Introduction: Low-Poly Geometric Lamp
I moved across the country this summer for an internship working in a field I'm really passionate about. While I've had an awesome time and have really enjoyed exploring a new city, I had a nagging feeling that something was missing. It took me a while, but I finally figured it out; I missed making things! These past few years I've been too busy with university and internships to work on many projects. I decided that this had to change. Since I was 4500 km from my tools, I had the perfect excuse to try something new!
I haven't spent a lot of time working with CAD software and 3D printing. Pretty much everything I've done has been a 2D-sketch extruded upwards; functional, but not the most ambitious or eye-catching. Recently, I've also been interested in playing with light as a medium (check out the awesome work of James Turrell). Throwing in my obsession with geometric shapes, this project started to take shape. I love the contrast of the warm and soft diffusion through the body of the lamp with the cooler, brighter light coming from the openings.
Step 1: What You Need
- 1/8" diameter, 1/16" height neodymium magnets (x12)
- 12V 5050 LED strip with adhesive backing, such as this
- 2.1 mm DC power jack to two terminals connector, such as this
- 12V 1A power adapter (center negative), such as this
- 2.1 mm inline DC on/off switch, such as this
- Sandpaper (I used 120, 220, and 400-grit wet/dry sandpaper)
- Screwdriver (or multi-tool)
- Scissors (or multi-tool)
- 3D printer with ABS filament
- CAD software (I used Fusion 360)
Step 2: .STL Files
At this point, you have two options:
Option 1: Download and print the parts I have provided
Option 2: Make your own parts
If you choose Option 1, download the files from this step and skip forward to Step 13. If you'd rather make your own, follow along and I'll walk you through what I did! I'm by no means an expert; this was a bit of a learning process for me. I'm sure there's a more efficient way to make the parts, but everything worked out in the end (and I learned a lot)!
Step 3: Dodecahedron Model
I used this excellent tutorial to learn how to make a dodecahedron. Follow along until you reach 4:46. When making the circumscribed polygon, I used a radius of 45 mm and did NOT dimension the sides of the polygon (0:54).
Step 4: Shaping
Our next step is to shape the dodecahedron. I wanted my lamp to be both low-poly and asymmetric, so there wasn't a lot of planning in this stage. Just play around until you like how the body looks (incredibly vague instructions, I know).
- I found that using the Chamfer tool (Modify ➡ Chamfer) is a good way to start out. Chamfer an edge or two.
- Use the Draft tool (Modify ➡ Draft) to create a more angled, asymmetric body.
- You can also use the Offset Face tool (Modify ➡ Offset Face) to "push" or "pull" on a face, extending or shrinking it. This is a good way to modify how the profile of the body looks.
- Keep using these tools until you're happy with the body. I ended up using Chamfer the most.
- Now you need to "hollow out" the model. Start by copying the body (Modify ➡ Move/Copy); check the Create Copy box and press OK.
- Hide one of the bodies. Open the Offset Face tool and select every face of the visible body. We want to make this the inner body, so enter a negative value for Distance. I recommend choosing -4.5 mm.
- Make the other body visible again. If we set the outer body to 50% opacity (Bodies [right-click the body] ➡ Opacity Control ➡ 50%) we can confirm that the inner body is smaller.
Step 5: Base
- Select the two bodies you modified in Step 4. Copy them and move them to the side. Hide the copied bodies for now.
- Enter the PATCH workspace. Take a second to look at your model. There should be a "seam" around the model where the angles of the faces change from "out and away" from the center to "in and towards" the center. This seam separates the base from the top.
- Delete the faces above the seam. This will expose the inner body; repeat this for the inner body. You will end up with two nested bodies, as shown in Image 4.
- We need to join the bodies together using the Loft tool (Create ➡ Loft). As shown in Image 6, select two parallel edges and press OK. Repeat this step, using Loft to connect all parallel edges.
- Open the Stitch tool (Modify ➡ Stitch). Select all visible surfaces, and press OK. This will join the faces together, creating a new body.
Step 6: Top
- Make the copied bodies from Step 5 visible. While still in the PATCH workspace, delete the faces below the seam; the opposite of what you did for the base.
- Decide which faces of the model you want to remove in order for light to shine out. Delete these faces. I would recommend deleting 3-4 faces with different sizes, angles, and locations.
- Like you did in Step 5, use the Loft tool to connect the nested bodies.
- Use the Stitch tool to join everything together.
- Return to the MODEL workspace.
Step 7: Plug Hole
This step is dependent on the shapes of both your lamp and your power jack connector. Try to position the plug hole away from edges and sharp corners, as this gives everything a better chance of fitting well.
- Determine which of the base's faces is the "back" of the lamp. This is where we'll put the plug hole.
- Use the Plane at Angle tool (Construct ➡ Plane at Angle) to create a plane through the seam where the back face meets the bottom face; see Images 2 & 3. It is important that the plane is at a 90° angle to the bottom face.
- Measure your 2.1 mm power jack connector (width, height, outer diameter, etc.).
- Create a Sketch on the new plane. Determine the clearances you'll need in order to make your power jack connector fit. In my case, I needed to create a 10.5 mm diameter circle (Sketch ➡ Circle ➡ 2-Point Circle) that was 2 mm above the bottom face.
- Use the Extrude tool (Create ➡ Extrude) to cut a hole through the back face.
Step 8: Magnet Holes
These holes are for the magnets we'll use to hold the lamp together. As such, it's important that they line up.
- Create a Sketch on one of the base's "seam faces," which are the faces that contact the top.
- Create a 3.175 mm diameter circle (1/8") (Sketch ➡ Circle ➡ Center Diameter Circle) centered halfway along the face lengthwise, with the center point 1.75 mm away from the inner edge.
