Arc Reactor using Adafruit Neopixels + Rechargeable LiPo

by ChrisBarr, published

Arc Reactor using Adafruit Neopixels + Rechargeable LiPo by ChrisBarr Jul 7, 2014
7 Share
Download All Files

Thing Apps Enabled

Order This Printed View All Apps


Liked By

View All

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag.

Print Thing Tag

Thing Statistics

19606Views 2998Downloads Found in Scans & Replicas


Hey there everyone,

I figured I'd upload this arc reactor I've been working on for a while now. I've printed it off and it all works, so I'm happy to share it around.

There are three pieces - the base (largest), the faceplate and the inner... bit, I guess.

This arc reactor is designed to fit all the components needed to get it lit up and lookin' pretty.

An Adafruit Arduino Gemma will fit right in the very middle. The inner ring on the faceplate is designed to match up with an Adafruit 24 NeoPixel ring, and there's one slot per LED, allowing them to shine through clearly.

There are two external rectangular holes on opposite sides of the base. I designed them one for a micro-USB socket, the other for an on-off slide switch. I ended up using a small SparkFun micro-USB LiPo charger, and the board fits into the base along with everything else.

There's also a circular cut-out on the inside of the base to fit an inductive coil - for inductive charging. I haven't yet tried this out, but the space is there if someone wants to give it a go.

I have the source files made in SolidWorks I can upload - let me know if anyone's interested.


I'll be doing a more detailed Instructable on how to put this thing together at some point, including electronics and such. Until then, this should give you a good overview of what goes where.

Firstly, you'll want to print off the three sections. Black would be a good choice as a base colour, but you'll want to paint this for it to come up looking its best.

There's a little bit of overhang on the base piece, but it should print fine without support material (I didn't have any issues, and my printer struggles with overhangs).

The whole thing is designed to go together using M3 screws and nuts. The inner part pushes into place in the base, the three 'arms' each pressing into a small grove. A single M3 screw then pulls this part tight to the base, with an M3 nut fitting in the indentation on the outside.

The faceplate attaches to the base via five longer M3 screws. Screws longer than ~23mm should do the job, although anything longer than ~28mm you'll need to trim down to get a flush fit.

For physical assembly - that's it.

The outer ring of the reactor is hollow, originally I was planning on running a short length of EL wire through here, but after reconsidering a couple of loops of copper wire look pretty good too.

Speaking of copper wire, for the best look the reactor is designed to have thin copper wire wrapped around every second section of the outer ring - over the solid sections.

This finishes it off quite nicely, but makes it impossible to open the reactor up again without first unwinding the copper - only do this once you're happy with the insides!

Electronics wise, I designed this arc reactor with the following components in mind:

  • AdaFruit Arduino Gemma Microcontroller
  • AdaFruit 24 NeoPixel Ring
  • AdaFruit Single NeoPixel (for centre, sits on top of Gemma)
  • SparkFun LiPo Charger Basic (either mini or micro)
  • Any small LiPo: I used a 400mAh one from SparkFun, anything bigger might be tricky to fit.
  • Small slide switch

If anyone has any questions, feel free to ask via comment - I'm happy to help out.

EDIT: I've written a few details about the wiring for those who were asking:


More from Scans & Replicas

view more

All Apps

Auto-magically prepare your 3D models for 3D printing. A cloud based 3D models Preparing and Healing solution for 3D Printing, MakePrintable provides features for model repairing, wall thickness...

App Info Launch App

Kiri:Moto is an integrated cloud-based slicer and tool-path generator for 3D Printing, CAM / CNC and Laser cutting. *** 3D printing mode provides model slicing and GCode output using built-in...

App Info Launch App
KiriMoto Thing App

With 3D Slash, you can edit 3d models like a stonecutter. A unique interface: as fun as a building game! The perfect tool for non-designers and children to create in 3D.

App Info Launch App

Print through a distributed network of 3D printing enthusiasts from across the US, at a fraction of the cost of the competitors. We want to change the world for the better through technology, an...

App Info Launch App

Quickly Scale, Mirror or Cut your 3D Models

App Info Launch App

Treatstock is an online platform that offers decentralized manufacturing services such as 3D printing and CNC machining for clients all over the world. We offer free and instant access to comparati...

App Info Launch App

3D print your favourite design with NinjaPrototype, a professional 3D manufacture with consistent quality and speed.

App Info Launch App

Do you have a wire schematic of the parts?

Hi! I am just wondering when the Instructable tutorial on the electronics will be available... Your great work is much appreciated keep up the good work!

Would love to see the Instructable, too. My daughter wants to make this for her dad's birthday, but doesn't have a 100% grasp on how to hook it all up exactly.

Apologies for the late reply.

Not quite an instructable yet, but I have a bit more info and a few schematics here: http://chrisbarrbuilds.com/2015/02/3d-printed-arc-reactor/

Hope that helps.

Hi, do you have the electronics component pictures?

I am trying to recreate this and i am a noob. and does not know much about electronics.

Have a look at http://chrisbarrbuilds.com/2015/02/3d-printed-arc-reactor/

No pictures of the components, but a few diagrams showing how everything goes together.

Any chance you could post a schematic for the electronics? How did you step the 3.7v of the LiPo battery up to the 5v minimum of the NeoPixel Ring?

A schematic and a few notes are now available at http://chrisbarrbuilds.com/2015/02/3d-printed-arc-reactor/

Sorry about the wait!

I'll see if I can get a schematic up a little later today.

For the NeoPixels, they should run fine on 3.7v as they use constant-current drivers inside each LED. I had no problems running directly off the Vout (LiPo voltage) and GND connections on the Gemma microcontroller - so basically connected directly to the battery.

Hi Chris, can you please post the solidworks files for this? It has everything I want functionally, but my son's adamant about making the faceplate like in Ironman 2 and I'm trying to oblige him. Thanks, David

Hey there David, not a problem at all. I'm uploading the SolidWorks source files now, and they should be available shortly.

All the best with the project!

Thanks Chris, that's much easier!

Nice, detailed design! Looks great!