Bike Powered Tennis Ball Launcher

I haven’t swung a tennis racket much beyond a couple week unit in PE class 20 years ago, but I love clever inventions that rely on bikes to power them. This Tennis Ball Launcher bike trailer is awesome on numerous levels. You can take it with you to the local tennis courts. You can power it with the bike that brought it. And then you can even aim the launcher by turning your front wheel. Very clever design.