The Iris Lamp is a disc shaped wall lamp with a mechanical iris built in. Turn the disc and LED lights click on, shining through the moving iris and glowing through wood veneer.

This lamp is based on the Eclipse Lamp that I posted previously. I'm fascinated by mechanical movement in design that's typically static; this project was a fun way to explore this concept further.

Step 1: Tools & Materials

I made most of this piece on a 120 W laser cutter. If you don't have access to one, this piece would be fairly easy to make using a hand drill and jigsaw. I've provided templates here that can be spray-glued to plywood and followed with the tools. Check out my Digital Fabrication by Hand instructable for an extensive description of this process.

PLYWOOD

1/4" maple ply (actual thickness .23"). Most wooden components.
1/8" maple ply. Backer plate with keyholes for wall hanging.
Veneer. Maple surface applied to the front of the lamp.

HARDWARE

6-32 button head socket cap screws. 3/8", 1/2", 7/8"
#6 washers

ELECTRONICS

Step 2: Design

I looked at several different ways to make an iris, but I settled on the method carlbass uses in his Mechanical Iris instructable. I went with this one because it's simple (it works with 2D parts all cut from the same material), and I like the spiral shape it makes as it opens.

I designed it in Fusion 360(because it's awesome and it's free indefinitely unless you make more than $100K per year on stuff you make with it). The Youtube video here shows a preview of the joint assembly, which was a crucial part of for making the design work. It's possible to figure out this kind of mechanical assembly by simply drawing it in 2D, but it's SO much easier when you can make joints for the different parts and actually see what's going to happen mechanically when you make the thing.

Fusion 360 is free for students and hobbyists, and there's a ton of educational support on it. 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:

Student/Educator

Hobbyist/Startup

Measure twice, cut once, the saying goes... If you use good 3D software, you can avoid wasting invaluable time and materials down the road.

The .f3d file is the 3D file I used to design the piece, it may be useful if you want to make changes to the design for your own purposes (but remember, this is a non-commercial share-alike licensed design, so you can't sell it!). The PDF files are for laser cutting or any other type of CNC cutting. The "Manual" PDF file is laid out for easy jigsaw / drill cutting. The DWG file contains all of the 2D profiles that make up the piece.

Step 3: Hardware Assembly

VENEER: With the parts laser cut, I first adhered the veneer to the outer face disc. I did this using 3M 77 spray glue, taking some pointers from Jim Davidson. The right way to use spray adhesive is to spray an even coating on both surfaces to be joined, let them dry for about 5 minutes, then stick them together using a roller. Once it’s rolled, it’s stuck- there’s no turning back!
LINKAGE ASSEMBLY: With the outer disc finished, I assembled the parts to make sure the linkages worked. The parts are designed to have one hole that allows the screw to self-thread for a secure fit, and the hole on the adjoining part (the one on top of a given assembly) allows the same screw to move freely. It might not have been necessary, but I added a washer between the upper parts and their screw heads to ensure that the motion wouldn’t unscrew the screws.
ALIGNMENT FEATURES: The first version of this design didn’t have any features to keep the inner and outer rings aligned, so the iris moved around freely- definitely not the desired result. I went back into the model and added tabs on the fixed, inner circle and slots on the outer circle ring. The tabs use a single 3/8” screw as a post that bears on the inner surfaces of the slots to keep everything aligned.
GLUED PARTS: Seeing that the movement of the iris worked, I glued the slotted ring to the outer circle, using joining dowels and wood glue. I opted for this method of assembly because I didn’t want any exposed screws catching on the fixed ring with the tabs, and I wanted a consistent joint between the two pieces with no gaps. After gluing and clamping, I used a Japanese flush saw to trim off the dowels.
TEST MECHANICS: With the ring fixed to the front disc, I then did a test run of the motion of the piece. I added 3/8” screws to each of the tabs on the inner, fixed ring, then screwed the entire back panel together with the 7/8” screws. The piece didn’t move smoothly enough, so I added washers between the ring that’s linked to the iris arms and the spacer rings. This did the trick, and the motion worked smoothly. for this test, I also had the roller switch attached to make sure it engaged as the outer ring moved- I designed a little ramp on the inside of the fixed disc that would compress the roller switch as the ring moved.

Step 4: Electronics Assembly

LED: With the mechanical assembly working properly, I added the LED strip to the inner ring. The strip Can be cut in increments of about 1.5”, so I was able to use a 12 segment strip leaving a ~1.5” gap for the socket and wiring. I used 5-minute epoxy to fix the LED strip to the inner ring.
SOCKET: Two of the spacer rings have a protruding gap in them which give the socket material for its flange and nut assembly to bear on. This feature provides a makeshift hole in the edge of the plywood pieces, allowing the power cord to connect without interfering with the placement of the piece on a wall.
WIRING:
1. I soldered a red (standard for [+]) wire to the [+] lead on the socket, and soldered its other end to the default-off lead on the roller switch. This kind of switch has one lead for default-off and one for default-on, so I made sure to test the switch with a multi-meter before soldering.
2. I soldered another red wire (remember, this is still the [+] pole on the circuit) to the [+] contact on the end of the LED strip.
3. I then soldered a black wire to the [-] contact on the end of the LED strip, and soldered its other end to the [-] lead on the socket. A quick test of the switch with the power connected, and it worked like a charm!
SECURING WIRING: Since the roller switch is attached to the outer disc (!DESIGN FLAW!), the wiring gets moved around when in use. To keep the wires from shorting out, I hot-glued the ends of every contact extensively to isolate the contacts.

Step 5: Finished Product, Lessons Learned

It seems to be working pretty well, and the effect is fun. In hindsight I would have designed it so that the roller switch would be fixed to the stationary part of the lamp, and the ramp that engages the switch would be fixed to the moving part. This way, I would avoid any risk of shorting out the wires.