Dynamic LED Lighting Shadow Box and Frame for Art:

Lighting is an important aspect of visual art. And if the lighting can change with time it can become a significant dimension of the art. This project started with attending a light show and experiencing how the lighting could totally change the color of an object. We began to explore this in lighting fabric art. So far we have built dynamic lighting for 8 pieces including a painting and a photograph. The lighting effects have included: simulating dawn and sunset, underwater light through a rippling surface, lightning in clouds, and dramatically changing the perceived colors and mood of the art work.

This instructable builds the shadow box and frame that holds the LEDs and illuminates the art piece. You will also learn about many problems and improvements we discovered along the way.

We also wrote an associated instructable on building the lighting controller. The programming section of that instructable contains videos showing several dynamic LED lighting effects. Check it out at: https://www.instructables.com/id/Dynamic-LED-Ligh...

For now we will focus on the physical structure that holds the LEDs and reflects their light onto the artwork.

The concept is simple: LEDs around the shadow box reflect their light off a mirror surface on the back of the picture frame to illuminate the art work. However the artist must plan for the reflective picture frame to be from 1.5 to 2 inches wide. The artist needs to provide a wider-than-normal background around the focus of the piece.

We used an experimental lighted frame to determine the depth of the shadow box. If the art piece is larger the shadow box needs to be deeper to cast the light into the center. If the art piece has a lot of depth the shadow box also needs to be deeper. Our shadow boxes were between 2" and 4.5" deep. The art work in this project was between 12" and 30" in the longest dimension.

• Wood for shadow box sides: 3/4" x 5-1/2 (width 3/4" wider than depth of shadow box) we used poplar. Very important that wood is clean, straight, flat. We purchased very good wood from a molding mill at a very good price.
• Molding for the reflective frame: See picture above. Frame needs to be 2" to 3" wide. We bought ours from Anderson McQuaid in Cambridge, MA. http://www.andersonmcquaid.com
• Wood glue: We recommend Tightbond III with the green top.
• Contact cement: We recommend Barge all purpose cement.
• Wood joining biscuits: No. 0 Size.
• String of WS2812 LEDs https://www.adafruit.com/product/1461 We used 60 LEDs per meter, higher and lower density strips are available. Our pieces required reduced ambient light. If your piece will be viewed at normal ambient light levels I would suggest going with the 144 LEDs per meter.
• 1" wide adhesive backed Velcro
• Adhesive backed reflective mylar. https://www.michaels.com/cricut-metallic-adhesive...
• Machine screws #6-32 x 2.5" flat head phillips
• Brass wood screws #2 x 3/8" flat head phillips
• Brass wood inserts #6-32

You don't need to own all these tools. I used my son's workshop that has most of these tools. You can probably come up with an alternative approach if you don't have a particular tool.

• Miter saw
• Table saw
• Router
• Biscuit cutter
• Drill press
• Dremel tool
• Pull saw: I suggest: IRWIN Marples Dovetail 7.25-in Pull Saw available at Lowes for about $14
• Sanding stick: strip of wood about 12" x 1.5" wide x about 0.5" thick with 100 grit sand paper on one side and 220 on the other. I use contact cement to glue the sand paper on.
• Medium and small Quick Clamps: Lots of them. No one has enough clamps!
• Deep throat C-clamps
• Framing square
• Tri-square
• A flat surface you can clamp to: I got by with a 30" x 6" very flat board, but a large surface (like the bed of a table saw) would be much better.
• Right angle brackets: My brother made me some but I think you could do the same with blocks of wood carefully cut to a right angle.
• Razor knife and numerous other hand tools, see all the steps for details.

• Check your measurement before you cut (check twice!)
• Try the fit before you glue
• Test as many steps as you can before committing the good materials
• If you can mock-up a test frame to explore the shadow box depth, light intensity, and reflector width that works best for your art piece.
• To play it safe go with a little extra shadow box depth and more LEDs than you think are necessary. If you over-build later on you can turn down the light intensity with the controller.
• Plan where things go: We embedded the controller in the top center of the frame, we started our LED strip in the top left corner and went around the frame clockwise from the perspective of someone viewing the art.
• There needs to be a wiring channel cut into the top of the shadow box from the controller to the top left corner.

The picture above shows the pieces for two shadow boxes cut out. One is about 4" deep and the other about 2" deep.

• Cut width of shadow box sides to equal shadow box depth plus 5/8" for the "rabbet" (The "rabbet" is art frame speak for the notch cut in the back for mounting the art)
• I cut the rabbet with the table saw. Use a scrap piece of wood to check the cut depth and width.
• Bevel the top inside edge 22 degrees creating a 1/2" wide surface for the LEDs. Again it is best to test your saw setting with a scrap.
• Miter the ends to 45 degrees. Making the length of each side the size of the art piece plus 7/8" which will allow a small gap around the art piece when it is set in the rabbit.
• Use the table saw to cut a wire channel in the top piece, from about the center to the upper left corner.
• Using the miter saw I cut the picture frame so the outside dimensions are 1/8" to 1/4" larger than the shadow box.

