Theater Cube





Introduction: Theater Cube

About: Awesome Gear I've designed myself.

This box is a movie projector which uses your phone as the image source. Simply put your phone in, adjust the counterbalanced lid, and turn out the lights. Don't forget the popcorn. It also doubles as a memory box when not in use. I made this box to display something not easily noticed. It's a culmination of the skills I've collected while being a part of the Instructables community. That's why it took four years before I made it. As we go though this build, I'll include pictures from my past projects that brought me to this one.


Four years ago my son and I came across a treasure in the Las Vegas desert. Well, at least it was a treasure to me. Someone had dumped an old rear projection TV. It was one of those big screens that took up half your living room in the 90's. By the time we found it the screen was shattered out and everything else was battered with rocks. My curiosity was caught by a three lenses embedded in body of unit. I listened to my inner robot and decided to make something of it. It was too big to carry on my handle bars so I took some wire from the TV and tied it off to the back of my bicycle. I drug it all the way home and carefully dismantled the last pieces of the TV. I took out the lenses with the hope of using them for a future project. This is that future project.

Don't forget to enter the Make A Box contest and the Hand Tools Only contest. Good Luck.

Step 1: Tools and Materials

When I saw the graphic for the Hand Tools Only contest I was determined to use every tool on it. The only tool I didn't use was a scroll saw. But I did manage to use a scroll saw blade while cutting aluminum bar. This build was a fun challenge. I have to admit, my table saw, lathe, and drill press were tempting me. But it was just like old times, before I started collecting tools to make my creations.

Anyhow, most of what you need for this box can be found at your home improvement store. It includes plywood, aluminum bar stock, and brass nails. Other items include leather cord, a mason jar lid, and a convex lens. You can find a lens online if you don't want to search the desert for one. I found a picture online so you could see what the lenses looked like when I found them.

Step 2: Inner Lens Carrier

As far as designing this box I did it from the inside out. First I had to figure out how to mount the lens while making it look decent. I tried a few different ideas (see the last step for my failures) before I settled on using a mason jar lid. The problem was, I needed to center the lens within the lid and figure out how to keep it in place.

I remembered how I used stretchy bracelet cord to keep an acrylic circle in a jewelry box i made. Instead of the stretchy cord I used leather for this lens. To keep it in place after that I used aluminum bar. First I shaped it into a circle by bending it around a bearing race. After trimming it down with a jig saw blade I popped in it. Next I used silicone sealant to keep the ring in place.

Step 3: Cutting the Cube

I used a circular saw guide to cut a plank off of my sheet of plywood. First I added an extra piece of wood to it so the saw would be more accurate as I pushed it along. I adjusted it to about 7" and started cutting. Gravity will want to pull the wood down so make sure you use a C clamp to keep the lead kerf splinter free.

Once I cut the plank, I continued with the the same guide distance and cut 4 squares. To make the lid and bottom I moved the guide out about 3/8 of an inch. This made the next two squares just a little bigger. I'll trim off the excess in another step.

Step 4: Mark, Drill, and Countersink

I used my square to mark the locations of the screws. This is important so they stay centered on the edge of the adjoining piece. I marked them with an automatic center punch. Before I added the screws, I counter sunk all the holes so the screws would sit flush.

Step 5: Gluing and Screwing the Box Together

I made sure to drill pilot holes to avoid splitting the plywood. After applying glue to the joints I waxed the screw threads before joining all the sides together. I wiped up any glue with a damp cloth. I did all these same steps when I made a blanket chest.

Step 6: Trimming the Lid and Bottom

I glued and clamped the top and bottom. Sometimes things don't always line up square. This is why I cut the lid and bottom over-sized. By using a flush trimming router bit I'm sure to cover all the edges.

Step 7: Cutting in the Lid

For some reason this reminded me of cutting a lid on a pumpkin. First I marked a line all around the box. Then I carefully eased my handsaw into one corner of the box. With each stroke I guided the blade so it would stay on the pencil line. Once I got to the other corner, I rotated the box and repeated the procedure. by cutting the box apart like this I ensured the lid lined up perfectly.

Step 8: Making Room for the Mirror

Since a mirror is going into the lid, I used a rabbit bit to cut a relief for it. A razor blade made quick work of squaring the rounded corners. From here I rubbed the lid on a sheet of sand paper to help even out the saw marks.

