Motorized Ouija Board

Our project is a school project that we were given, and told to develop a project that integrates at least many topics from advanced mechatronics, manufacturing, engineering mechanics, coding, and digital electronics. This project had to have a balance between complexity and feasibility, designed to be completed in less than two weeks. 

Our project ended up being an interactive ouija board controlled by magnets. The board utilizes a motorized system and tracks on its underside to manipulate a magnetic planchette. The motors are programmed to move in precise patterns, enabling the planchette to spell out various words. 

Some mechanics and features we used are: a mechanical system, magnetic interface, coding and control. The mechanical system is made out of tracks and motors that are mounted beneath the board. These serve as the control mechanism. The magnetic interfaces are made out of magnets being attached to the motorized system and will interact with a magnetic planchette. This will create the movement on the surface of the board. The coding and control aspect are created by coding the motors to execute specific movements, like spelling out words. 

Some constraints and considerations that we kept in mind are: design, clear integration, and aesthetics. Our design had to be efficient to assemble and debug in a short time span. We also needed to have a system demonstrate clear integration of skills across multiple disciplines. Our project also had to be functional, visibly aesthetically pleasing, and demonstrate a precise control of the magnetic planchette. 

This project will offer a creative way to showcase multidisciplinary engineering concepts while maintaining a manageable level of complexity, and we hope to show how cool engineering and creative thinking is.

Supplies - ALL

1. Hot glue
2. Acetate sheets
3. Wood
4. Magnets
5. 3d printer filament
6. Acrylic paint
7. Paint markers
8. Paper plates
9. Paint brushes
10. Spray paint primer
11. Gesso
12. Spray paint sealant
13. Circuit supplies
14. Legos
15. Sharpie
16. Arduino nano
17. Micro-Servo FS90R
18. Arduino IDE
19. Legos:
20. 6x Lego part 57878
21. 3x Lego part 57051
22. 3x Lego part 2878
23. 6x Lego part 32062
24. 3x Lego part 32013
25. 3x Lego part 32192
26. 18x Lego part 32123
27. 3x Lego part 32269
28. 3x Lego part 32498
29. 3x Lego part 6589
30. 6x Lego part 6590
31. 3x Lego part 3176
32. 3x Lego part 3023
33. 3x Lego part 3069
34. 3x Lego part 3937
35. 3x Lego part 6134
36. 1x Lego part 85489b
37. 1x Lego part 23948
38. 1x Lego part 32270
39. 2x Lego part 3832
40. Ferromagnetic ball bearing
41. Linear hall effect sensor
42. APPLAB ceramic magnets
43. 11 male-male wires
44. 3 female-male wires

Tools:

1. Canva
2. 3d printer
3. Circular saw
4. Computer
5. Google Stopwatch
6. Phone Slow motion camera

3D print files:

To begin, you would start by deciding the size of the ouija board. I would recommend going with something around 16 inches by 10 inches with a thickness of 1/4th of an inch. This drawing should just have basic ideas. I recommend creating another drawing of this. I would also recommend making the letters at least an inch wide and an inch tall. In this first sketch I was planning on making the letters one inch wide by 1 ½ inch tall, with 0.2 inches between each. You can put whatever you wish on the border and in the center. 

After creating this sketch, create a more detailed one. I would recommend one with colors, letters, and drawings. You can use this sketch as a guide. I didn’t fully follow along exactly with this sketch. However, it is helpful for having a guide to follow along with. I would recommend either using Ibis paint or Canva, these are both free tools that you can use. I used Canva for this, as it has a tool to curve the letters. It also has a tool where you can create a gradient in the background. 

Obtaining a board and preparing it

I would recommend either going to Home Depot or Lowe’s. I went to Home Depot and went to the plywood section and the paint section. I would recommend getting wood that is good quality. I got birch plywood that has a thickness of ¼ of an inch. You need a board that is at least 34x20 inches, so that you can cut it into two pieces 16x10, the set the other piece aside for later. You want to get a board that will not warp once you paint it. Then, get a white spray paint primer and a spray paint sealant. You could also buy a spray paint for the color that you want to make the board. Since I wanted to do a gradient, I went with acrylic paint.

Then use a regular saw or a circular saw and cut down the board to size. Once you do this you can use sandpaper and sand down the rough areas. Then, I would recommend using a primer and putting it on both sides of the board. Once you prime it, it should look something like this picture. This will likely take one or two hours to dry. 

