3D Print a Sneaky Pumpkin Safe With Alarm

Happy Fall!

Today, we're going to make a pumpkin decoration to brighten up your home, and store some of your valuables or secret possessions as well!

1. 3D printer - I use an Ender 3
2. Orange and green filament - here and here, respectively
3. Mounting putty, like Blu-Tack
4. 1 Momentary contact switch - here
5. 1 Red LED
6. 9V battery/harness
7. Arduino Nano
8. Soldering iron and equipment
9. Wires

Here's the Tinkercad project - Pumpkin Safe!

If you want to design your own, and put your own touch on it, keep reading! If you just want to print the pumpkin, download the STL file and go to the next step.

Use the STL file from Tinkercad as a base. You can add arms to it, put a face on it, make it red, make it be shorter and squatter, and more! The options are endless!

Above all, all it needs is to have a hole in the middle for valuables and other possessions, and a removable top to hide the important contents of the safe.

I used these settings for my pumpkin and top:

Extruder Temp - First Layer: 216 degrees Celsius

Extruder Temp - Other Layers: 211 degrees Celsius

Bed Temp - All Layers: 45

Infill - 20%

Diameter: 1.75 mm

First Layer Height: 0.2 mm

Other Layers Height: 0.12 mm

Supports: off

If you want to change the bed temp or infill, that's fine. The design will work just as well.

I recommend printing the pumpkin orange, and the top piece green, but you can use green and brown, or orange and brown, or whatever fun color combos you want!

While the pumpkin and top is printing, solder the end row of headers onto the Arduino Nano.

Add very small pieces of putty all around the outside of the pumpkin's hole, so if the top is bumped accidentally, it won't fall off, revealing the contents of the safe. Put the top on and set it in the wild (i.e. your house) for a day, to see if your family/spouse/friends realize it's a fake.

See the indent in the side of the pumpkin? That's for the lever switch. When the switch is on, the light is off, but when the switch is off, the light turns on and flashes!

Start by gluing the lever switch into the indent. Connect two wires to the switch's terminals. Solder one wire to pin 13 and one to 3.3v. Add an LED's anode to pin 10 and the cathode to GND. Connect the red wire to VIN and the black wire to GND on the Nano.

Plug in the Nano and load the code, found here at GitHub. Press the switch. The light should turn off until you release it. That way, when the pumpkin top is on, the LED is off, but when the safe is open, the light should turn on and blink to let you know the safe has been opened.

Time to mount the alarm inside your pumpkin! Stick the Nano and the battery inside of the slots in the side of the pumpkin hole. Glue the LED inside the hole in the pumpkin's top/cover and let dry. Make sure that there's no shorts in the wires.

Your pumpkin safe is done! Good job!

I hope this Instructable helps you keep your valuables, or special possessions, or fun-size candy bars safe and secure, and that you had fun in the process!

Thanks for reading!

Until next time, Happy Fall and Merry Making from g3holliday!