Traditionally, manufacturing internal gears, whether spur gears, which have straight teeth, or helical gears, which have ...

Following is a transcript of the video. Narrator: Lions have them, hippos have them, and even you and I have them: canines, those long, pointy front teeth. They're actually the longest teeth in ...

As one gear turns, the other gear must also turn. Where the gears meet, the teeth must both move in the same direction. In the diagram, the teeth of both gears move upwards. This means that the ...