3D Printed Tardis With Sound and Fading Lights

Hi all, in this instructable, I show you how to construct a Tardis that plays music and has fading LEDs to emulate the real thing. I chose to do this project because I have loved Doctor Who since I was a kid. I chose to use a Tardis based on the 10th Doctor's along with the intro music from his seasons, because they were the first episodes I watched and are some of my favorites.

Filaments

• ~1KG Blue Filament
• ~50g Clear Filament

Electronics

• One 2N2222 Transistor
• One 22uf Capacitor
• One 5V Regulator
• One 555 Timer
• One Switch
• One 390 Ohm Resistor
• One 20K Ohm Resistor
• One 150 Ohm Resistor
• One 5mm Blue Led
• Any size Micro SD Card (I use 32GB but songs are only a couple MB)
• One 70mm x 50mm Protoboard (Or any size that you feel comfortable sautering all the components on)
• Male Dupont Headers
• 9V Battery Case
• One Magnet Speaker (I use 2W 8 ohm but I think other types should work)
• One TF MP3 Decoder
• 5V White Led Strip (Long enough to go around the inside of the Tardis)
• Plenty of wire, I like to use solid wire for PCB's and stranded wire for everything else.

As a starting point for making the Tardis, I used this design by countspatula on Thingiverse: TARDIS Deluxe Kit by countspatula - Thingiverse. I used their files for the main body of the Tardis as it left the inside hollow for me to place the flashing light and music player circuit. I printed all the parts besides the OLD, led holder, and switch holder. Along with this, I added a plate to cover the electronics and scaled everything up to 200%. My printer had a larger bed but this may not be possible on smaller printers, so you may need to print the larger pieces in parts or scale down the plate I designed.

To create the circuit, you will need the 2N2222 Transistor, the 22uf Capacitor, the 7805 5V Regulator, the 555 Timer, the 20K Ohm Resistor, the 150 Ohm Resistor, and dupont headers. Along with this, you will need wires. I used solid core wires to create rails on the top and bottom of my proto-board and used a combination of solid core wires and solder tracks to connect everything along the back of the board.

This circuit works because the 555 timer outputs an oscillating pulse signal that switches between on and off states at a frequency and wavelength dependent on the circuit's resistors and capacitors. This allows the fading effect for the LED and LED strip.

After assembling the circuit, you can test it by connecting the 9v battery to the positive and ground rails on the board and connecting an LED to the 5v pulse and ground dupont connectors. The LED should fade in and out at a reasonably fast speed. If you want to change the speed that the LED fades in and out, you can alter the values of the resistors and capacitor in the circuit.

After creating the initial circuit, we'll want to start adding our main components. I started with my decoder and speaker section. For this, you'll need the Micro SD Card, The Magnet Speaker, and the TF MP3 Decoder. Start by soldering a ground wire to the SP- pad and a positive wire to the SP+ pad on the bottom right of the decoder. After, solder those to the respective ground and positive pads on the speaker. Now, solder a positive and ground wire to the pads labeled GND and BAT+; the wires you use should have a way to connect to the protoboard on the other end, whether its a dupont or you want to solder it (I used duponts). After the wires are soldered, connect them to the protoboard at the "to speaker" labeled area. Finally, find an MP3 of a Doctor Who theme or sound you like and download it (I attached the one I used to this step), then add it to the micro SD card. You can now insert the SD card into the decoder, and when it's powered, it will play the sound through the speaker.

After the decoder, solder positive and negative wires to a ~12-inch 5v white led strip. The wires should have duponts or another type of connector on the end going to the protoboard. After the wires are soldering, attach the wires to the 5v pulsing rail to make the led pulse with the music.

Next, we will need to wire up the led diode that will fade at the top of the Tardis. You will need a 390-ohm resistor, a 5mm blue led (or a 3mm one if you want to use extra hot glue to hold it in place), and wires. Start by soldering the resistor to the cathode on the led. Next, attach a positive wire to the other end of the resistor, and a ground wire to the anode of the led. Cover these connections with either heat shrink or electrical tapes to insulate and protect the connections. After attaching the wires, either add dupont connections to the end and connect them to the 5v fading and ground rails on the protoboard or solder them directly to those connections. This will allow the led to fade in tandem with the led strip.

Solder a positive wire to the 9v rail and a ground wire to the ground rail on the protoboard. Do not connect these wires to the battery yet, as they will need to be routed first.

On one of the tardis walls, drill a half-inch hole in the bottom right panel. This will be where the switch is inserted, and this wall will be used as the back wall.

Now, we will need to attach the window panes to the tardis walls and door. Start by adding a small strip of hot glue just under the window holes on the tardis door, then press the widow pane into place and allow the hot glue to set.

Here is where things will get a little harder to assemble. To start assembling the body, line the door and one wall (not the one with a hole) up with each other, making sure the door is on the right side. Then hot glue the led strip just below the window on the door. Next, add a strip of hot glue in the crack on the left side of the door panel, and slot the wall panel into it. Now, hot glue more of the led strip below the window panel. Repeat this for the third and fourth doors, making sure the third wall is the one with the switch hole.

Take the square base and slot the main body into it. It should take a slight amount of force and will slot in firmly.

Next, we will need to attach the cover plate to hide the majority of the electronics and give them something to rest on. Start by lining up the slit in the cover with the hole in the side of the tardis door. Leave about a quarter-inch to a half-inch of space between the cover and the switch hole. Then, hold it up by the middle hold and hot glue around the edges. Try to keep it as straight as possible, however, the only time this will be seen is when you change the batteries, so it's not super important.

Now, we will need to connect the battery to the switch. Start by adding two somewhat short positive wires to a middle pad and a side pad on the switch. Next, push the wire through the hole and glue the switch into place against the wall. After the switch is in place, take the 9v battery pack and solder the positive wire to one of the wires on the switch, it doesn't matter which one. Then, push the ground wire through the center hole and the leftover positive wire through the side slit.

After connecting the battery and the switch, connect the positive wire coming off the switch to the positive wire on the protoboard and the ground wire from the battery to the ground wire on the protoboard. This will provide all the power for the electronics. After securing those connections, we will need to secure the protoboard. Add some hot glue to the back of the protoboard and place it against the top of the cover plate. Allow the hot glue to set, and the electronics will be secure!

Push the speaker through the small slit, then secure it to one of the inner side walls of the Tardis.

Finally, we will attach the roof. Start by snapping the upper roof part into the roof frame part. Mine fit very tightly and needed a bit of force to snap in fully, so don't be too afraid to use force. Then, hot glue the led cover and the top cone together. Next, use enough hot glue to secure the led into the led cover. It will need a lot due to the model having been doubled in size. Lastly, glue the led cover into the slot on the roof.

And there you have it! A miniature Tardis that can play a little theme and put on a light show! Overall, this project was relatively simple and only required basic soldering skills and a 3d printer, which means that it's easy and straightforward to make and show off your love for Doctor Who.