The majority of the lamp is made of 1/4" and 1/2" Baltic Birch plywood. I love using this stuff to make things - a quick skim of my other instructables will confirm that! It's strong and stable and easy to cut - and it's made of a renewable resource! What's not to love? Wood dowels serve as the joints. The springs and socket were stolen from two old lamps; one skillfully located at a thrift store by my wife, and the other was just taking up space in my house (and also "donated" by my wife). The LED lamp draws just 3W to produce 180 lumens, enough to illuminate a small work area. It was bought at DealExtreme, but nearly any LED bulb with an integrated reflector would work just as well.
Total cost for this project was $25-$30.
Now, you may be thinking, "Hey - this looks ideal for a laser cutter or CNC machine!" Well, you're right. At the moment my designs need a bit of work so they're actually compatible with an automated system - anyone willing to do the conversion? There's a 3-month pro membership for the first person who does!
So, have you got access to a scroll saw and drill press? That's pretty much all you need to make this awesome lamp!
UPDATE: KChappers generously converted my designs to .dwg, .dxf and .cdr formats for your CNC, laser cutter and 3D rendering pleasure. Thanks so much!!
Step 1: The Design
When designing the lamp, I took measurements from an existing lamp I use at my workbench. I noticed that all of the "arms" are made of equal-length sections, connected by triangular "joints." This made the design relatively easy - just two parallelograms with a "shoulder" at the base, an "elbow" in between, and a "wrist" where the arm connects to the reflector. Indeed, you will notice that is exactly how I labeled the parts.
In addition, there's the base and various spacers.
Everything is designed to be cut out of either 1/4" or 1/2" plywood. Since there are many identical parts, you can stack the 1/4" wood and cut it in pairs. Not only is this faster, it also ensures that the joints are precisely aligned (this is important for the arms and joints especially).
The patterns are intended to be printed out on 11x17" paper - if you don't have this capability at home, any business supply store or print shop will be able to print the patterns for you. I printed mine at work.
Also note that you may need to modify the design of the reflector section to suit the lightbulb socket you've got - the diameter may need to be increased or decreased, for example.
Included below are the preliminary patterns - I plan to clean them up soon, to make the whole thing easier to build!
A HUGE thanks to instructables user KChappers, who cleaned up, organized and converted my designs into .dwg .dxf and .cdr for me!
Step 2: Materials and Tools
1 or more discarded lamp fixtures, from which you can extract:
1 standard light bulb socket, with built-in switch
1 two-conductor cord with attached plug (likely attached to the socket)
4 springs (the ones I used were 4.25" long, unstretched)
other assorted hardware
One 1x2 foot piece of 1/2" Baltic Birch plywood
One 1x2 foot piece of 1/4" Baltic Birch plywood
1/2" wood dowel (it usually comes in four foot lengths, that's more than enough)
1/4" wood dowel (it usually comes in four foot lengths)
One 2" long, 1/4" diameter stainless steel screw
Two 1/4" stainless steel washers
One 1/4" stainless steel butterfly nut
Spray glue (for affixing patterns)
A scroll saw (I use a Dewalt DW788)
A drill press
1/8", 3/6", 1/4" and 1/2" brad point drill bits
3/4" and 1" Forstner drill bits
A vertical belt sander (optional)
A few clamps
As I mentioned before, if you've got access to a CNC machine or a laser cutter, you should be able to cut out the parts with one. The only catch is that you'll need to modify my design files so that you have usable tool paths.
Step 3: Print and Attach the Patterns
I had a lot of straps lying around, so I took the opportunity to use them up where possible.
If you plan the layout of the patterns just right, you can lay down half of the required pieces, then stack one piece of wood on top of the other. Tape the layers together so they won't slide around.
Roughly cut out all the pieces on the scroll saw, and re-tape where necessary to keep the halves firmly attached together.
Step 4: Drill the Holes
It's easiest to drill all of the same-size holes at once. I started with the 1/2" holes, since they are the most numerous. Then I did the other size holes.
