If you’ve been to a Maker Faire you’ve probably come across one or more full-size R2-D2s roaming about or partying with the DJ, chirping and bleeping like the real thing. These robots and other Star Wars “astromech” droids are built by people like myself who are part of the R2 Builders Club. Some of us are crazy for robotics, some just want a screen-accurate replica of their favorite Star Wars droid, and for many of us, it’s both — we love that we can build a real robot that’s an iconic character.
When people encounter R2-D2 they go through stages of surprise, happiness, and curiosity. After a few minutes of ecstatic picture-taking with R2, their curiosity kicks in. “Did you buy it? Did you build it? Is it a kit? How long did it take? Can I build one?”
Yes, you can.
The R2 Builder’s Path
R2-D2 is not for sale, and there is no complete kit available. However, anyone can build an R2-D2. The R2 Builders Club (R2BC) maintains an official set of blueprints, and our members make and share parts. Don’t worry if you’re not a skilled builder. If you don’t have a particular skill, you can learn it. That’s the Maker spirit. Members of the club are always willing to share knowledge and techniques. If we can do it, so can you.
In this article I’ll walk you through a very typical R2-D2 build, so that you can get started building one too. We’ll focus on a simple and relatively affordable 3-leg, radio control setup, with dome lights and Bluetooth audio; you can always add functionality later. You just won’t believe how much people will love your Artoo.
The R2 Builders Club was started by Dave Everett in 1999 as a Yahoo Group to share information for “those interested in building a replica R2.” Today the club has grown to thousands of members around the world, with a Builders Council to moderate the forums and oversee the club’s official R2 specifications and part suppliers. Anyone is welcome to join, it’s free, and it should be the first step on your journey to building your very own droid.
Why Build an R2?
Before you start, let’s discuss a few things to keep you from wasting your money and time and avoid the Dark Side. Why build a full-size R2-D2?
Because you can’t buy one. R2-D2 and its imagery are the property of Lucasfilm and Disney, and to date they have not granted anyone a license to produce and sell full-scale operating replicas. There are sellers on the internet offering a “full size R2” or parts. Stay away. The club forums are filled with threads from people who went this path only to find what they bought was not a quality product and that they wasted their money.
Because you have Lucasfilm’s blessing. From a legal perspective, the R2 Builders Club has a mutual understanding with Lucasfilm and Disney that we don’t exploit our droid building for profit. In turn, with years of good faith under our belts, we are allowed to continue with their blessing. That’s why we don’t sell droids or droid kits to the general public, and we have some rules around it all. The Builders Council is the keeper of the official R2-D2 specifications. Over the years, club members have had the opportunity to measure R2 units from the Lucasfilm archives, and the resulting blueprints have become our official guideline.
Because it’s fun! Anyone can buy something, but figuring out how things work and solving challenges makes it much more interesting. When you build your droid, it truly is yours and is infused with your personality.
How to Read R2 Builders Specs
When you browse the club’s documentation and discussions, you’ll notice three references that are important:
BC Approved stands for Builder Council Approved. Before anyone can offer parts to other members, they have to go through a review process to ensure that their parts are to specification and that they can actually deliver. (BC Continuously Approved just means the supplier doesn’t need approval for each new run of parts.)
CS:L and CS:R stand for Club Specification: Legacy and Club Specification: Revised. CS:L means that parts conform to the Club blueprints created in early 2000. CS:R is a 2014 update based on additional measurements from the Lucasfilm archives and production notes from the various movies. While most people will never spot the difference, these designations are important so that you know whether parts are compatible. For example the body height specification for CS:L is 19.563″, and for CS:R it’s 19.35″. If you go with a CS:R frame, then your skins are different too and you’ll need to use CS:R components such as the “coin returns” and large data port.
Our beginner’s build is CS:L, because I began it 4 years ago; today I’d choose a CS:R build because there are more CS:R parts available.
Before You Build
Building an astromech droid is a big project, but if you break it down into its parts it’s easily achievable. First, ask yourself these questions:
Which droid will you build? R2-D2 is popular but there’s a universe of astromechs to choose from. Do you want a droid that’s screen accurate to a particular movie?
What functionality will you include? Will your droid be static, radio controlled, or have some autonomy? Will its panels open? Perhaps to reveal accessories like a Periscope, Life Form Scanner, or even a lightsaber launcher? Will it be a 2-leg, 3-leg, or, most challenging, a “2-3-2” with a retractable center leg?
