No one said the road to The Hackaday Prize would be easy. Many of us have been following [Peter McCloud] as he vies for the Hackaday Prize with Goliath – A Gas Powered Quadcopter. [Peter] literally hit a snag on Monday: his own belts.
Peter had hoped to be performing tied down hover tests by Monday afternoon. Weather and a set of fouled spark plugs conspired against him though. After fighting with engine issues for the better part of a day, [Peter's] 30 horsepower Briggs & Stratton engine finally roared to life. Then all hell broke loose.
[Peter] only let the engine run a couple of seconds before cutting the ignition. In his own words, “Things were running good until the engine was shutoff. At this point one of the belt started losing tension.”
While the tight new engine was quickly losing RPM, the propeller and belt system still had quite a bit of inertia. As the video after the break shows, the belts started flapping and caught on the propeller blades. The front right prop tip caught the double-sided toothed belt, pulling it up and over the propeller. The other end of that same belt lives on the right rear prop. It too caught a propeller blade, snapping the composite blade clean off its hub. The bent steel pulley axles are a testament to the forces at work when things went wrong.
[Peter] isn’t giving up though. He has a plan to add belt guides and a one way bearing to the engine’s crankshaft. The one way bearing will allow the rotor system to overspeed the engine when throttle is reduced. The same bearings are commonly used on R/C helicopters to facilitate autorotation landings.
The project featured in this post is a semifinalist in The Hackaday Prize.