- Use the Extrude tool to turn the circle into a 1/16" deep hole.
- Repeat. I found that using 6 pairs of magnets held the base and top of the lamp together quite well.
- Do the same thing on the top's seam faces. It's a good idea to set opacity to 50% and temporarily join the base and top together (Modify ➡ Move/Copy ➡ [move type] Point to Point) to confirm that the holes line up. Also make sure that the extruded holes don't extend through the outside of the top and base.
Step 9: Cover
The cover is important for two reasons. First, it diffuses the light from the LEDs. Second, it improves the appearance by hiding the guts of the lamp.
- Start by using the Offset Plane tool (Construct ➡ Offset Plane) to create a new plane 20-25 mm above the bottom face of the base.
- Create a Sketch on that plane. Create a rectangle that encloses the base when seen from "above" (Sketch ➡ Rectangle ➡ 3-Point Rectangle).
- Extrude that rectangle 2 mm upwards to create a new body.
- Use the inner faces of the base to "split" the rectangular body (Modify ➡ Split Body).
- Enter the PATCH workspace. Delete the faces of the rectangular body that are outside of the base; see Images 6 & 7.
- Create a Sketch on the cover. Draw a line (Sketch ➡ Line) across one of the corners, about 4 mm in from the point.
- Return to the MODEL workspace and use Extrude to "cut" the corner off at the line. This will make the cover easier to remove; you can now use your finger or a paper clip to lift it up.
Step 10: LED Support Part 1
- Use Offset Plane to create a new plane 15 mm above the bottom face of the base.
- Create a Sketch on that plane. Create a rectangle that encloses the base when seen from "above".
- Extrude the rectangle 15 mm down to create a new body.
- Use the inner faces of the base to "split" the rectangular body.
- Enter the PATCH workspace. Delete the faces of the rectangular body that are outside of the base; see Images 5 & 6.
- Return to the MODEL workspace.
Step 11: LED Support Part 2
- Extrude the bottom face of the base upwards to cut through the body you created in Step 10.
- Use Extrude to remove the section of the support that touches the face of the base containing the plug hole.
- Use the Offset Plane tool to create a new plane 2mm down from the top of the support.
- Use this plane, along with the Split Body tool, to create two separate bodies (the "top" and "bottom" bodies).
- Hide the top body, and create a Sketch on the top surface of the bottom body. Create lines parallel to the inner edge at a distance of 2 mm from said edge.
- Use Extrude to remove the parts of the bottom body that don't include the sketch you just created; see Image 8.
- Make the top body visible again. You should end up with a model resembling Image 9.
Step 12: Prototyping
This step is definitely optional, but I found it to be kind of fun. I made a couple different models, and made paper mock-ups of the two I liked the best. This is a good way to get a rough picture of what your lamp will look like once it's printed, and lets you make sure that the dimensions, etc. are correct.
Step 13: 3D Printing
I highly recommend using ABS rather than PLA for this project. LEDs can get pretty hot, especially in enclosed spaces, and PLA has a relatively low glass transition temperature (essentially the point at which the plastic starts to "soften") of around 60 °C. ABS, on the other hand, has a glass transition temperature of over 100 °C.
- Generate .STL files of your model (or download the ones provided in Step 2).
- Print the files. Unfortunately I didn't do the printing myself, so I can't speak to the specific conditions used. If you have the time, I would recommend using 0.1 mm layer thicknesses.
- Print the "Top" and "Base" files in whatever colour you want.
- Print the "Cover" and "LED Support" files. I recommend using clear filament if possible.
- Remove the supports and excess material from the prints. Make sure everything fits together as it should.
Step 14: Adding the LEDs
- Wrap the LEDs around the inside of the LED support, and cut an appropriate length off the strip. ONLY cut along the line between the copper "dots" that you see at intervals along the strip. See Image 1.
- Use the adhesive backing to secure the LEDs to the support.
- Connect the wires from the LED strip to the terminals of the power jack connector.
- Install everything in the base. The tip of the power jack connector should fit snugly in the plug hole.
Step 15: Testing
- Attach the power adapter and plug it into the wall. Inspect the LEDs to confirm that everything is working as it should.
- Fully assemble the lamp, and inspect it from the outside to make sure there are no significant dark or bright spots.
- Leave the lamp on for a while (at least 30 minutes) and check periodically to make sure the LEDs aren't overheating and the body isn't softening. If you used ABS this shouldn't be an issue, but it's worth checking just to be safe.
Step 16: Sanding & Adding the Magnets
I installed the magnets before sanding, which was probably not the right call. I would recommend sanding first. A word of warning; this will take a while! However, it's completely worth it.
- Starting with 120-grit paper, sand the parts using a circular motion. The lower grit paper is used to remove the "layer lines" from printing. Images 2 & 3 show a face before and after sanding with 120-grit.
- Move on to higher-grit sandpaper, and continue sanding until you're happy with the finish.
- If you want, you can use higher-grit sandpaper to give the cover more of a matte finish.
- Now it's time to add the magnets. I found it easiest to place the magnets on a flat piece of steel and use said piece of steel to push the magnets into the holes.
- MAKE SURE YOU INSTALL THE MAGNETS WITH THE CORRECT POLARITY. An easy way to do this is to stick two magnets together, and then use a pen to make a mark on their outside faces. This way, all you have to do is make sure the marked faces are the ones inserted into the holes. I recommend installing them on the base and top in their corresponding pairs, rather than doing all the base magnets and all the top magnets at once. This way you can confirm that you installed the magnets correctly as you go.
Judges Prize in the
Indoor Lighting Contest