What materials will you use? Underlying all these decisions are money and time. The biggest driver of both will be the materials you build with.
When Make: profiled the R2 Builders Club a decade ago (see Volume 02, “R2-DIY”), an all-aluminum droid might cost $20,000 and weigh more than 300lbs. As the club has grown, builders have contributed new “diet” parts that are cheaper, lighter, and stronger. Today an all-aluminum droid can weigh under 200lbs and be completed for about half that cost. Still, it’s the premium option.
Styrene plastic is far more affordable, and it’s lightweight: A styrene droid can weigh well under 100lbs. Shared in the club forums a few years ago, Dave Everett’s styrene plans allow any builder to hand-cut flat styrene stock and build a complete droid with very simple tools, for as little as $500. The tradeoff of course is time. You need a lot of patience cutting each piece. Or spend a little more money and get CNC-cut styrene parts, as we’re doing in this build.
Wood is strong, light, and affordable — it’s generally used for the frame and legs and then covered with styrene. Many builders have used the Senna Wood Frame plans to build their R2.
Choosing a Dome
R4 and R5 series astromechs have a conical head that can be made easily from flat styrene. R2-D2, however, requires a true dome that’s not easy to duplicate. In the past we would have to wait for a “run” of domes to be built by a club supplier, and that wait could be a year or more. Outside of a run, members used BBQ grills, squirrel baffles for bird feeders, and lampshades that closely matched R2’s geometry.
The good news is that today, R2 domes are readily available for club members in aluminum, cast composite materials, or vacuum-formed ABS styrene. For our build we’ll use a laser-cut vacuum-formed ABS styrene dome, but they’re all good choices. I would challenge any non-builder to be able to distinguish the domes once they’re complete.
Just as with aluminum parts, builders have stepped up to provide pre-manufactured components in cast resin, 3D-printed plastics, and CNC-cut styrene. Frank Pirz has engineered a new generation of CNC styrene components that are stronger and lighter by design. These aren’t simply Dave Everett’s plans cut out — that would be a club no-no. Frank took the club’s official R2-D2 blueprints and re-engineered all the styrene components, incorporating the club’s various findings over the years. For our droid, we’re using Frank’s frame, legs, feet, and drive designs. You can buy Frank’s parts pre-cut and ready to go or cut them yourself — just contact Frank through Astromech.net (username: mediaconvert) to get the AutoCAD drawings.
For this build, we’re using Frank’s CNC-cut parts for the entire droid body, with a combination of 3D-printed and cast-resin greebles. Let’s get started!
Now Showing: R2-3D Parts
In recent years the biggest change in building an R2 is the advent of 3D-printed parts. Amongst the builders we have a catalog of approved and verified parts that you can download and print. Before 3D printing, many of the parts on an affordable (i.e., non-aluminum) R2 were made of cast resin. A builder would get permission to copy an aluminum part, cast it in resin, and then supply it to other builders. Resin parts are still available and many builders still use them.
If you think of R2 as a large puzzle with hundreds of pieces, you’ll see why the R2 Builders Club works so hard to protect the integrity of the parts. You can go on eBay or Thingiverse and find “R2 parts” but there’s no guarantee you’ll get what you expect. R2 has hundreds of parts. If you print out a part that someone felt was good enough for their project, but it’s not to club spec, you won’t know it until you’ve wasted your money and your time. When you go to mate that part with other components it might work or it might be off enough that you’ll regret it. Do yourself a favor and follow the advice of all the builders: Stick with approved parts, even 3d-printed parts.
Andrew Radovich, aka Monkeyman, is one of the leading 3D-printed parts designers and suppliers in the club. His own R2 is completed with about 144 individual 3D-printed components. Andrew is printing everything from the Holoprojectors in the dome to the half rounds on R2’s feet. Andrew prints in ABS plastic; he started with a Solidoodle 3 but now has built several printers from scratch just to keep up with all the parts. To see what’s currently available, contact him via the club and his parts thread.
Finishing your 3D-printed parts
Prior to R2, many sci-fi robots had bolts, seams, and other crude embellishments to make them “robotic looking.” R2 is very clean-lined and smooth by contrast. 3D-printed parts can have some texture to them after the print, but you can smooth them easily enough. The acetone technique is not recommended here as you only need to smooth select surfaces. Instead, go over the part with a plastic model filler and then gently sand. Repeat until you’re happy. When you paint, use several coats of a self-filling plastic primer on the 3D-printed parts.