Step 9: Cutting and Shaping the Aluminum Accents

Back when I made a small samurai sword I used a chisel to cut the steel bar stock. This method worked just as well for aluminum. I only new that I could bend aluminum at 90 degrees because I did it when I made a camera trolley. After taking measurements, I used a vise and hammer to form the bends.

Step 10: More Drilling and Brushing

I pencil marked holes every inch followed by a center punch. When it came time to drill the holes I did good for a few but broke a drill bit. I knew it broke because I put too much pressure on the handle of my cordless drill. Keeping that in mind, I replaced the drill bit with the next size up and kept going. A few holes later I broke another one. All I had now was an even bigger drill bit. I thought about going to buy a new one but I decided to work with what I had. As each piece was drilled out, I filed off any burrs and used 120 grit sand paper to add a brushed finish.

Step 11: Adding Character

So breaking drill bits turned out to be a stroke of luck. I was worried that the small brass nails I was going to use would be too small for the holes I drilled. To shrink the diameter of the holes I used a ball punch and hammer. Every hole was struck which not only made them smaller but gave it a better "riveted" look. I used a ball punch to set rivets while I made the prototype for my doughnut safe.

The nails I used are the same ones from the Ladybug pendant I made. I kept cutting and filing every piece until I had enough to cover the box. With the help of my pliers and tack hammer, I hammered all the aluminum on.

Step 12: Counter Balancing the Lid and Adding Hardware

Here is where I added most of the hardware. The lid still needs the mirror so I couldn't counter balance the lid just yet. However, I thought this was the best step for the picture showing the springs. First I added springs to the hinges to help add tension. Next, I opened the lid to the angle I wanted and pulled on the main spring until it kept the lid in position. After marking the location I mounted it with a screw. Now my lid stays up when I open it.

Step 13: Cutting Out the Mirror

This part was nerve racking. I have never cut glass before. I knew all I had for material was the mirror I found in my neighbor's trash a week earlier. It's funny how if you read directions you have a better chance of success. I figured out that placing the glass on cardboard kept it from breaking as opposed to scoring it while on concrete. Having a rod to brake the glass over also made a huge difference. I cut the glass with the help of a square. I made sure to cover the back side with duct tape in case the glass was ever shattered.

Step 14: Mirror Installation

So now I had a jagged square of glass without a way to finish the edge. I remembered the bar pendant I made. I went back to the same file folders and cut the steel strips to cover the mirror's edge. Silicone sealant kept it all in place.

Step 15: Cutting Out the Lens Carrier

I used a hand saw to cut a square. I then used a block plane to shave it down to size. These minor adjustments are important because you want to lose as little light as possible to the seams.

Step 16: Fitting the Lens

This is an old wood working trick for cutting circles. I remembered it from when I made my Mom a hand mirror. I used this method to recess the mirror into the wood. To do it you simply mount a piece of wood to your router base and then use a nail as a pivot point. With a few turns I had a perfect circle for my mason jar lid.

Step 17: Securing the Lens and Adding Handles

I used the same strips of metal from the file folders to pressure fit the lens carrier into the hole I cut.

I bent the handles in my vise. I didn't want the handles going all the way through the wood so i made a drill stop with electrical tape. Before I pressed them in I flared the edges of the aluminum with a small hammer. This helped keep them in place very well.

Step 18: Lining the Inside With Sheet Metal

Adjusting the lens to the proper focal point is done with the help of magnets. I lined the sides with sheet metal for this purpose. The to help support the lens carrier I added six small magnet to the edges of the square and four large magnets to the sheet metal. To adjust the lens you simply push the carrier down until the the image is clearly projected.

Step 19: Creating the Speaker Gromet

Normally I would use my lathe for this. But why use a lathe when you have a cordless drill. To start I cut away the unnecessary material with a razor blade. I then placed the grommet on a bit and rotated it while sanding it with sand paper. Finally I glued it in.

Step 20: Clean Up

It is quite difficult to clean up after silicone sealant on a mirror. I ended up using fine steel wool followed by a paper towel and rubbing alcohol. You want a clean mirror for a clean projected image.

Step 21: Adding a Wax Finish

I used this same finish on a past jewelry box. To do it you melt a candle over the wood and used a heat gun and cloth to rub it in. You can also rub the candle on the wood before heating it up. It darkens the wood to natural rich color.

