Planet Spinner, a Magical Orrery?

Get ready to revolutionize the way you experience the solar system with my brand new invention - the incredible, Planet Spinner! This tiny device, once a day at midnight, moves the planets to show their correct orientation around the sun. Unlike traditional orreries that only show the relative speed of motion of the planets, this device is designed to show the correct orientation. And the best part? You can easily make your own using just a laser cutter and some off-the-shelf electronics - it's that simple!

What sets the Planet Spinner apart from traditional planetariums is the innovative mechanism that's inspired by vault locks. This mechanism, which has never been used in a planetarium before, is incredibly simple yet effective. It took me 2.5 months, 20 prototypes and multiple motors to develop, but the end result is truly amazing!

I've named it the Planet Spinner because that's exactly what it does - it spins the planets in their correct orientation. It's the perfect device for anyone who's passionate about astronomy or just loves cool gadgets.

The Planet Spinner is the latest evolution in planetarium technology. It builds on the legacy of the oldest working wooden planetarium in Franeker, created by Eise Eisinga in 1774. Like traditional orreries, the planetarium is very complex and uses a lot of gears. In contrast, the Planet Spinner is designed to be simple, effective and the world's smallest wooden planetarium. It's a testament to the power of simplicity and innovation. And thanks to its direct data feed from NASA, the orientation of the planets is always up-to-date and precise.

So why settle for anything less? Build your own today and join the revolution!

• a piece of 1.5mm basswood 125x150mm
• this tiny stepper motor https://www.aliexpress.com/item/4000538374661.html (150 ratio type)
• a TMC2209 (not 2208!) stepper motor controller board like this one https://www.aliexpress.com/item/1005004604384978.html
• this amazing processor board, an ESP32 C3 with https://www.aliexpress.com/item/1005004865447043.html (the display isn't really needed, but it came with it, so I programmed for it anyway)
• half a dozen of old fashioned toothpicks
• eight very tiny safety pins. These are about 18mm long, but more importantly they are pretty strong and made out of 0.45mm wire.

You need a soldering iron, sanding paper, wood glue, a pair of cutting pliers and access to a laser cutter to make it.

The first step in building your own Planet Spinner is easy and fun! Simply grab a laser cutter and a piece of 1.5 mm thick wood measuring 125x150mm, and let's get started!

Engrave the front using the first B&W image. The white background of all the B&W images has the exact dimensions of 192x192mm, so use that for the correct scaling.

Each letter on the engraving corresponds to a specific part and signals which side is the front - making the construction process even more straightforward.

Leave the material in the laser cutter. Next use the second image to cut a small square around the planets, remove the square, and flip it around so we can engrave the symbols on the back.

Once you're done with that, flip the square again and place it back so the front side is visible. Finally, use the last image to cut everything out. Just be careful not to lose any of the small planets - they may be tiny, but they're important!

Congratulations, you've now completed the first step towards creating your very own Planet Spinner. So let's keep going and bring this amazing creation to life!

(my 1.5mm basswood sheet, was actually more like 1.6mm. I tried to design the Planet Spinner in such a way that in most places the precise thickness is not too much of a problem, but sometimes you might need some sanding paper to make things fit).

Let's dive into building the base! To get started, grab some smooth and splinter-free toothpicks - you'll need three of them and insert them tightly into disk A. Next mount part B, C and D over it, using some wood glue. The three M parts are glued on top of D and are used to keep the display upright.

Next take another toothpick and glue the two disks labeled J on one end. Glue this construction on the back side of disk A (it will be the top side).

Glue gear H to the zodiac disk. Together they should rotate freely around the J disks.

Before we continue with the top, lets finish the bottom with the motor and the electronics in the next step.

Let's tackle the Motor Frame step! This one is a breeze. Start by inserting a two toothpicks into part E and then glue part F in place. Once the glue has set, trim the toothpicks on the F side and sand them down so they're flush with the surface. Now, on the other side of part E, simply slide the motor onto the toothpicks, taking care to note the orientation of the tiny PCB on the motor itself. Next, push gear G over the motor axis, making sure it's a snug fit but with a tiny bit of space left between the wooden motor frame and the gear. And with that, you've completed the Motor Frame step!

Let's get electronic! This step is all about setting up the brains of the Planet Spinner. You'll need two printed circuit boards, one with the ESP32 and another with the 2209 controller. Don't worry, it's not as complicated as it sounds. All you need are a few wires, which you can easily connect to the boards. To make things easier, use very thin wires like the ones that come with the motor.

