1. Forging new generations of engineers
Simple Machines

2. Levers
Each lever is classified by the location of the loads in relationship to the fulcrum

3. 1st Class Lever
Fulcrum is located between the effort and the resistance force
Effort and resistance forces are applied to the lever arm in the same direction

4. Only class of lever that could have a MA greater than or less than 1
Effort
Resistance
Effort
Resistance
MA >1
Resistance
Effort
MA <1

5. Class 1 Lever

6. 2nd Class Lever Fulcrum is located at one end of the lever
Resistance force is located between the fulcrum and the effort force
Resistance force and effort force are in opposing directions

7. Always has a mechanical advantage >1
Resistance
Effort

8. Class 2 Lever

9. 3rd Class Lever Fulcrum is located at one end of the lever
Effort force is located between the fulcrum and the resistance
Resistance force and effort force are in opposing direction

10. Always has a mechanical advantage < 1
Resistance
Effort

11. Class 3 Lever

12. Wheel & Axle
A wheel is a lever arm that is fixed to a shaft, which is called an axle.
The wheel and axle move together as a simple lever to lift or to move an item by rolling.
It is important to know within the wheel and axle system which is applying the effort and resistance force – the wheel or the axle.

13. Calculations Wheel & Axle Circumference = 2 π r or π d Ǿ20 in. Ǿ6 in.
200lb
70lb
Circumference = 2 π r or π d

14. Ǿ6 in.
Ø 20 in.
200lb
AMA=
70lb

15. Inclined Plane Calculations
15 ft
4 ft

16. Inclined Plane
A flat surface set at an angle or incline with no moving parts
Able to lift objects by pushing or pulling the load

17. Pulley IMA- Count Strands Pulling down (don’t count)
800 lb
230 lb
Pulley
IMA- Count Strands
Pulling down (don’t count)
Pulling up (count)
AMA =
800 lb

18. Pulley
A pulley is a lever consisting of a wheel with a groove in its rim which is used to change the direction and magnitude of a force exerted by a rope or cable.

19. Wedge Functions as a moving inclined plane
Tapers to a thin edge and is used for splitting, raising heavy bodies, or for tightening by being driven into something

20. Wedge Calculations
T 3 ft
L ft

21. Screw
Two Components
An inclined plane wrapped around a cylinder, forming the path and pitch
A wheel and axle used to create rotary motion
Properties
Change rotary motion into linear motion
Used as a threaded fastener
Large MA
Large amount of friction loss

22. Diameter
Screw
Effort Arm Distance – If using a wrench, effort arm distance would be the length of the wrench
Pitch
Distance between threads and linear distance traveled by 1 rotation of the screw