NOTE: For best results with a miter saw: clamp or hold the wood firmly to prevent it from moving. Make the cut slowly as the blade tends to bend a bit when cutting on an angle.

• Mark the center line of the frame and lay-out the size of the controller pocket. Ours is 2.5" x 1.5" with a 1/4" recessed lip for support & attachment of the controller "door".
• It is hard to get a straight cut where you want it with a router. I made a hard wood guide pictured above. The 1/4" diameter router bit follows the inside of the guide giving me an accurate hole with straight sides. Our pocket is 0.62" deep leaving the wood at the bottom of the pocket about 1/8" thick.
• The "door" on which the controller is mounted is two layers of veneer which winds up about 0.05" thick.
• I cut the 1/4" wide recess around the pocket about 0.04" deep. I clamped a straight board over the work piece as a guide for the router. A test cut in a scrap piece allowed me to measure the offset between the router cut and the guide, which for me came out to be 2.156" wide.
• The router leaves the corners of the recess rounded, cut these out to square using a razor knife and chisel.
• For construction and mounting of the controller see the related instructable: https://www.instructables.com/id/Dynamic-LED-Light...
• I attached the door with two #2 x 3/8" Flat head brass screws.

• The corner joint needs more strength than just glue can provide. The easiest option is to use finish nails. I opted for a biscuit joint where a lemon shaped piece of wood is embedded in the joint. Fortunately my son has a biscuit cutter which I used.
• To get good results, the biscuit cutter is attached to a board and clamped down. The angle guide has a board attached to it to securely hold the work piece so the pocket will be cut at correct angle to the miter surface. The biscuit pockets must be exactly the same distance from the edge on both pieces for the corner to match when glued. Clamping everything helps and you need to hold the handle of the biscuit cutter down consistently when pushing it forward to make the cut.
• If the slots don't match up perfectly you can make them a little wider using a sanding disk as pictured above. This will give you some play in the joint so you can clamp it in alignment when gluing.
• To set the depth of cut the biscuit cutter has a knob with fixed depth pockets for each size of biscuit. I found these settings to be a little deeper than necessary which results in the pocket cut being wider. This was a problem on some of the frame moulding. So I made a clip-on ring (see white object in the third picture above) to reduce the pocket depth by 0.04". You can accomplish the same result with a piece of appropriate sized wire bent around the depth adjustment knob. Again test and adjust to get the optimal depth cut.
• Biscuit joints on mitered corners is tricky and a lot of work. Feel free to try finish nails on a test corner to see if that works for you.

• You need to check the joint and make any adjustments before you glue.
• This is very similar to what you will do when gluing the joint.
• You need a very flat surface that you can clamp to. I have a very flat 6" wide board and this worked ok but bigger would be better. This is necessary for the two halves of the frame to match up later.
• The shadow box sides or picture frame sides need to be held flat and at right angle. Use a framing square to check the angle.
• If the joint has a gap, I used a pull saw to recut the joint by gently letting the saw follow the existing cut. I did this with the joint still clamped. Of course you do this without the biscuit in the joint. This will take out a very small amount of material from the tight spots allowing the joint to come together better.

• This process is the same for both the shadow box and the picture frame.
• Dry fit each joint before gluing.
• Inspect and sand the biscuits a little. They sometimes have splinters sticking up that interfere with joint assembly.
• Use a high quality wood glue like Titebond III which gives you a little more assembly time to get the joint aligned and clamped in place.
• Get the joint as tight as you can, as square as possible, and the sides of the frame flat.
• Measure the length between the tips of the unglued ends. This is the diagonal distance across the frame. We will need to make the other side have the same diagonal distance.
• Next glue the diagonally opposite corner. Don't forget to insert the biscuits.
• Now we have two halves of the frame and the final step is to glue the two remaining corners at the same time. This takes quite a few clamps as seen in the picture above but the final result will be beautiful.

• I wanted to be able to disassemble the frame from the shadow box in case the lighting needed maintenance. So I choose to attach them with #6-32 x 2.5" machine screws. This required drilling a hole 4.5" deep through the 3/4" thick shadow box sides.
• This instructable has some "over kill" feel free to attach the frame to the shadow box in some other way. Putting long holes through narrow boards is tricky. And, you may want some of these tricks for other projects so read on.
• Do all of these steps with a test piece until the drill hole comes out close enough consistently on the other side of the board.
• This needs to be done in an drill press. Clamping the board consistently is key to getting the hole to go straight through.
• A vise, clamped to the drill press bed, aligns the board in one direction. A level as shown above is used to align the other direction.
• The rabbet presents another challenge with the side of the rabbet in the middle of the board just where we want the hole. Clamping a scrap piece of wood in the rabbet creates a "solid" piece of wood in the center so the drill will tend to go straight.
• I used a short center drill to make a starting hole.
• Next I used a 6" long 1/8" drill to drill all the way through. For the deeper shadow boxes I am drilling a 4.5" deep hole with a drill press that has only 3" stroke. This required drilling part way and then re-chucking the drill bit further out.
• The head of the bolt needs a clearance hole so it will be below the level of the rabbet. And the bolt length needs to extend about 3/8" beyond the shadow box. I drill the clearance hole 9/32" diameter to the desired depth before moving the part. See the third picture above.
• I put four attachment holes in most of the shadow boxes.