Painting the Board

For the purpose of this project you only need to paint one side of one board. Even though you primed the board, I would recommend putting at least two coats of gesso on the board. Once those layers dry, get out the colors for the base coat of the board.

 If you want to do a gradient, spray half of the board with water. Then, get out at least three different colors of paint. I used four different colors of pink. Get out a paper plate and put the paint on the plate. You want to mix the first color with each of the other colors. This will make the gradient more aesthetically pleasing. When starting the painting process, you want to only do one half of the board at a time. For the gradient to look nice, the paint has to be wet for the entire time. Start with the darkest color and then work towards the lightest color. 

Then, get a colored pencil and sketching out an outline for a guideline for the letters. I would also recommend having at least a one inch border along all the edges or sides, to allow for computer error. Then, design the letters. I decided that each letter should be one inch wide and tall, and at least a 0.1 inch space between each letter. Then, sketch the letters on the board with a pencil. also sketch the words: “Yes,” “No,” “Hello,” “Goodbye.” If you have Poscas or other paint markers, then you can color the letters in with those instead. 

After you get the letters the way you want them to look, start on sketching the border and the drawing for the middle. Once you create this sketch, start blocking colors. I also added a few flowers to the border, while waiting for the paint to dry. 

There is a very easy technique to paint roses. You take a rounded brush and dip one side into a lighter color and one into a darker color. Then, you make two little curved lines. paint these small ones with a lighter color inwards. Then, you can make as many rounded shapes that you want on the edges of the two small lines. When doing these, you hold the brush so the lighter color is on the outmost edge. Then, you can go in white a white paint marker and add some highlights, as needed. 

To paint lilies, you can take a rounded brush and make a few teardrop shapes that all connect to each other. Then, you can take a slightly darker color and add a few lines coming from the center of the flower outwards. To do this, I would recommend watering down the paint slightly. You can also do this to the outside of the flower with a lighter color. You can take a small brush with a darker color and add a few dots to the center. This will give you a very pretty lily. 

Once you block the colors and start on the border, you can start adding more details. I added cats, so I started detailing the hairless cat. If you do want to paint a hairless cat, you need to mix a darker and lighter color for the highlights and shadows. Then, you will need to water down the paint quite a lot. This will help the paint glide. I then used a very small brush and added some irregular shaped lines. If you have painted a tree or watched Bob Ross draw tree branches, the technique is very similar. 

If you want to paint a very fluffy looking cat, like the one below, then I would recommend using a rounded brush and a paint marker. You can use the round brush to add dots to the body of the cat. This will make it appear like the cat has fur. If you want the cat to be a type of Himalayan cat, then you can use the gradient technique from the board and do it on a smaller scale. Also, you can use a black paint marker and use it to draw the cats a nose and mouth. 

Next you can start on the details of the face. This part is very difficult, I would recommend practicing drawing eyes and noses on either a piece of paper or on cardboard. I wanted my board to be very monochromatic, so I decided to make the eyes pink and red. However, you can make yours any color you want. Also, you don’t have to draw a cat on the board. Make the board to your taste. I would also recommend drawing the eye shape and nose shape with a colored pencil. This will give you a nice outline to work with. Then, all you have to do is block the color and add pupils. For the pupils, you can make a diamond shape. For the nose, you can make either an oval shape with a small oval in the center or you can draw a slight heart shape with a small oval connecting to the mouth. 

Then, you can add fur strokes and whiskers to the cats. I would recommend taking a lighter color and a darker color. Then, you can water down the paint slightly and add some strokes to the face and tail. You can do this with white paint for the whiskers as well. You can also do this with a darker color and add an outline around the fluffy cat. This will make the cat stand out against the board. You can also take some paint and thin out the mouth area, if it is too thick. Additionally, if you feel the mouth and nose is too dark, you can outline them in either brown, burgundy, or dark grey. This will make the mouth and nose feel less harsh. 

Then, you can add some flowers and leaves to the cat's head. You can use pink, red, and gold paint markers for this. You could use a paint brush to create the flowers, however for such a small scale I would recommend using paint markers. To create roses with paint markers, you can follow the same process as before. However, instead of dipping half the brush in a light and the other half in a dark color, you can take the dark color, then go over the edges in a lighter paint marker. This will create the same effect. Add some lights and darks and add some speckles to the middle. To tie everything together, you can use a gold paint marker to add some detailing around the edges. You can create swirls and patterns. 

One of the last steps is to take an eraser and go back in and erase the pencil lines. It might not remove everything, so you can cover those areas with some decoration. 

