Jet Engines Make Roller Skating So Much More Fun

Many people, after finding themselves in quarantine last year with lots of free time and little social activity, decided to pick some new hobbies. Some of those people found quiet indoor activities, like knitting or painting. But others preferred to get out of their musty apartments and into the sun. Roller skating and rollerblading shot up in popularity, because they give people a means to exercise outdoors while social distancing. But roller skates are a slow means of transportation and Ian Charnas wanted a thrill. Taking a page from Wile E. Coyote's playbook, he built a jetpack to increase his skating speed.

The roller skates that Charnas wears in the video are regular ol' skate and there isn't anything about them that would surprise your local roller derby team. The real star of the show here is the jet engine. That is a Swiwin SW300B jet turbine, which retails for around $3,800. Swiwin designed this model for serious RC airplanes and it can reach RPMs of up to 98,000 while producing 30kg (66 pounds) of thrust. The engine weighs 2830g (6.2 pounds), so it is light enough for both a small aircraft and a wearable jet pack.

Before he strapped this jet engine to his back, Charnas had to put it through some tests. To do that, he needed jet fuel. As luck would have it, they sell that fuel at small airports if you can convince the personnel there to let you pump some into a jerry can. With fuel on hand, Charnas welded together a test rig that would let him fire up the engine and test how much thrust it produced in the real world. Those tests were successful, so Charnas then proceeded to the harness design.

Charnas started with a commercial safety harness. That holds a mount for the jet engine that he fabricated from sheet metal cut on a waterjet. The metal frame includes heat shields and enclosures for the electronic components and fuel tank. The jet engine's ECU accepts a servo motor control input so that it will work with a standard RC receiver. Charnas used an Adafruit RadioFruit development board to feed that input. A small OLED screen displays the current status. Charnas holds a throttle control and a dead man's switch for safety. In case something truly horrific happens, his friend has an additional remote kill switch

As you can see in the video, the results are dramatic and exciting. 30kg isn't a huge amount of force and the acceleration isn't extreme. But this jet engine is capable of pushing a skater to a respectable top speed. To put this to the test, Charnas recruited some roller derby enthusiasts. One of them reached a whopping 32mph, which is faster than most people can achieve on roller skates. This is a terrifying project, but it also looks like a lot of fun and we're frankly a bit jealous.