I've had several classes of middle school and high school students make electric motors like those described in Get Your Motors Running from TeachEngineering. This activity provides just about the perfect level of difficulty for the great majority of students. Activities that are too difficult can be discouraging; while those that are too easy make very little impression. This activity requires students to make a coil that is well balanced, and to adjust the paper clips so that the motor spins freely, and makes good electrical contact. It requires quite a bit of fiddling, but when they get it working, the students jump out of their seats! When presented as part of a sequence of related activities, including electromagnets, these simple motors help students understand the technology of motors and generators, and also the science of electric and magnetic fields, as required by the NGSS.