Design Iteration – How Our Drone Took Shape

David HookCircuit Scribe News

digital rendering of a fully constructed drone prototype

You probably know that we’re busy building DIY drones here at Circuit Scribe. (If you don’t, it’s true! We raised enough from our Kickstarter last summer to be able to make a few hundred.)

We have all the parts and we’re diving into manufacturing them here in Austin, TX as we speak. While we’re putting the first flight together (pun intended), I thought I’d give a tour of how the design evolved since the Kickstarter funded gave us the “go.”

Prototype Land

The whole idea behind our drones is that the kit comes with rotors and the brains-in-a-central-hub (battery, boards, etc.), and the arms are made of cardboard. You draw circuits down each arm from the hub to a given rotor and then back up the arm again to complete the circuit. Draw the circuit, of course, with our conductive ink pen.

The drone kit will come with arms to start with but you can also make your own. Fun stuff!

Early on, we designed a basic drone and tested different shapes of cardboard arms. We 3D printed the hub and experimented from there.

Some early arm prototypes.

Along the way we had to test all the prototypes – sometimes you just have to fly drones around the office for work! And there was much crashing. And occasional puffs of “magic smoke.”

Broken-apart drone with note that it let out blue smoke

Taped to the wall of our prototyping lab: “Let out blue smoke 12-24-17”

We spiraled toward the final design by designing an iteration, testing, repeating. Once we had a design we liked, we had to figure out how we were going to manufacture the drone body and the clips that would hold and power the rotors at the end of the cardboard arms.

The design process wasn’t all about the electronics. A key element was figuring out how to manufacture the plastic hub parts and the holders that grip the motors and clamp them (not too firmly, but not too loose) to the cardboard at the end of the arms.

The Shape Takes Shape

Phase 1 Make a Working Drone

First, we used a 3D printer to make the original prototype hub and rotor-holders design. It was functional, and gave us a good starting point.

We knew we’d be making a smartphone app as the controller, but for the prototyping we used a regular RC transmitter.

An early iteration of the hub and arms design

Phase 2 Make a Sweet Design

Next up, we started iterating on designs we thought were both functional and beautiful. Form meets function. Here’s what the initial Version 2 design looked like.

Phase 3, 4, 5 …

Once we had a basic aesthetic we liked, the game became a back-and-forth of many iterations based upon four interconnected factors:

  • aesthetics
  • how the electronics fit inside
  • how we were going to manufacture the first few hundred
  • how the plastic parts would fit together so that users can charge the battery and replace the arms; and how the plastic would hold any metal clips that would connect to the conductive ink on one side and the electronics on the other

Whew! It was a fun adventure.

Many of the drone design iterations we built along the way.

Making Molds

In the end, we had injection molds made from 3D printed drone models of the drone parts we designed in Autodesk’s Fusion 360¬†software.

One interesting rabbit hole we went down was 3D printing our own injection molds. We did this by using high temp resin with our (amazing) Formlabs Form 2 3D printer. The printer can print plastic that can withstand high enough temperatures to be shot with injection-molding plastic but not melt the mold itself. In the end we had our molds made industrially in order to be able to withstand a higher production run, but the Form 2 was an interesting adventure along the way.

And Finally … A Drone Design

In the end, we landed on a design that met all our requirements: It looks nice; the hub is small and lightweight but big enough to fit the electronics and battery in; it comes apart in the right way for users to be able to charge the battery; and it was suitable for injection molding.

The final DIY drone kit design looks a little something like this:

A late-stage prototype. You can see it has two parts that snap together.

The Final Countdown

What’s next? Now we have all the parts needed to make the drones and we’re beginning to put them together.

We also have a working version of the mobile app that will control flight, and we’re iterating on this as well to make sure it’s user-friendly and has a nice Circuit Scribe look.

We hope you enjoyed our little stroll through drone-land. We’ll keep you updated!