Some of the pieces also have internal cuts. They'll need a pilot hole drilled, through which the scroll saw blade can be fed. I used the 1/4" drill bit for this.
When drilling, make sure you place a piece of scrap wood below the piece being cut. This will help prevent "tearout," which could ruin the look of the lamp.
Keep the matching "pairs" together until cutting is complete.
Step 5: Cut out the Pieces
One trick you may use for cutting out the stacked pieces is to stick a short piece of dowel in two of the holes. This will prevent the pieces from shifting far better than the tape is able to.
Cut each piece carefully, to the line. In most cases you don't have to be super-precise, though you should be careful when cutting the joints that slot together. These include the reflector, the the joint between the "shoulders" and base, and between the "feet" and base. Take your time to cut these precisely, so that the pieces fit together later with a minimum of wobble.
To do the inside cuts, disconnect the scroll saw blade on one end and feed it through the pilot hole. Reconnect the blade, re-tension it, then cut out. Disconnect the blade again to remove the workpiece.
The pieces may now be sanded to remove any rough edges and faces. You can use a belt sander for the edges if you've got one. Sand to the line using the belt sander. One the edges are are sanded, remove the paper patterns. If the paper won't come off easily, heat it up a bit with a heat gun. The adhesive will release easily, but you'll need to sand the residue smooth. Lightly sand the faces of all the pieces, and sand the corners to remove any burrs.
One final step is to drill holes through the 1/2" spacer pieces. The cord will eventually pass through these holes, which are drilled perpendicular to the main 1/2" hole in the center. Using one of the scraps to support the spacer, and a clamp to hold it perpendicular, drill one or more holes large enough to accept the cord. This is a tricky operation, and a nice brad point drill bit really does wonders here.
Step 6: Cut the Dowels
From 1/2" round dowel, cut the following:
6 x 1.5" long
2 x 2" long
1 x 1" long
3 x 0.5" long
From 1/4" round dowel, cut the following:
1 x 1.5"
1 x 2"
2 x 1.75"
Sand the ends of each dowel to remove any burrs and roughness. Don't sand the sides at all, or the dowels will fit too loose! Depending on the thickness of the Baltic Birch plywood, these dowels may be up to 1/16" too long - simply sand or trim flush as necessary during the Assembly stage.
Now, for a bit of a tricky step. Drill a 1/2" hole into a piece of scrap wood. Insert each of the 0.5" long, 1/2" diameter pieces in the hole, and drill a 1/4" hole straight through the center. The piece of scrap helps hold the short dowel in place, and parallel to the drill bit. Do the same for the 1" long 1/2" dowel.
Two of the 1/4" dowels will need a little notch cut in the ends to prevent the springs from slipping off. With the scroll saw or a small hand saw, cut notches on either end of the pictured dowels, about 1/4" from the end.
Step 7: Assembly
Assemble the base first, it's the easiest. Slot a foot onto each space. Some may fit better than others in certain spaces, so fit as many as you can without having to bust out the sandpaper. In some cases though, you may have to sand or cut a little bit of wood to make something fit. If you're planning to clamp the base to a table, install the feet "upside down," so the base sits flush on a surface. Once the base is finished, set it aside.
Do the "reflector" next. Slot in the three fingers. Hopefully they'll stay in by friction alone, otherwise you'll have to carefully hold them in place until the light bulb socket is slid in the middle. With the light fixture in place, the whole reflector should hold together. Set it aside as well.
Now it's time for the arm. Lay out the "joints" first, then slide in the 1/2" dowels. The arms and spacers will slide onto these. The assembly should go roughly like this:
- The curved 1/2" arm sections each have a 1/4" spacer on either side. 4 per arm section. These go on the outside of the arm.
- The straight 1/4" arm sections that make up the "forearm" have a 1/2" spacer between them. This pair goes on the inside of the "elbow" and "wrist" joints.
