Made in China: Chinese Make 'Homemade' Gears from Recycled Materials. Zhang Wuyi, a local farmer who is interested in scientific inventions, has successfully tested his self-made miniature submarine "Shuguang Hao." A 3.6 m (12 feet) long, 1.8 m (6 feet) high, and with a maximum diving depth of 20 m (65 feet), Wuyi's submarine can travel at a speed of 20 km per hour for 10 hours underwater and is shaped as a dolphin. "I hope to sell my submarine as a civil product at the price of about 100,000 yuan ($15,670) after safety tests, and a merchant has decided to order one in this month", he told Reuters on Monday.Wuyi is not the only invention-enthusiast in China. Many Chinese have even made their own helicopter, cannon, robot and more, using recycled materials.