Turn Your Smartphone Into a Projector

If you’re looking for a way to engage your clients’ eyes and ears during a showing or listing presentation, consider this DIY projector as a video accompaniment to your Chromecast Audio setup as an economical solution. It may not be as luminous as other available options, but the price is considerably better, and the only electronics setup you have to worry about is getting the screen orientation and brightness correct.

What You’ll Need

 

This projector setup uses a lens from a magnifying glass to focus and project an image or video from your smartphone onto a wall. Here’s what you’ll need:

 

1. A smartphone
2. A magnifying glass lens about 2 3/8-inch diameter
3. Something to hold everything steady. (I chose eight pieces of manufactured wood product [MDF] in the following dimensions: (4) 5 1/2 by 5 1/2 inches, (2) 5 1/2 by 6 inches, (2) 6 by 6 inches.) I also used a few 5 1/2 by 1 1/2 inch pieces to set the phone on and a two-by-four for spacing.
4. 2-inch PVC pipe, 3 1/2 inches long
5. 2 hinges about 1/2 to 3/4 inches
6. Black spray paint and hot glue

 

You can make a projector out of materials as simple as shoe boxes, but I chose 1/4-inch-thick MDF because it’s easy to work with and consistently flat, along with a 2-inch PVC pipe piece. With this setup, the pipe can be moved closer or farther from the smartphone to focus at different distances.

 

You’ll also need some tools: a band saw, a drill or drill press, and a screwdriver. A hot glue gun will be helpful but not absolutely necessary.

Make the Housing

To determine the distance that your magnifying glass

will need to be from your phone, go into a dark room, turn your phone’s brightness up to the maximum available and hold the magnifying glass a few inches from the phone while pointing it at a wall. Experiment until you find the correct distance to hold the magnifying glass from the phone.

 

In my case, the distance from the phone to glass was around 6 inches, so I built a box to house my phone and hold the glass at roughly the correct distance. To adjust the focus, I glued the magnifying glass to a piece of PVC pipe that could slide in and out as needed.

 

To make this box (and internal holders), cut eight pieces of MDF in the following dimensions: Four of them should be 5 1/2 by 5 1/2 inches, two will be 5 1/2 by 6 inches, and another two at 6 by 6 inches. Save any scraps you generate in this process because you’ll also need a few pieces to set the phone on at around 5 1/2 inches long by around 1 1/2 inches. Cut a hole with a 2 1/2-inch hole saw through the center of a 5 1/2-by-6-inch piece and a 5 1/2-by-5 1/2-inch piece. These holes should be closely aligned, so try to drill the hole with the two pieces attached to ensure greater accuracy.

 

Assemble the box using wood glue, with the drilled 6-by-5 1/2-inch piece attached to a 5 1/2-by-5 1/2-inch piece on either side. Then, attach another 6-by-5 1/2-inch piece to form an open box. Set this assembly on a 6-by-6-inch piece of MDF on the bottom, and clamp or weight as necessary. Let it dry for a few hours.

Fit Parts Together

 

When you’re satisfied that your box is dry, glue the 5 1/2-by-5 1/2-inch piece with a 2 1/2-inch diameter hole in it 1 1/2 inches behind the front piece of the box (a piece of two-by-four can make a great spacer if available). Cut out the inside of the remaining 5 1/2-by-5 1/2-inch piece so that it looks like a sort of square “U,” with 1 1/2 inches on the bottom, and around 1 inch on the sides. The idea is to create a window for your phone’s display. Cut two of your scrap pieces of MDF to approximately 1 1/2 inches in width. Glue these pieces and then the U-shaped piece to the back of the box, creating space for a phone to slide in and out of. The dimensions may vary depending on the dimensions of your phone — and case, if you use one.

 

As an alternative, you could start off with a wooden box from a craft store, and add the necessary cuts and internal pieces. This would likely save time, but you’d need to find something quite close to the focal distance that you need.

Add the Lens

 

To install the lens, cut a piece of 2-inch PVC pipe to a 3 1/2-inch length, then notch out a 1 1/2-inch square on one side of the pipe (through both walls). Spray paint the pipe black, inside and out. After the paint dries, hot glue the lens to the uncut side of the PVC pipe and let it set. Slide it into the box to see how it fits — it will likely be loose.

 

To make sure the PVC pipe stays flat, place a small piece of wood or plastic between the PVC pipe and the hole it goes into to help fill any gap. I used a spare piece of plastic around 1/8 inch thick, but anything wide enough to fill the gap between the PVC pipe and the holes should work. It might not work perfectly the first time, but don’t despair. After gluing it on the first time, I had to remove the spacer and widen the hole slightly in that place with a file. When done, the PVC pipe should slide freely.

Paint and Add Lid

Once everything has dried and you’re satisfied that your projector will work as planned, paint the inside and outside of the box black to help absorb stray light. Additionally, paint the 6-x-6-inch piece that is left over on both sides. I used truck bed liner, mostly because I had it left over from another project, but it does provide a nice plastic feel to the finished product. Still, normal spray paint would be fine.

Once that’s dry, set the 6-by-6-inch piece on top of the box as a lid, with the best-painted side showing. Affix the hinges to the top of the box and the lid about 3/4 inch away from the edges. Place your hinges closest to where the lens will pop out so that the phone can be accessed easily.

Use Your Projector!

 

Once this is done, assemble the PVC lens holder with the cutouts facing to the side. Take this contraption to a dark room, turn your phone on to its brightest setting and insert it into the box facing the lens. Point it at the wall from a few feet away, and focus by adjusting the lens position. It may take some experimentation to get a decent image, but eventually you should be able to see a picture that is clear and bright.

 

One thing you will notice is that the projected image is upside-down. Be sure to change the settings on your smartphone to ensure your landscape orientation is “locked.” Depending on your device (iOS or Android), you may have to manually rotate any images that you wish to display by 180 degrees. If the display is not as sharp as you’d like, try making the room a bit darker.