Step 22: How to Use It

Make sure your lens and mirror are clean. Turn your phone to the brightest setting and set in the bottom of the box. Place the carrier in and close the lid. The handles push against the mirror and lower the carrier to the proper focal point. Turn out the lights, open the box, and enjoy the show. The projection does look better in real life then through a picture.

Step 23: What Didn't Work.

I took 502 pictures during this instructable. A lot of those pictures never made it to any step. That's because there was a lot of trial and error. This includes how the lens would be mounted, trying to make my own hardware, and choosing the right hardware itself. I had a great time.

Thanks for reading.

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    21 Discussions

    Of all the cellphone projectors that I have seen (including shoebox projectors), not one has focused on sound by adding speakers to complete the movie experience.

    What size lens is it?

    Well, I found a tv. Not in the desert, but on the street. Got all three lenses out. Advice on how to remove them from the focusing housing? Also, did you use the top or bottom lens?


    Very nice Theater Cube. I like the ingenuity that you used to make the lens work. When I first started reading that you were using magnets inside the box I thought it would interfere or even damage your phone but then I saw in the picture that it was a small magnet and not next to the phone. I like the overall appearance of the box with the metal around it. It reminds me of old suite cases and trunks. Your photos and instructions were easy to follow. Great job and good luck in the contest.

    I am really impressed with this! Such creativity and thought has gone into this.....I can't wait to try this....I think the hardest part for me is to find the lens and mirror. You deserve a vote!

    Very impressive instructable! I've been "collecting" discarded projection televisions for some time. I have quite a few of these lenses and wondered what could be done with them.

    Did you notice the huge mirror on the back panel of the television? It's extremely valuable for projects of this sort, as it's a front surface mirror. Touch the surface as little as possible as skin oils can damage the material that provides the reflection.

    Front surface mirrors are useful in astronomy projects, but even in this project, you would have even better results in the image. In an ordinary mirror, some reflection is had from the glass of the mirror and of course, the primary reflection is to be had from the silvering on the back. You get a ghost image from the glass, but it is usually ignored or over-powered by the primary reflection.

    With a front surface mirror, all the reflectivity is from the front. Of course, the mirrors in a projection television are quite large and should be handled with care.

    4 replies

    That is great information. I never would have thought of that. Maybe next time I'll use a piece of polished stainless steel .

    Would a piece of Mylar possibly work better?
    I really don't know, just an idea.

    mylar is quite flexible. It would be nearly impossible, in my opinion, to get the mylar sufficiently flat to provide an undistorted image.

    Even highly polished steel is less precise than a front surface mirror. For "human consumption" an ordinary mirror would be okay, unless one can detect the ghost image of the reflection from the glass surface alongside the real reflection. If you can, I retract the "okay" part.

    The TV was found in the desert. It was dumped and people broke it with rocks.

    Great craftsmanship and Instructable.

    I'm more interested in your box making than the projector inside. I really like the way you hid the plywood edges and made it look more elegant with those straps.

    I like the explanation, and the using of each of the tools. Even if I don't build this box, the step-by-step is fascinating. Thanks, I enjoyed the read...

    The box is cool, and well made. But the pitcher quality seems horrible, not even watchable. Given that fact, I don't see the point. If it doesn't project properly, is it a "projector" ?

    1 reply

    It looks better in real life than it does in video. But I just learned here that the mirror distorts the image.

    A great 'ible: a BIG thanks for sharing it withh us.

    Typically when a mirror is used in a projector, a front surface mirror is used. This instructable uses a back-surface mirror, so the different colours of light will refract at different angles as they enter the glass, reflect off the rear reflective surface, and exit the glass. There will be some ghosting across the colour spectrum on the projected image as a result.

    I've seen quite a few phone projector projects on instructables but you've taken it to a whole new level with the elegant looking box. No one could imagine it's a projector if he hadn't seen it in use earlier.
    Beautiful project as always :)

    1 reply

    Wow! You did an amazing job documenting this project. I've considered doing something like this since I saw a Mr Jalopy article on a home build theater rig in Make magazine a few years back. Even if I don't compete this project, there is enough detail for me to apply your fabrication tips to other projects. Awesome work - thank you for sharing.