8 1/2 inch 90 Elbows
4 15 1/2 inch long pieces of 1/2 inch pipe
4 13 1/2 inch long pieces of 1/2 inch pipe
4 7 1/2 inch long pieces of 1/2 inch pipe
8 3 1/2 inch long pieces of 1/2 inch pipe
I added labels to the image to show which pieces go where. The fittings are obvious as are most of the pieces. The 15 1/2 is the vertical piece and the 13 1/2 is the horizontal piece.
I made the circumfrence of my frame at the top a bit smaller than the circumfrence of the opening of my laundry bag so that I could fold the top of the bag over the top of the frame to secure it.
I also made the frame a bit shorter than my laundry bag so that the bag actually sits on the ground and is not suspended from the frame. This keeps the bag opening on the frame. Were it suspended the bag would just pull from the frame and wind up on the ground. You may need to adjust the dimensions of your frame if your laundry bag is significantly larger or smaller than mine. When making your adjustments, remember to account for the length your fittings add.
The wide side of the frame has a large opening. When the laundry bag is full, I want to be able to pull it out of the frame. With the side supports up high and low, it leaves me alot of room to pull the bag right out of the frame.
Step 3: The Finished Product and Tips
Here are both of my hampers. They took about 30 minutes to build while chatting and sitting on the garage floor with my dad and my dog. Without a dog, your build time my vary.
If you don't have a PVC pipe cutter you should buy one. Mine was $10 bucks. Even if you aren't doing any irrigation, PVC pipe is just plain fun to build stuff with. I'm sure you're already thinking of other stuff you can build. A cutter will make your builds more fun and easier.
I didn't glue anything. I may go back and do that later if a joint pops open. I did use a dead blow mallet to pound things together a little.
I noticed my two frames didn't look exactly the same though the cuts were. A little difference is to be expected because PVC fittings aren't perfect but I was off by a vary noticable amount. A couple gentle taps from my mallet made all the joints snug and made the frames look much closer to eachother in dimension.