Then, the last thing you need to do is either spray the board with a sealant a few times. You can do this until your board is smooth enough for your liking. Or you could go in with some modge podge and cover your work. This will seal everything in, so nothing will get chipped or smudged. 

Next add a sheet of acetate or clear plastic to both sides of this board if it is still not smooth enough. It will also limit the amount of friction the magnets will produce later on. You can use any clear glue to glue this on. Then, just cut off the extras. 

These are things that will be required to be 3d printed for this project to work. they are linked in the supplies.

for this project you will need:

1. 4x legs,
2. 4x long tracks
3. 3x track stopper 1
4. 3x track stopper 2
5. 3 Lego--> servo adapters

the four legs are designed to go on each of the corners of the board, and should be glued to the base board, but left unglued to the fancy board on top for easy access to the inside. The tracks are designed to be compatible with Lego train and gear parts, as well as to fit together, so be sure to use an accurate printer for best effect. All the parts are printable with very little support filament, so be sure to print them laying flat, the Lego --> Servo adapters

to print them, download the stl onto your device and find the 3d printer you want to use, Then download whatever programs are necessary for using that printer. Upload the STL to that software, and hopefully the software will convert it to usable code. For example using a prusa mini and their program prusa slicer, where we uploaded the STL and it output bgcode.

Things you will need for this step:

1. All the Legos
2. Our custom lego to servo adapter
3. Micro-Servo FS90R

This base will be made 3x

Take the metal bar and two small train wheels, attach the wheels to the bar.

Take the train cart and attach the bar to the button, it should have a slot to push the bar into

Take a 1x6 brick and put it on the left side of the cart

Place the axle to brick adaper on top

Push an axle through the adapter

Put an angled axle connector on the axle

Put an small notched axle in the angled connector , making sure to only push it into the first adapter

Push a spacer onto the notched axle

Put on the one sided connector with a hole on the end to the other end of the notched axle piece

 Push an axle through the end connector and use a small spacer on the outside and a large on the inside

Do the same thing but with the upper connector hole

Put the small gear onto the lowest axel and push a spacer onto the end

Put the large gear onto the highest axel and push a spacer onto the end

*side build*

       Push a spacer and a bevel gear onto a notched axle

Attach the adapter to the spacer side of the notched axle

Attach the servo to the servo side of the adapter, it should hold with just friction but if it doesn't apply a small dot of glue

1. Glue the servo onto the 1x6 brick, with the bevel gear meshing with the large gear

1. Attach the 2x3 tile on top of the studs to axel adapter

1. Put the bottom of the hinge, the 1x2 tile, and the 1x2 plate on top of the 2x3 in this arrangement

1. Attach the top of the hinge to the bottom

Now that we have the base for all three carts done, set two aside for the moment. With the third one replace the lowest axel with a longer one, and attach the small bevel gear, and the train wheel, to the same side as the gear already there. It should look like this: 

You should also glue on a magnet to the hinge top. This will be to hold the ball bearing and move it to the correct spot.

For the other two, put one end of a 2x10 plate on each, facing in opposite directions, this will be glued on to the 2x16 board

for this you will need all the wires, the arduino, and the linear hall effect sensor. To wire the motors, just connect your grounded wire to the brown/black wire, your power wire to the red wire, and your pin input on the arduino to the orange wire, this will have to be the same pin as specified in the code, or it will not work. this means that d8 and d11 will be used for the bottom carts and d12 for the upper one. the linear hall effect sensor will be connected to d6

1. to start off glue take two tracks and glue stoppers to each end, then glue these tracks 1 cm from the edge on all sides.

.

Take all four legs and glue them up against the side of the board, these will hold up the painted board, but do not glue them to it.

Next, take the two remaining tracks and glue them together, putting the remaining stoppers on each end.

glue this to the set aside 2x16 board, centered, the stoppers should just hang over.

Take the two similar carts and place them on the tracks glued to the big board, on the same line, then glue them to the underside of the 2x16 board

take 5 of the ceramic magnets and glue them to the edge of the board, pressing against the corners, these should be on the same side as the gears

it should look like this when done:

Our code uses a coordinate system to find it's position and move to the next letters, Paste this into Adruino IDE and connect your computer to your arduino board, then hit upload. if you touch a magnet to the sensor, It’ll then pick a random one of the prompts to choose;

Old

Young

Alone

Angry

Sad

Hurt

Yes

No

*Important note*

this will only work with the exact dimensions listed, if you want a different sized board you will have to edit the code manually

Place the board on top and put the ball bearing over the magnet, plug in the arduino and enjoy!