Sorry Charlie, but I think this one is actually the Great Pumpkin. The flamethrowing Jack O’ Latern by Randy Sarafan couldn’t be more awesome, could it? I so want to use this for a Headless Horseman costume!
Check the bottom of the post for an animated movie of the Jack O’ Lantern in action. Keep in mind, these instructions have been abbreviated so make sure to check out Instructables for the full set. You can see more of his awesome projects here.
- A really big pumpkin, around 18″ in diameter
- An assortment of serrated cutting knives
- A marker
- Paper and pencil
- A spoon
- Other scraping implements. I found a chisel worked very well.
- Door lock actuator
- Arduino/Xbee transmitter and receiver
- Small can of WD-40
- 12″ x 12″ x 1/8″ sheet of black acrylic
- SPST 5V relay
- 5″ x 2.5″ x 2″ project box.
- SPST momentary pushbutton switch
- 10K resistor
- (x2) 9V battery snap
- (x2) M-type plug adapters
- Misc. long zip ties
- 16″ x 2″ x 1/4″ aluminum extrusion
- 3-1/2″ x 1/4 bolts
- (x6) 1/4 nuts
- Tea light
1. Carve and gut the pumpkin. You’ll want to start by hand but eventually use a metal spoon to get it all. Remember, save the seeds and toast them. They are way yummy!
2. Trace out the face on paper and apply it to the pumpkin. The scarier the better, remember, this thing is going to be breathing fire. It shouldn’t look like a Care Bear.
3. Stack the motor mounts and align it. Zip tie it to the aluminum bracket. Then add in the WD-40. You can see full instructions on this here.
4. Place the bottom of the candle holder (the side without the large hole) onto the bolts. Then place the top candle holder bracket. See here.
5. Solder the 9V battery snap to the M-type plug such that the red wire is connected to the tip and the black wire is connected to the barrel.
7. Install the antenna into the side of the enclosure opposite the switch. Be careful not to break the wire connecting the antenna to the XBee.
8. Solder a wire to one leg of a 10K resistor. Solder the opposite end of this wire to one of the switch terminals. Plug in the side of the resistor with the wire soldered to it into pin 2 of the Arduino. Connect the other end of the resistor to ground. Solder a wire to the other terminal on the switch and connect this wire with 5V on the Arduino board. Lastly, plug your 9V battery connector into the power socket on the Arduino board.
9. Connect one of the relay’s coils to ground on the Arduino board and the other to pin 3. Attach 9V to one of the relay’s load pins and a long red wire to the other.
10. Wire the motor to the relay wires such that when the relay closes, the motor’s actuator pushes down. In this case, red went to blue and black to green. It may be different for another motor.
11. Wire it all up!