Intro: Hidden Silhouette Lamp
This simple wooden block has a secret: with the click of a switch it becomes a table lamp! Using plywood, wood veneer, LEDs, and some simple electronic wiring, this project comes together in about a weekend to make a fun lamp for the home or office.
Step 1: Design
The idea for this project was pretty simple: I wanted to make a wood veneer box that would turn into a lamp at the push of a button. I've always loved wood veneer lamp shades, but I'm not into cavalier design and wanted something a bit more modern. The whole idea of light shining through wood is to turn the expectation on its head- wood is always opaque, this makes it translucent! The block design comes from this- why not really make the point by making the lamp appear to be a solid block of wood until it's turned on? The lightbulb shaped cutout adds another layer of playfulness I think.
I designed this piece in Fusion 360 (like pretty much everything else Iv'e made in the past year) because it's free indefinitely if you make less than $100K a year on the stuff you use it for, and it does everything I need quickly and reliably. If you want to learn to 3D model the kind of work I do, I think this is the best choice on the market. Click the links below to sign up:
The youtube video in this step is a quick tutorial on how to design something in Fusion using parameters. When you design with plywood, it can be very difficult to repeat a design if you're using a template or laser cutting. Plywood thicknesses vary from producer to producer, and even batch to batch, so making a master parameter that can be changed. When you design things this way, you can just change the "thickness" parameter from .23" to .24" when a different batch comes in, and all the geometry will update automatically. It takes a little more attention than just modeling something on the fly, but a stitch in time saves 9!
All four of the sides are identical with little tab / slot connections, and four ledges with pilot holes for the interior LED housing.
The .f3d file is the Fusion file, and the .dxf files are the 2D drawings you'll need for laser cutting or bandsaw / jigsaw cutting.
Step 2: Tools & Materials
I used 1/4" B-grade plywood for the carcass, 1/8" B-grade plywood for the LED carriage insert, and maple veneer for the surfaces. As I mentioned in the last step, plywood thicknesses vary greatly and these tolerances are tight. The cut files for this project are set to .23" thickness for the 1/4" nominal plywood, and the 1/8" plywood was actually 1/8" thick.
I joined the plywood joints with wood glue, and I affixed the veneer with 5-minute epoxy.
I cut the wood with a 120W laser cutter. You could do this project with a combination of a scroll saw (for the light bulb) and a band saw (for the straight cuts). If you're not sure how to go from complex 3D shapes to hand-cut parts, check out my Digital Fabrication by Hand instructable.
Step 3: Plywood Part Assembly
I won't bore you with the details of laser cutting.
For the plywood, I used Speed: 15, Power: 90, Frequency: 500
For the veneer, I used Speed: 70, Power: 90, Frequency: 500.
PRO TIP: Tape the veneer to a piece of scrap plywood before laser cutting to keep it from warping and distorting your geometry.
Wood & Veneer Assembly
- I joined the plywood parts with wood glue. There's only one way the parts will fit together, so it's easy to get this part on the first try. The 3D file serves as a good reference regardless.
- The AC adaptor housing has to be glued together with the adaptor inside since the wires go out through a hole.
- When the parts were cured, I mixed 5-minute epoxy, dabbed it onto both the plywood and veneer surfaces to make a tacky surface on both faces, then pressed them together with scrap plywood and pressure clamps.
Step 4: Electrical Assembly
- I used the double-sided tape that the LED panels came with an fixed them to the center of each panel on the insert.
- I used the wire harnesses the panels came with and soldered them in parallel to a piece of breadboard. In other words, all the black wires attach to the lead for the center pin of the socket, and all the red wires attach to the outer sleeve of the socket.
- I tested the setup with the AC adaptor- it worked!
- I used hot glue to fix the breadboard to the inside of the insert piece. I know it's not the most professional way to make this connection, but it works and it's easy.
- I didn't like the cheap, grey plastic wire that came with the AC adaptor, so I used some fabric wrapped lamp cord to replace it. I soldered the lamp cord to the short leads of the AC adaptor and used some heat shrink tubing to protect the wires.
- I used a bigger piece of heat shrink tubing to enclose the whole spliced piece coming out of the hole in the AC adaptor enclosure.
- I disassembled the connector from the end of the AC adaptor cord and soldered it to the end of the lamp cable. Remember, this is DC, so it's really important to keep track of + and -.
- To prepare for the switch in my circuit, I left two long leads on the - side of the socket to connect to the switch through the top of the box. I soldered them to the default-off leads on the switch.
- With the leads soldered, I screwed down the nut to keep the switch in place. This was tricky because the box is too small for my hands to fit in.
- With everything wired up, I inserted the LED box and screwed it into place with some small wood screws.
- The power cable connects to the bread board inside the box.
Step 5: Complete
This lamp works like a charm! Keeping the wall wart adaptor is the safest solution to prevent fires, and the wooden enclosure keeps the piece consistent. It could definitely be brighter, and I might go down the high wattage LED rabbit hole at some point and see if I can make a serious light source out of it.