new idea The body of this car is made from a strong plastic A 3D printer built up each part of it in layers In approximately 40 hours the 3D printer made a car Some parts such as the motor were made separately Still most of the car was made on the printer This is a new way of thinking about making cars Most cars are made on factory assembly lines Machines and workers make thousands of the same parts Then they combine these parts into identical cars With 3D printing cars are made one at a time A customer could design his or her own car The finished product might look different from any other car As the process gets better printing cars will be faster and cheaper The technology could be used to make many cars at a low cost These cars could even be recycled Each one can be melted down Then that plastic can be used to print a new car Manufacturing objects whether by traditional factories or 3D printers is one of the main jobs of mechanical engineers 6
3D printers build up objects one thin layer at a time Mechanical Engineers at Work The 3D printer is a great example of engineering at work Engineers use science to solve problems They design and build things to make life easier Engineers work in different areas Mechanical engineers design and build machines of all types Some design the engines in cars boats trains and planes Others may work with machinery at power plants or factories Mechanical engineers also develop 7
smaller items They build medical devices and computers They even invent new toys The objects made by mechanical engineers are found around the world They are even found in space Space travel depends on good mechanical engineering In 2012 NASA sent the Curiosity rover to Mars By 2016 the robot was still driving on the planet’s surface More than 7,000 people worked on Curiosity Many of them were mechanical engineers They designed and built it They tested its parts to make sure things Many Branches Engineering has several branches They include civil chemical electrical and mechanical engineering Mechanical engineering is the largest branch It includes many specialties Vehicle engineers design vehicles such as cars and ships Aerospace engineers design aircraft and spacecraft Acoustical engineers work with sound and vibration Thermal engineers study how heat transfers between things They design heating and cooling equipment Manufacturing engineers design and make products These fields are all part of mechanical engineering 8
worked They successfully sent the rover through space to another planet The skills of the mission’s mechanical engineers helped make the rover a success A New Tool for Engineers 3D printers are one of the many tools used by today’s engineers They use 3D printers to build things and test new designs The 3D printer itself was created by an engineer more than 30 years ago A person can use a computer program to IN THE REAL WORLD Working at NASA Many astronauts are also mechanical engineers In the early days of the US space program most astronauts started in the military Over time that changed Franklin Chang-Diaz studied mechanical engineering and physics He became an astronaut in 1980 He had not been in the military Yet Chang-Diaz flew seven missions In one he worked on the International Space Station He made three space walks during that mission After he left NASA he set up his own company He designed technology for space travel Today it is more common for scientists and engineers to become astronauts without doing military service first 9
