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Jan 12 th , 2008. Introduction to Lego Robotics. Lesson 4 Gear (part 1) Continue lab work: to build the wheel mechanism. Introduction to Lego Robotics. 2. 8 16 24 40. Spur Gear. Circumference = 2 x Pi x Radius Circumference = Tooth Size x Tooth Count Size x Count = 2 x Pi x Radius
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Introduction to Lego Robotics Jan 12th, 2008 Introduction to Lego Robotics
Lesson 4 Gear (part 1) Continue lab work: to build the wheel mechanism Introduction to Lego Robotics 2
Introduction to Lego Robotics 8 16 24 40 Spur Gear Circumference = 2 x Pi x Radius Circumference = Tooth Size x Tooth Count Size x Count = 2 x Pi x Radius Size = 2 x Pi x Radius / Count (16 teeth) = 2 x Pi x 1 / 16 = Pi / 8 studs = 0.392 studs or 3.14 mm • Gears are normally referred to by their type and the number of teeth. • For example, an 8 tooth spur gear. • Also, a 40 tooth spur gear can be referred to as a 40t gear. • All the different sized spur gears have the same sized teeth. Having the same sized teeth allows the gears to mesh properly. • For gears with number of teeth is 8, its radius (studs) is 0.5. Similarly, (16 teeth, 1 stud radius), ( 24 teeth, 1.5 studs radius), (40 teeth, 2.5 studs radius)
Introduction to Lego Robotics Gear Ratio • Gear Ratio = number of Teeth Output Gear / number of Teeth Input Gear • Gear Ratio = 24 : 8 = 3 : 1 • Torque = Force x Radius • Torque of output Gear = Torque of input Gear * Gear Ratio Output gear, 24 teeth Input gear, 8 teeth 3:1 Gear Ratio