- The straight 1/4" arm sections that make up the "upper arm" go on the outside of the "elbow" and "shoulder" joints.
- A single 1/4" dowel spans the distance between the third position on the shoulder. The springs for the upper arm attach to this dowel.
- The 2" long 1/4" dowel is inserted through two of the 0.5" long dowel pieces, which in turn connect to one of the 1/2" holes on the straight sections of the upper arm. The other end of the "upper arm" springs attach here. The exact distance depend on the length of the springs.
- One of the 1.5" long 1/4" dowels is inserted through the 1" long dowel with a hole drilled through. The other is inserted through a 0.5" long dowel with a hole. These are positioned on the "forearm" at such a distance that the springs are not stretched when the arm is "raised" That is, the springs should support the weight of the arm.
The reflector assembly is attached at the "wrist" using a 2" long 1/4" diameter screw, held tight with a butterfly nut. Two washers prevent the screw and nut from cracking the wood. Place a 1/4" spacer on either side (2 total), and tighten the nut to hold the reflector at the desired angle.
Finally, slot the entire arm into the base. If the spring tensions are set properly, the arm should stay where you move it. At this point, be mindful that none of the joints pop out. Remember, they're not glued yet!
Step 8: Build a Counterweight
Well, if you're planning to clamp the lamp to a table, there is nothing to be done. Skip this step.
But, if you'd like it to be freestanding, you'll need to add a counterweight to the base. Most desk lamps will have this of course so I shouldn't feel so bad about having to include this step. I really should have integrated the weights into the design a bit better, but oh well.
Included in the designs is a small box that can be assembled, filled with something heavy, and attached under the base to keep it weighed down. The box is made of four layers, two of 1/2" wood and two of 1/4". When stacked together, the box is a bit shorter than the "toes" on the base, and so it slips discreetly underneath. Cut out the pieces by stacking, as with the other pieces, then glue together the bottom and sides. Clamp until dry. There's no need to sand smooth just yet...
Fill the box with something heavy. I bought a bag of fine lead shot ages ago, that I use exclusively for filling counterweights like this. A far more noble cause than killing small animals, IMO. When filled the box should weigh nearly two pounds. Glue on the lid once the box is filled.
Once the glue is dry, sand the sides as a single piece to get a nice smooth finish. The counterweight is now ready to be glued to the base of the lamp.
Step 9: Gluing
Glue the reflector "fingers" by applying glue to all of the mating surfaces. Wipe off any excess glue. The shape of this piece makes it hard to clamp. But fear not! Grab some twist-ties (or solid core wire, in a pinch) and use one or two per finger to hold the finger tightly to the ring. The light fixture will not be glued in until the wire has been run.
Next, glue in the "toes" to the base. This is pretty straightforward, remove one toe at a time, apply glue to mating surfaces, and slide together again. If the toes fit loosely, make sure they are all coplanar and the base sits level. Prop or reorient the base as it dries if necessary. Make sure to wipe up any excess glue before it dries.
When the "toes" are dry, glue the "counterweight" to the bottom of the base. Note that this isn't necessary if the base will be clamped to the table.
And now, for the arm itself. The general rule to follow is to only glue the 1/2" dowel to the outer-most arm piece. Remember, these joints must swivel! Gluing the outermost pieces only ensures that the arm won't fall apart. Set the arm on its side and remove arm sections until the tops of the dowels are exposed. Apply glue to the inside edges of the arm or joint pieces, following the rule above, the slide them on. Doing it this way will ensure that any glue squeeze-out is pushed out where it can be wiped up, rather than into the joint.
Flip the arm over and do the same thing. Check each joint to make sure the pieces are pressed together.
Now glue the arm onto the base. Again, apply glue to the mating surfaces, and slide together.
