There’s no doubt that BB-8, the new droid introduced in J.J. Abrams’ Star Wars: The Force Awakens, is one of the most popular additions to the Star Wars universe. But what makes BB-8 so darned cute? Is it the way it rolls, its unique voice, or the fact that it uses a small blowtorch to give a thumbs up? It’s probably a combination of these things and more, so to get to the robotic heart of the matter, astromech droid-builder Mike Senna let Norman Chan of Tested.com take his precious BB-8 apart.

Senna has been a guest on the show before, and each time they’ve taken a look at a slightly different version of BB-8. Back in October, they looked at (and dismantled) the small-scale Sphero toy to see just how its system of wheels, weights, and magnets gave the tiny droid its signature style of locomotion. It wasn’t long after that when Senna unveiled his 3D-printed, working BB-8 replica at Stan Lee’s Comikaze Expo in 2015. While Senna continues to work on BB-8 3.0 — a mobile version of the droid — to make it more durable for appearances at fan conventions, this current iteration is a pretty fantastic static display piece.

If you’re like me, it was a bit disconcerting to see BB-8 taken apart piece by piece by its creator, but that was a small price to pay for the chance to see inside this magically-moving droid. Rather than focus on the mechanics of BB-8’s roly-poly locomotion, Senna’s build was concerned with troubleshooting the mobility and durability issues when it came to the droid’s head. Powerful servomotors that allowed BB-8’s head to move back and forth had to be fine-tuned in order to keep the connections from twisting themselves into oblivion, and the droid’s “spinal column” was made of a strong length of metal tubing anchored by a coiled spring that acts as a shock absorber to prevent BB-8 from being beheaded by an overzealous fan.

If you’re a fan of Senna’s robot builds, you should check out one of his two websites; if you’re a fan of BB-8 builds in particular, definitely take a look at the BB-8 Builder’s Club to get tips, tricks, and contact information.

Are you into robotics? Do you build your own droids? Let us know in the comments!

Featured Image: Tested, Lucasfilm