First, you have to carefully loosen the display from the board, but only so it is still connected. According to the seller, the display is attached to the board using super glue, but it must be very bad super glue. To me it looks more like double sided tape. Still you have to go slowly and carefully, as you don't want to damage the display. I just used my nails to do it. I left the glue/tape on the display.

Next, let's work on the 2209 board. It comes with pin headers, but they take up too much space for the tiny Planet Spinner. So, completely remove the ones for TX, RX, and CLK. Don't worry, we won't need them. You can also cut all the other pins, except VDD and GND, which we'll use to power the machine. On the backside of the board, connect VM to VDD, GND to GND, and MS1 to GND.

Now, let's connect the 2209 board to the ESP32 board. Connect DIR to pin 3 on the ESP32, STEP to pin 4, MS2 to pin 7, and EN to pin 8. The ESP32 board gets power by connecting its 5V pin to VM on the 2209 board, and its G pin to the GND on the 2209 board next to it.

See, that wasn't so bad, was it? Just follow the pictures, and you'll be all set.

Now, it's time to connect the motor! This step is a piece of cake. Simply cut the wires to the appropriate length and connect them in the order of white, red, yellow, and black to the pins 2B, 1B, 1A, and 2A, on the 2209 board as shown in the picture. It doesn't matter on which side of the pcb you solder the wires, both work just fine. You may be wondering, "What's the right length?" Well, the best way to determine that is to fold the electronics around the motor, just like in the picture. To ensure there are no electrical issues, I've added a layer of insulating tape around the end of the motor. Although it's unlikely to cause any problems, the tape provides some extra protection and peace of mind.

Start by placing the motor and the folded electronics boards into the wooden base. You'll notice small notches in the base that should hold both PCBs in place. Take Part L and slide it over the toothpicks, ensuring that it secures the motor and electronics firmly in place.

Next, it's time to cut the legs to your desired length. Longer legs will make the Planet Spinner look like a mini table, while shorter legs will give it a more compact and stable appearance. Make sure to leave at least 1.5-2mm of clearance to accommodate the power cable.

Once you've trimmed the legs, take a moment to ensure that everything is securely fastened in place. This will help prevent any wobbling or movement during operation. With the motor, electronics, and legs in place, your Planet Spinner is almost ready to go!

On the backside of the Zodiac disk, you might have noticed a tiny hole nestled between Gemini and Cancer. Take one of your trusty safety pins and gently bend it straight. Then, carefully rotate it back and forth through the hole - no pushing allowed, as we don't want to damage the wood. Once the pin is in place, cut off the sharp end and leave a 3mm peg. Use the little disk with the sun on it and push it gently over the toothpick. This will securely hold the Zodiac disk in place while still allowing it to rotate freely.

Let's talk stepper motors. One thing to keep in mind is that they don't know their exact orientation when first powered on. This is why many stepper motor applications have switches to define the home position. I originally implemented this feature in my first prototypes, but then I had an epiphany: why not attach the motor directly to the Zodiac disk instead of one of the planets? By spinning the disk itself, I could essentially establish the home position without any extra fuss.

So, let's take advantage of this clever little trick, and continue with building up the solar system.

Time to add some planets to the system. Get the disks with the long arms to hold the planets. Ignore the two biggest ones, as they are for the "grand" version which we are not building today. (see my other instructable for the Grand Planet Spinner). Use seven more safety pins and bend them straight. Slowly rotate them into the hole at the end of each arm and cut them to length. Better a bit too long as you can always shorten them. Next push the planets on top of the safety pins. Be very careful as you might easily split the wood. Instead of pushing them onto the pins, you might consider drilling a tiny hole at the bottom, and use some super glue. Dip the tip of the pin in the super glue and put the planet on top. That's what I did.

Start with Saturn, and put it on the toothpick. Make sure it can rotate without any problems, then add a spacer disk to hold it in place. Check again that it can still rotate freely. Then continue with the other planets. For good esthetics, use the smaller disk to hold Mercury in place.

Now it's time to snip off the top of the toothpick. For the little sun, you can either glue it flat onto the smaller disk or use your last safety pin to drill a tiny hole in the top of the toothpick and glue the pin and sun in place. Just make sure the center of the sun is slightly above the top of Mercury, so it doesn't bump into the sun's rays. Your solar system is now complete and ready to shine!