The dowels are last. Take the dowels from the upper arms, and glue the 1/4" pieces in the exact centers of the 1/2" pieces. You'll then have two dowels, one with a 1/2" long section glued to the middle, and one with a 1" section glued to the middle. The first of these is glued in place to the 1/2" thick arm, closest to the elbow. The second piece is centered and glued to the parallel straight arms, closest to the "wrist." Make sure the notches cut into these dowels face away from each other, so they are able to hold the springs.
Last are the dowels that hold the springs for the "upper arm," between the shoulder and elbow. On one half, glue in place a 1/2" long drilled out dowel. The exact position of the piece glued to the parallel arms will depend on the length of the springs. Now, apply glue to the dowels themselves, slide them halfway through the holes, and slip on the springs. Push the dowel in the rest of the way to lock the springs in place. This part is rather fiddly, and a pair of needle nose pliers might be helpful.
Once all of the glued joints are dry, sand them to remove any glue residue that might remain. If any of the dowels stick out a bit, you may sand them down or cut them flush with a fine saw, or leave them alone. But, if protruding dowels prevent the arm from moving, you'll need to trim them flush.
Step 10: Electrical
Starting at the base, feed the wire from the back, towards the spacer at the front of the "shoulder." Slide the wire through the hole, and pull through enough wire to reach all the way to the reflector.
Feed the wire behind the first pair of springs, towards the "elbow." Feed the wire through the spacer here, being careful not to twist the wire. A twist won't affect the performance of the lamp, but it will look unprofessional. Can't have that, right?
Continue feeding the wire towards the "wrist," over the dowel that connects the two parallel arms of the "forearm." Poke the wire through the spacer at the wrist, and draw the wire tight.
Disassemble the bulb socket, to reveal the two screw terminals. Feed the wire through the end of the socket housing, and pull through enough wire that it's easy to work with. Split the two wires apart for about 2", then strip about half an inch from the end of each. Twist the strands of wire so they don't fray.
Secure one wire onto each screw terminal; it doesn't really matter which goes where. Double check for any loose strands that might short out and fix them. Now, reassemble the socket assembly and screw in a light bulb. Plug in the other end of the cord, and turn it on. It should light up!
Unscrew the bulb again, and slide the socket into the hole at the center of the reflector. When you're satisfied with the fit, apply a dab of epoxy around the perimeter of the socket where it contacts the wood of the reflector. Before the epoxy sets, make sure the switch is centered between two "fingers" on the reflector.
Once the epoxy is cured, attach the reflector to the arm using the 1/4" bolt. A washer should go on either side of the wrist joint. Place a 1/4" spacer on either side of the reflector. Tighten the butterfly nut until the reflector stays where you placed it. Too tight, and the wood could be damaged.
Screw the light bulb back in.
Finally, pull back any slack in the cord, to neaten the appearance of the lamp.
And that's it! The Woodpunk LED Desk Lamp is ready for action!
Step 11: Additional Modifications
I used an LED light bulb for my lamp because it looks awesome. Any LED "spotlight" you find should work fine here, because they are already focused and don't need a real reflector. However, if you're using an LED or fluorescent bulb that sends light in all directions, you're going to have to rig up a proper reflector or you'll be effectively staring into a bare bulb! One thing you could do is use the reflector from the scavenged desk lamp. It should attach to the "wrist" with a minimum of effort with the right set of wood spacers - but it won't look as cool.
Also, I would not recommend using an incandescent bulb with this lamp. They dump out a ton of heat, and I have no idea what effect that will have on the wood immediately next to the bulb. I really don't want to hear "I burnt down my house!" from any of you, ok?
You may also be tempted to extend the length of the arms. Feel free to do so, but be aware that the base will then need to be made heavier, or will need to be clamped to the desk to prevent the whole thing from tipping over.
Lastly, you may want to design an entirely different light for this lamp. You could use strips of LEDs, or LED ring lights, or anything else your imagination can conjure. Have fun with it and make it your own!
EDIT: Instructables user welderdoc sent me these epic photos of his version of the Woodpunk Lamp. It is made of 1/4" and 1/2" black acrylic. Fantastic work!