The first motor in the 9V line, the 2838, is relatively
large and has no internal gearing, which results in very
high speed and low torque. It’s ineffective in high-load
applications where it requires substantial gear reduction,
often including one or more worm gears. This motor is also
prone to overheating. The motor has a 1L axle protruding
out of it and connects to the power supply through a 2×5
contact area in the middle of its bottom surface.