Neopixel Jack O’Lantern

This model is the result of the second collaboration with ItsMrJP. Also check out our first design: the FiberBalloon.

The pumpkin was designed from scratch with 9 integrated fiber channels for the sideglow filament. Optional you can also use just 2.85 3D-printing filament like I did in my vase project. But you have to bend it before inserting it into the channels. There is a cylindric hole inside the pumpkin to store batteries.

Only basic soldering skills are required.

A short video is available on Twitter.

Partlist:

• 9 LEDs from a 60 LED/m WS2812B LED strip (Adafruit, Pimoroni, Aliexpress)
• 2m of 3mm (or 0.12inch) side glow optic fiber (Amazon, Aliexpress)
• Raspberry Pi Pico
• some wires

Model consists of 6 parts. Eyes and mouth are optional, you can also just paint them black. 

Printing instructions:

The pumpkin is the most tricky part to print. To reduce filament weight, there is a 3mf file provided with 10% lightning infill and an additional modifier in the middle top region to support the upper part of the pumpkin. The model was printed with a 0.6 nozzle to fasten up the print. 

The bottom and the face need support to the build plate. This was done with paint-on support to remove the central hole at the bottom, which just can be bridged.

This is a picture of the print process, where you can see the growing lightning infill structure:

Assembly:

Cut off a segment with 9 LEDs from the LED strip:

Wrap it around the base segment with the double sided tape, so the stripe starts at the slot for the wires, also you can snap in the Raspberry Pi Pico at the bottom:

Now finally wire the stripe to the Pi with the following connections:

PI →  LED

VBUS → 5V

GND → GND

GP22 → DIN (you can use any other GPIO also)

Should now look like this:

Now the optical fiber can be inserted in the channels. If you want to insert/paint the face, do it before inserting the fiber. Start in the middle and slide in the fiber to the top. Slightly push it into the channel. Then repeat this at the bottom by inserting the fiber in the hole, push it in and after checking the fit on bottom and top, cut off the the exceeding part.

Finally slightly push in the base in the pumpkin. There are slots for alignment.

To program the Pi pico, just follow this instructions.

Final result: