Levers

Question 1

How is a first class levers set up and is there a mechanical advantage?

Answer 1

Fulcrum is central
Force and load are applied on either end
There’s a mechanical advantage

Question 2

What are some examples of first class levers?

Answer 2

Scissors
Crowbar

Question 3

How is a second class levers set up and is there a mechanical advantage?

Answer 3

Fulcrum on one end
Load in the middle and force on the end
There’s a mechanical advantage

Question 4

What are some examples of second class levers?

Answer 4

Wheelbarrow
Staple gun

Question 5

How is a third class lever set up and is there a mechanical advantage?

Answer 5

Fulcrum on one end
Force in the middle and load on the end
No mechanical advantage but more accuracy and detail in the movement

Question 6

How to calculate mechanical advantage?

Answer 6

MA=Force/Effort

Question 7

How to calculate velocity ratio?

Answer 7

VR=Distance moved by effort/distance moved by load

Question 8

How does a reverse motion linkage work and uses?

Answer 8

Reverses the input to go the opposite way
Used for foldable clothes horses

Question 9

How does a bell crank linkage work and uses?

Answer 9

Changes the direction of force through 90 degrees
Used in a bike brake to make it touch and stop the wheel

Question 10

How does a treadle linkage work and uses?

Answer 10

Converts rotary motion to oscillating
Windscreen wipers in a car

Question 11

How does a parallel motion linkage work and uses?

Answer 11

Makes input and output motion go in the same direction
Toolbox drawers

Question 12

How does a crank and slider linkage work and uses?

Answer 12

Converts rotary motion to reciprocating motion
Piston compressors and pumps

Question 13

Degree of freedom (DOF)

Answer 13

Minimum number of independent variables required to define the position of a rigid body in space, number of a directions a body can move

Question 14

What are all the movements that can be done (DOF)?

Answer 14

Up and down
Right and Left
Back and forward
Roll
Yaw
Pitch

Question 15

What are translation DOF?

Answer 15

Up and down
Forwards and backwards
Left and right

Question 16

What are rotation DOF?

Answer 16

Yaw
Roll
Pitch

Question 17

What is the calculation for DOF?

Answer 17

DOF = 3(N-1)-2Lp-Hp

Question 18

What does N, Lp and Hp stand for in DOF?

Answer 18

N - number of links
Lp - number of joints with 1 DOF
Hp - number of joints with 2 DOF