Jacko L. Punkin 3D printable Jack-O-Lantern

2024-10-29 | By ARollens

License: Attribution Non-commercial 3D Print Accessories 3D Printer 3D Printing

Its that time of year again that we look to the streets for visiting ghosts, ghouls, and probably goblins. Here is a 3D printable project I designed completely within the walls of DigiKey. Take a look at the project notes below!

Would you like to skip to the files?
Click here to view a TechForum post that includes all of the models in STL format and a parts list.

Click here to view a Digikey Cart with all of the suggested parts.

The Design

This pumpkin is approximately 165mm in both directions making it a nice size for printing on most machines.

Jacko Measurements

The concept is simple. One outer pumpkin shell is printed. I used auto generated supports. Inside of this is the glow in the dark green liner. This has been split into six parts so that it can fit through the hole in the top of the pumpkin.

Jacko Cross Section

The lid consists of four printed parts.

The Stem
The Lid
The Stem Mount
The Component Cover

I designed the stem so that it would print two pieces flat rather than just one requiring a support. It connects using a 15 or 20mm M3 screw.

The component cover screws into the lid using three 15mm M3 screws.

Jacko Lid Spaced Out

The Circuit

I designed this to use two AAA batteries and 6 UV LEDS. I put an 18Ω resistor in line with each LED. You may want to get a few different values to experiment with. Resistors are cheaper than the time it takes to ship. Having some different values could help you find a brightness level that is more desirable to you.

LED Configuration

Click here to use this calculator for yourself

AAA batteries are rated at 1.5V each but usually a fully charged one will come in at around 1.7 or 1.8V. Keeping that in mind I figured with two of them I would be looking at a high voltage of about 3.6V. This is actually the max forward voltage for the LED according to the data sheet. 3V being the actual rated forward Voltage I calculated the resistor value should be about 20Ω.

LED RES Calculator

Before connecting any of these, I put each of the led assemblies in a mounting hole. The wired are meant to slide into the slots to help keep them straight. After that, I simply filled each one with some hot glue.

The connection process is simple. All of the positives need to be hooked together, and all of the Negatives need to be hooked together. Once that is done, then connect to the battery holder with the positive and to the switch with negative. Then attach the switch to the other battery wire.

Component Cover with LEDS

Inserting the green liner

I found this was a bit challenging. The plates wanted slip and slide and I struggled to get them to click. Once I did though, it was a very tight fit and the pieces are not going anywhere. My hope is that it will be easier for you because I modified the model. If I need to put it back it would be great if someone could let me know.

In the end I found that using scotch tape / masking tape to hold the pieces together once I put them in there helped a lot.

Inside layer in pieces Inside the Punkin