Let's get to the exciting part - programming! To get started, you'll need to download Arduino IDE (https://wiki-content.arduino.cc/en/software/) and connect your Planet Spinner to your computer with a USB cable.

Once you've installed Arduino IDE, go to File/Preferences and add "https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_dev_index.json" to the line after "Additional boards manager URLs." Then select "ESP32C3 Dev Module" as your processor and specify the USB com port your Planet Spinner is connected to.

To get your Planet Spinner up and running, you'll need to install a few libraries, including TMC2209, U8g2, OneBitDisplay, BitBang_I2C, and ESPAsyncWebSrv. You may also need to install ESPAsyncTCP and AsyncTCP.

Once you've installed the necessary libraries, download the PlanetSpinner.ino file and open it in Arduino IDE. Then edit lines 5, 6, and 9 with your network name, password, and timezone.

Next, compile the code and send it to your Planet Spinner through the USB connection.

Congratulations, you're now the proud owner of a fully-functional planetarium!

Let's add some style to the base of our planetarium! This is where your creativity can shine through - there are endless possibilities for materials and designs. I personally went with a vinyl that had a stunning copper look, and also made a version using some beautiful fineer. You could even use a unique piece of paper that catches your eye!

Cut your material using the B&W image.

If you go with the fineer option, all you need to do is bend it over some steam and it will curl almost by itself. Just a word of caution - if you choose to use vinyl, do not cut it with the laser cutter as it creates aggressive and toxic gasses. Use a sharp knife instead.

Once you have your material glue together to make a nice circle. Make sure it's a tight fit so it stays in place just by friction. Simply slide it over the feet from the L part and voila - your planetarium now has an added touch of elegance!

The clunky USB connector on the Planet Spinner didn't quite fit the sleek and polished look that I was going for, but fear not! This is where the two pins on the TMC2209 board come in handy. Take an old USB cable that you have lying around and cut off the connector. You should see four wires, two of which are probably red (5V) and black (GND). You can double-check the voltage with a multi-meter if you have one, just to be safe.

Now, take the black wire and connect it to the pin in the corner of the TMC2209 board, and the red wire to the pin next to it. If you're feeling adventurous, you can even solder the wires directly to the pins. But if you're like me and prefer an easier solution, you can make a little plug using a female pinheader. I made mine three pins long, so I never have to worry about inserting it the wrong way.

The finished cable goes between the L part and the motor to the side of the Planet Spinner.

But, a word of caution: never connect both this cable and the USB port on the ESP32 board at the same time, as this could potentially damage your computer.

Congratulations on completing your very own Planet Spinner! You're now the proud owner of a sleek and polished planetarium that will mesmerize and amaze anyone who sees it in action. Enjoy the wonders of the universe right from your own home!

Wow, not only does this mighty tiny planetarium move the planets into the correct orientations, but it also has a fantastic web interface! When you power it up, it displays the IP address it got from your router on the display. Simply enter that address into your browser followed by /planetspinner, like 192.168.0.72/planetspinner, and you're ready to go! You can set a new date on the webpage, and your Planet Spinner will happily comply with your request. NASA supports any year between -9999 and 9999, so you can explore the night sky from any point in history or the future! How cool is that?

There is even a special button to select a geocentric view of the solar system. In this case the earth is in the center of the device and the sun takes the position of the earth. The planet orientations will be slightly different as now it shows the direction of the planets and the sun as seen from earth. Great if you are into astrology (I'm not) or want to check on conjunctions like the one from almost 250 years ago 8-may-1774.

Could the mechanism of the Planet Spinner be used to show the correct positions? yes it could but it needs to get bigger. With a diameter of 11mm for the orbit of Mercury, the orbit of Saturn would be 276mm. Surely feasible, but not very tiny anymore. But who knows in the future I might make one.

If you enjoyed following along with these instructions, please consider subscribing to my channel on YouTube at youtube.com/@illusionmanager or showing your support by buying me a coffee at https://ko-fi.com/illusionmanager. Thank you for joining me on this fun and creative project!

Be creative and do use this Planet Spinner mechanism to completely recreate it on for example a 3d printer to make a bigger one, or even build one out of lego's. It should be pretty easy. Please refer to it as "Planet Spinner by illusionmanager" and share your result here anyway!

(image from one of my prototypes where the zodiac disk was still static)