Introduction: Plywood Lamp With Hidden Switch and APP Control
Hello, and welcome back to my workshop! Today let's see how I made this wooden lamp, which is much more than just a lamp though. It includes smart home funcionalities, and it can be controlled via the phone app and the lamp itself can control the other lights in the house. The design of this lamp is very simple, and it integrates perfectly in a minimalistic looking home.
The woodworking part is very easy and it requires only basic tools, electrical part is as easy as connecting some wires.
To see more details about the construction, watch the video on YouTube (it is in Italian but it has English subtitles).
- 6 10x10 cm pieces of 15 mm okumè plywood (or other plywood you like, I choose this due to the dark red color)
- Transparent wood varnish
- Light bulb holder
- Led filament light bulb
- Shelly 1 smart relay or equivalent smart relay
- Texile power cord
- Two pole plug
- Limit swtich (rated for 250v)
- Rubber feet
- Connector blocks
- 40 mm Forstner bit
- Eelectric sander and sandpaper
- 3D printer (you can also do this project without having one)
- Paint brush
- Soldering iron
Step 1: Choosing the Wood
Let's start with the construction of the wooden base of the lamp. The base has this cube shape, which will be made by putting several pieces of wood on top of each other. I chose to use 15 mm okumé plywood because it has a color that I think is very beautiful. The cube will be made with 6 pieces of 10x10 cm, so I went to the hardware store and had them cut. The only piece that will have exposed grain will be the one on top, so I chose the one that I thought looked best. This one will have a hole, in which I will put the lamp holder.
Step 2: Drilling the Hole
I will use a 40 mm forstner drill bit to make the hole in the top piece. Such large drill bits have the problem that they slip on the wood, so I found a DIY solution for that. I cut two pieces of 4 mm plywood as big as the square of wood. I put one underneath, then I put the piece where I have to make the hole, then another piece of plywood, and finally this 3D printed piece. This piece has a hole in the center the size of the bit, and the sides are 10 cm, so we are sure to make the hole centered. I clamped everything to the bench with clamps and made the hole. The 3D printed piece kept the bit centered, and the two pieces of plywood kept the wood from splintering. After removing the clamps the hole came out perfect.
Step 3: Cutting the Base Pieces
In the pieces below, there needs to be some space for the lamp holder and electrical connections. So in these I am going to make a square hole that leaves around only a border of about 1 cm. To do this I created a template to drill 4 holes at the 4 corners of the square we need to cut. Once I made the holes in the okumé pieces, I joined them together with lines. Following these lines, I cut the square with a hacksaw. The cuts on the inside will not be visible, so they do not have to be perfect. The only one that will have to be a little precise is the one on the piece that will stand at the base. Due to this I finished it with a rasp and some sandpaper. After quite a bit of work, here are the 5 pieces with the hole on the inside.
Step 4: Gluing
Before moving on to gluing, I drilled a 7 mm hole in one side of one of these pieces, which will be used to run the cable through. And now comes the most difficult part, which is to glue the 6 pieces of plywood together. Starting with the piece that will be at the base, I glued the pieces on top of each other with wood glue. I lined up the pieces using a scrap piece, and put clamps to keep them pressed together.
Step 5: Sanding
The next day the glue was dry, and I removed the clamps. Although the pieces are well aligned, the edges of the plywood have some imperfections. So now on to sanding, to make the cube perfectly smooth. I started sanding with 120 sandpaper, to remove the small steps between the glued pieces and the glue residue. I used a sander to sand, because it makes the work faster and more precise. Then I went over everything with 180 sandpaper, to get a perfectly smooth finish. Finally, I sanded the edges of the cube by hand, to round them just slightly, but not too much.
Step 6: Painting
Now we can paint the cube. As a finish I will use water-based clear varnish, which protects the wood and gives a really nice color to the grain. I gave the first coat with a brush, and once it was dry I gave it a light sanding with the 180 sandpaper. Then I gave the second coat, trying not to leave any paint drips. Now the varnish is dry, and the okumé wood with the clear varnish has a really nice effect.
Step 7: Power Cable
To connect the lamp to the socket I used a fabric covered cable, which I think looks very good. I chose the light blue color, but there are many colors. To one end of the cable I connected a plug, and I threaded the other end through the hole behind the lamp.
Step 8: Smart Relay
The lamp will have a Shelly smart relay inside, which will allow us to control it from the app and integrate it into a home automation system like Home Assistant. We can also control the lamp via Alexa or Google Home. The smart relay I suggest is the Shelly 1 v3, which has the possibility to control other relays directly via WiFi. The one I used, the Shelly Plus 1, doesn't have this function, so keep this in mind if you plan to control other lights with the switch that's integrated in the lamp.
I connected the power cable, the light bulb holder and the switch (we will see it in step 9) to the smart relay by following the schematic.
Warning:these electrical connections are going to be connected to the mains grid, so be very careful when you make them and plug the lamp in only when it is closed. To make everything safer, ask a professional electrician for help.
Step 9: Hidden Switch
So we can move on to the electrical part, and that strange invisible switch you saw at the beginning, that turns the lamp on and off by pressing on a corner to make it tilt. Behind this magic is a limit switch mounted under the lamp. I soldered two wires between common and normally open of the limit switch. I screwed the limit switch into a corner of the lamp base so that it is aligned with the edge. I connected the limit switch between phase and SW contact of the smart relay, following the schematic in Step 8.
Step 10: Light Bulb Holder
To attach the lamp holder to the wooden cube, I made a 3D printed holder, which allows me to screw it behind the hole we made at the beginning. If you don't have a 3D printer, don't worry, you can make this part using wood. You will find the .stl file below.
Then I put the smart relay inside the lamp, and to protect the connections I 3D printed a cover to put under the lamp. As a last thing I put three rubber feet in the three corners except the one where the switch is. This will serve to raise the lamp just a little bit, so that if we press one corner of the lamp, the lamp will tilt and press the switch that is underneath. For me, this mechanism to turn it on and off is the best thing about this lamp, because it is completely invisible. You can find a demonstration of the switch mecanism in this video: https://youtu.be/B7_dWIJkNIA
Step 11: Smart Relay Configuration
Now that everything is complete we have to configure the Smart Relay we have put inside the lamp. This may vary depending on what smart relay you choose, and you can find the instructions to connect it to the app in the manual inside the box. However, if you are using a Shelly relay, you will have to set the input switch to momentary, so the lamp is turned on when you click the hidden button and turned off when you click again.
Also, if you have other lights in your home connected to these smart relays, you can control them by holding for two seconds the hidden switch of this lamp. To set this you can open the Shelly app and select your device. Under I/O actions, enable Button long push and insert here the local url that toggles the Shelly of the other light you want to control.
Step 12: Finished
Our lamp is finished, and it turned out super cool. To complete it I screwed a big filament led lamp in the bulb holder. If you need more information, please click here to watch the video on my YouTube channel.