The Useless Machine

As we navigate through the winding road of our lives, endlessly striving for freedom from the systemic strings that bind us to our roles in society, we occasionally need a reminder that it is all for naught. That no matter what buttons we press, choices we make, it always leads us to the same inevitable fate, the same place where we began. To solve this problem, we made a wooden box with a switch attached. When you flip this switch, a lid opens, an arm extending, and the switch is flipped off. Why? They’re very entertaining, and it's an easy idea that you can make for fun.

Also, my partner and I are high school students, and we made this for a project. We unfortunately ran out of time for this, and the physical part is not entirely complete. We both apologize, but hope you can still have fun with this project.

1. Plywood; half centimeter think, 15” by 12” 
2. 1x Arduino Uno 
3. 1x Small Breadboard
4. 3x Servo Motors 
5. 20 Male-Male Wires 
6. 7 Red
7. 9 Black
8. 1 Green
9. 1 Yellow
10. 1 Blue
11. 1 Purple
12. 1x Toggle Switch (NNK WT-11) 
13. 1x Rocker Switch (NNK JW-M21) 
14. 2x small hinges, probably 8x10mm
15. Band Saw 
16. Circular Saw 
17. Drill Press 
18. 3D Printer and A filament of your choice 
19. Parts to Be Printed: 
20. 3x Servo Motor Compatible Gears
21. 1x Gear Rack for lid
22. 3x Mount Plates for gear racks
23. 2x Gear Racks for the Arm
24. 4x Arm Pieces
25. 2x 3 stud length Lego Technic Axles
26. 6x 4 stud length Lego Technic Axles
27. 8x One stud diameter Lego Technic Wheels
28. 13x Mushroom Stickers (Optional) 

For time sake, it's best to 3D print first. These printed pieces are gears for the drive train for the arm, and the pieces to make the arm move. All stl files are linked, as well as an assembly of the final product. It's important to note these were made using Onshape.

Find the closest piece of plywood half a centimeter thick, and make sure it’s at least 15”x12” piece, leaving room for error 

Draw out four 4”x8” rectangles. Take the third one and draw a line down the center. These will be all four of your side plates. 

Draw two 8”x3” rectangles. Take the second one, and draw a line at the 3.5” mark along the 8” side. These will become your bottom plates, the top having a lid, hence the line at the 3.5” mark 

If you have a piece of plywood bigger than 15”x12”, we recommend you use a chop saw to cut off the excess you don’t need. Then, use a bandsaw to cut all of your pieces out. Now, you should have two 4”x8” pieces, two 4”x4” pieces, one 8”x3” piece, one 3.5”x3” piece, and one 4.5”x3” piece. 

On one of the longer side pieces, draw a 0.839”x1.102 box in the corner. Make sure that there is a half a centimeter gap from the bottom (along the 8” side) of the piece of wood to the bottom of the box. 

Use a bandsaw to cut out the box you drew. We recommend you make several cuts down the longer length, and use pliers to break off the pieces of wood that remain. Then use a shiv to file it down and make it smooth. This will be where the rocker switch (NNK JW-M21) for the power will go. 

The 4.5”x3” piece of wood will be the secured top plate, so make a dot at about 1.5” along the 3” side, and about 1” along the 4.5” side. 

Take your marked piece of wood, and set it up to a drill press. Use a 0.5” drill bit, and line the center of it to your mark. Then use the drill press to make a hole for the toggle switch (NNK WT-11) the robot will be flicking. 

Now it’s time for the circuit board stuff! Grab your Arduino Uno, your servo motors, and some male-to-male wires. Wire your Arduino and breadboard as detailed in the above diagram. You may need about 20 Male-Male wires; 7 Red, 9 Black, 1 Green, 1 Yellow, 1 Blue, and 1 Purple.

If you haven’t already, be sure download the Servo library by Michael Margolis for Arduino IDE. Open the attached code in Arduino IDE and tune the timeToArm and timeToLid variables to your machine.

Now that you have that, take the side piece you cut a box out of, the two shorter side pieces (4”x4”),the bottom plate, and the two top plates, and glue them together. For the shorter top plate, you'll need to either make a "hinge" out of tape (which is what we did), or you can buy an actual hinges, about 8mmx10mm. You can use wood glue, hot glue, or super/gorilla glue (preferably one that says it can be used on wood). The first two options are probably your best bet. 

My partner and I wanted to decorate the box, and I very much love mushrooms. So, I added a bunch of stickers to the pieces. This is of course optional, and you can decorate it however you like, if you want to at all.

Attach one gear rack mount vertically to the side of the interior beneath the lid using hot glue. Slide the lid gear rack into the mount and attach the servo to the gear rack to allow it to push the gear rack.

Set aside all remaining 3D Printed Parts and Lego Components. 

Assemble the extending arm as seen above (image of arm assembly here), using the Lego Components to connect them together.

Using the Gear Rack Mounts and Servos remaining to mount the arm to the lid, similarly to the attachment of the Gear Rack for the Lid.