Threaded brass inserts for wood are a great fastener than permits repeated disassembly. The following is the best way I have found to install them.

• Clamp the shadow box and frame together carefully getting them aligned exactly.
• Using a hand drill with the long 1/8" bit to drill pilot holes in the frame. Mark the drill bit with tape so you will know when the hole in the frame is the depth of the insert. Obviously important to not drill all the way through the frame.
• Take the shadow box away and drill out the holes to the correct size for the inserts. In my case that was 5/32" dia. Again mark the bit for depth. Take extra care to hold the drill back because with a pilot hole the drill bit will pull itself into the wood more than usual and you could loose control.
• Now here is a really cool discovery. The inserts come with a screwdriver slot in the top for installing them. I have had bad experiences in the past with the slot stripping or the insert breaking. I now use a short cap screw that fits the insert along with a small square of aluminum with a hole in the center. A hex wrench is used to screw the insert into the frame. I hold the aluminum square washer to keep the insert from backing out and remove the cap screw.
• The 1/8" hole through the shadow box is a bit tight on the #6 machine screws so I drill it out to 9/64" diameter.

• Determine the width of the reflector: Assemble the shadow box to the frame and make a pencil mark on the picture frame around the inside edge of the shadow box. Measure the distance from the pencil mark to the inside opening of the frame.
• Take the picture frame off of the shadow box.
• Cut enough strips of adhesive backed reflective mylar to go around the picture frame.
• To prevent the reflector from showing stick it down just a little back from the inside edge of the picture frame.

More on the electrical side of this project in the companion instructable: https://www.instructables.com/id/Dynamic-LED-Lighting-Controller-for-Art

• Cut strips of LEDs for each side of the shadow box. Allow some space in the corners so the LED strips should be between 1.5" and 1/2" shorter than the inside length of the shadow box side.
• The LED strips have a communication direction. The arrows on the strip should point away from the end where the controller wire is attached.
• I found it easiest to clamp the strip to a board while soldering. I also cut a notch in the end of a shish kabob skewer to hold wires in place while soldering. I used 26 gauge stranded wire.
• To go around the corners I cut pieces of wire 1.75" long and formed them into a loop connecting one segment to the next. Pay attention to the direction of the arrows on each segment.
• The last segment gets a 200 ohm resistor between the communications line and the negative power line ("ground"). I found it helpful to cover the legs of the resister with silicone insulation stripped from some wire.
• To help with power distribution I connect the Positive and Negative power lines from the end of the last segment to the start of the first segment (where the controller is attached).
• This is the right time to test the LEDs. Once they are glued to the shadow box they are hard to repair. Hook up the controller with some test program and see that all the LEDs work.

• The adhesive backing on LED strips does not hold reliably to bare wood. Coat the beveled edge with contact cement. After it dries for about 15 minutes apply the LED strip. I suggest doing one edge at a time.
• Then stuff the wire to the controller in the "wiring channel" saw cut and hold it in place with hot glue.
• The second picture should have a reflector on the picture frame if the steps in this instructable were followed.
• Last I push the little loops of wire into each corner.

• The shadow box needs to be lined. We used either cloth of a color that contributes to the art piece or black mat board. For adhesive we thinned Titebond wood glue with water and painted it onto the shadow box one side at a time. We then pressed the liner to the glue and held it in place for at least 30 minutes.
• The fabric art we glued to a 1/4" thick piece of wood paneling using a spray adhesive. Different kinds of art work will require different mounting methods.
• For a finished appearance we placed a piece of mat board behind the paneling.
• Using a pencil I marked places around the shadow box where I want attachments.
• Next cut a 1" long grove 1/8" deep using a dremel tool with a 3/8" diameter cutter. See photo above.
• From 24 gauge sheet metal I cut 3/4" wide strips 2" long and using a coin as a templet rounded the ends.
• These tabs hold the art in place using 1" wide adhesive backed Velcro with the loops on the sheet metal and the hooks on the mat board.
• There are many methods for holding the art work in the shadow box. I like this method because it allows easy access and reassembly.

This is one of two instructables on this project. If you haven't already, check out the companion instructable at: https://www.instructables.com/id/Dynamic-LED-Lighting-Controller-for-Art