I wanted to build a simple and cost-effective (i.e. "cheap") light box for my model photography. I searched the web and found several sites referencing 1/2" PVC piping. That seemed like the right solution. Using the materials listed on this web site, I set off to my local Lowe's (plumbing department) and bought the necessary parts. The prices on the site are a bit outdated. I also didn't buy the screws. In retrospect, I wouldn't buy the glue either. See below as to why. I cut the tubing approximately to the lengths stated on the web site. The sizes are really just whatever you want the lightbox to be. If you photograph tall items, then you'll need to make the legs longer. I restricted the size of the width and depth of the light box based on the table upon which I want to set the light box. The first photo shows the cap used for the legs, and the 90-degree street elbow to connect the legs to the rest of the frame.
The tees are used to build the main frame. It connects the width and depth tubes together. The 90-degree street elbow connects to the remaining opening on the tee. Note that the referenced web site tells you to clean the burrs off of the tubes, but I found no need for doing that. I used a hand saw to cut the tubing to length.
The next photo shows the basic parts. The main frame has been put together. The legs each have their end caps (to be used as feet), and the 90-degree elbows installed.
And here's the entire lightbox put together. I decided not to use the glue, because the parts are held together plenty using friction. As you can see, the lightbox can be quite large and bulky. By leaving the parts loose, I can take it all apart and put it neatly away without taking up a lot of space.
To actually use the lightbox. I temporarily clamp a sheet of white poster board to the back of the lightbox. The poster board is normally rolled up when I store it, so has a tendency to curl. I place some metal weights on the front corners to control the poster board.
I bought a twin white bed sheet at Target as my cover. This was the most expensive part of the project, but I didn't want to use a bed sheet we actually use in our beds. I drape the sheet over the light box and the camera. My camera comes with a wireless remote control and so I can control the camera remotely through the sheet. This completely manipulates the lighting inside the light box. For lighting I use two halogen lights, each one placed slightly toward the front of the target model.
One photo taken with this set up is shown next. What the white sheet does is completely hide any harsh shadows. Note how the shadows under the car are very subtle. It has good overall lighting, with no spotlight effect. For reference, the model is about three and a quarter inches long (8.25cm).