Introduction: 3D Printed BTS Light Stick With an Mp3 Player

For our SIDE project in Ms. Berbawy's Principles of Engineering class, we recreated a BTS light stick, also known as an ARMY bomb. Unlike the original light stick, our light stick could not change colors or sync up with Bluetooth. To make our project special, we decided to have our light stick play music.

The original light sticks cost at least $50 prior to shipping from South Korea, so making a light stick of our own was an affordable and innovative solution. This project is important to us because BTS isn't just a typical kpop group; BTS is an inspiration to youth all around the world, spreading their Love Myself and #ENDviolence campaign as ambassadors for UNICEF.

We had access to many Maker resources in Ms. Berbawy's classroom and were interested in learning how to use them to replicate the expensive BTS light sticks that many fans wield during concerts. Our process consisted of several iterations of trial and error. We began by going off of rough measurements of the light stick we found on the internet. Throughout this project, we developed better CAD skills, understanding of circuits, and soldering skills. We used Autodesk Inventor for the design and both a Lulzbot Mini and Lulzbot TAZ 6 to create our 3D prints.

Step 1: Materials and Tools Used

There were 2 parts to the project the mp3 player and the 3d printed light stick.

What we used for 3d printed parts:

  • Autodesk Inventor Professional 2018
  • Clear and Black 3D Printer Filament
  • Lulzbot Mini/TAZ 6
  • Gorilla Super Glue Gel

What we used for mp3 player:

Other useful materials include:

  • Dremel tool
  • Safety glasses(while soldering!)

Step 2: Reaserch and Resources

When researching in preparation for this project, we found many images of the light stick but little to no actual measurements. We decided to take the measurements of an older version of the light stick from 2015.

We looked on Instructables and Youtube to learn how to create an mp3 player and followed the instructions posted by HardiqV and KJDOT. To understand how the string lights work, we referenced a Youtube video by bigclivedotcom.

Step 3: 3D Print Designs: Globe

This step has the cad file and the printer settings to print the globe.

Step 4: 3D Print Designs: Body/Stick

This step has the cad file and the printer settings to print the body/stick part. If needed, use a Dremel tool to sand away at the slot where the switch is supposed to fit in.

Step 5: 3D Print Designs: Smaller Pieces

The file titled "bts_slideincap[1]" is the piece meant to fit on the bottom of the body piece, while the other 2 files go on top of the globe for purely aesthetic reasons.

Step 6: Preparing the Lights

For this specific set of string lights, we need to strip them first because they're coated. After that, separate the 3 wires and find the positive and negative wires by placing 2 wire at the end of a battery. If that doesn't work, use a different combination of wires till it works. After finding the positive and negative make the wires and put it aside for the moment.

Step 7: Circuit Diagram

Above is the schematic diagram drawn out. We soldered all the parts together as shown to create the circuit.

This is a parallel circuit so that the switch can control both the mp3 player and the string lights.

Step 8: Songs

After downloading your favorite BTS bops, upload it onto a micro USB card and insert it into the micro sd slot of the mp3 decoder board.

Step 9: Assembly Time

The video of the final product and assembly file are attached in this step.

After all the 3D parts are printed and the mp3 player is made, carefully place the circuit into the body of the light stick and make sure the switch is secure in its slot. Feed the string lights into the globe which will then be superglued on top of the large end of the body/stick. The only opening left would be at the bottom of the stick, where the cap is secure yet able to slide on and off as you please.

The light stick is now complete!

Step 10: Credits

A big thank you to our dear teacher, Ms. Berbawy, for providing us our resources and her patience. Another thank you goes out to BTS and their fanbase, ARMY, for giving us inspiration.

And last, but not least, thank you for checking out our project!

Team Members: Akanksha Srivastava and Minh-Ha Nghiem