Olympic swimmer Michael Phelps is capable of swimming faster than just about any other human – or at least he was. Phelps’ top speed is about six miles per hour, but engineers Ryan and David of Eclectical Engineering have topped that with a speed of 6.25 miles per hour. However, there’s not likely to be any gold medals in their futures, because I don’t believe the Olympics allow competitors to swim with multiple 3D printed motors strapped to them.
Eclectical Engineering has put 3D printers to plenty of creative uses in the past, including a giant NERF blaster, 3D printed Jello selfies, and a GoPro capsule that was fired out of a cannon. For their latest project, they wanted to see how fast a person could be propelled through the water. Naturally, they turned to Iron Man for inspiration.
“We wanted to see if we could make an ‘Iron Man’-esque suit that could actually propel us through water,” Ryan told 3DPrint.com. “Everyone has dreams where they can fly with just their own body – for us, that dream has been vivid enough that it spurred us to try living it. Unfortunately, flying through the air is pretty expensive and still rather cumbersome, but thanks to the buoyancy of water we can get a similar experience with only a few extra parts. And this was a ton of fun! You can watch your friends ride the struggle boat trying to swim, then at the push of a button you zip right past them!”
They created a suit by rigging up several motors that attach to the arms and legs of the swimmer. The housing for the motors was 3D printed, and without 3D printing, Ryan continued, the motors wouldn’t have worked nearly as well.
“The electronics – motors, controllers, propellers, and batteries – are all commercially available,” he told us. “The harder part was integrating them all together to make a suit that works well. And that’s where 3D printing played a crucial role in this project. We were able to design a mount for the motor cowling that form-fit perfectly to our arms and legs. We were also able to print embedded channels for hook-and-loop tape (velcro) that secured these mounts to our limbs. Those channels are such an irregular shape that they can only be made with additive methods. We also designed recessed holes for hex nuts that locked them in place without compromising the structural integrity of the mount. All of these design features allowed the suit to perform as desired, but were only possible to make if the motor mounts were 3D printed.”
Ryan and David tested the motors in a bathtub, lake and pool, and found that they worked brilliantly. Wearing the motors, David was able to outpace an ordinary swimmer by far, and speed measurements found that a swimmer wearing the suit would even be able to give Michael Phelps a run (swim?) for his money. The 3D printed parts also held up impressively under testing.
“Despite the cowlings only being printed at only 10% infill, they did not crack or even show any signs of wear which was extremely impressive for the technology,” Ryan explained.
The engineers took several measurements to gauge the speed and power of the motor suit, and the results were pretty impressive:
- Thrust per engine: 25.6 lbf
- Top Speed: 6.25 mph / 10.1 kph
- Peak Power: 1.71 hp / 1.27 kW
- Peak Power-to-Weight Ratio: .009 hp/lb / .015 kW/kg (for a 150 lb adult)
- Battery life: 4 hrs of regular use at 1/2 throttle
“From a qualitative stance this was incredibly fun to use. It’s a huge rush being near the surface of the water and going way faster than humans are supposed to swim,” Ryan told us. “It really reminded us of sports cars with low suspension because they really put you next to the road and intensify the feeling of acceleration. Turning was a little cumbersome, however, but that’s because the motors are so powerful and create so much inertia that you need a LOT of strength to move your arms in the direction you want to go. On the bright side – you still get a good workout from swimming…just no cardio.”
Ryan and David aren’t finished with this project yet – as wonderfully as the suit worked, there’s still plenty of room for improvement, Ryan told us.
“The only real downside to the experience is the motors are too powerful for comfort,” he said. “There were a few times during rapid acceleration when the suit felt like it was going to yank our arms out of our sockets, and our arms were sore for about a week afterwards. The best way to address this would be to add strain relief by moving the motor mounts to a stronger part of the body – say the torso for example. We’re also considering making an entirely separate, self-contained vehicle that could give the user a bigger mechanical advantage when trying to make sharp, banked turns. One thing’s for sure – this was too awesome for a one-off!”
Learn more about the project, and see the suit in action, below:
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