I think there’s a saying: “If it exists, you can fire it out of a cannon.” No? I may have just made that up. But with enough determination and creativity, there are few objects that can’t, theoretically, be shot out of cannons, just for fun. But if you’re going to build a cannon and shoot something out of it, why not make that something a GoPro camera? That way the projectile can record its own journey, and you can get some cool, if dizzying, footage as evidence of your experiment. This was the thought process of David and Ryan, the duo behind Eclectical Engineering. The two engineers recently started their website as a showcase for their experimental DIY projects, the first of which involved building a pneumatic cannon and firing a GoPro Hero 4 Session Camera from it.
With a budget of $150, David and Ryan had to get creative. They constructed the pneumatic cannon primarily using PVC pipe, along with a blowgun purchased from Amazon and miscellaneous parts including a sprinkler valve, a pressure gauge and a 3D printed trigger guard. Unfortunately, the round barrel of the cannon did not securely hold the small square camera, so the team got the 3D printer out again and constructed an aerodynamic, impact-resistant projectile that would enable the camera to fit snugly in the barrel and still be able to record its flight.
The capsule had to undergo a couple of modifications during the process: the initial design, which utilized flutes to act as airflow straighteners, didn’t exactly straighten the airflow, and the dizzying footage from the first firing attempts illustrated the need for improvements. The second design added spring loaded fins, which provided a much more stabilizing effect.
Using a complex mathematical equation, the team was able to calculate the camera’s trajectory and predict where it would land at the end of its short flight, enabling David to position himself in the ideal spot to catch it as it plummeted towards the ground. They took the cannon and its contents to Crissy Field in northern San Francisco for the official firing, and the cannon and the camera both performed admirably. While it took six attempts for David to catch the projectile in the baseball glove he had brought along, the camera survived intact through every one of its crash landings – a testament to the durability of both the GoPro and the 3D printed capsule.
Want to replicate the experiment yourself? Eclectical Engineering has provided detailed instructions for how to build your own pneumatic cannon and projectile, along with the files needed to 3D print the capsule. With their inaugural endeavor complete, Eclectical Engineering will be following up in a couple weeks with an as yet undisclosed second project, which will then be followed by, the team hopes, many more.
Have an idea for a project you’d like to see brought to life? You can submit it here, and be a part of David and Ryan’s experimentation with “the laws of physics, chemistry, and sanity, all the while pushing our limits with each new device!”
What are your thoughts on this design? Let us know in the 3D Printed GoPro Case forum on 3DPB.com.