1. Torque

2. Outline fun with seesaws two little people
a big person and a little person
two little people in different spots
equation
example

3. What Will Happen?
Nothing

4. In this case the torques are equal
The Bigger Torque Wins
In this case the torques are equal
so they balance out.

5. What Will Happen?
Why?

6. The Bigger Torque Wins F A force is a push or a pull.
The BIG FORCE creates a bigger torque than the little force. F

7. What Will Happen?
Why?

8. Both forces are the same size.
The Bigger Torque Wins
Both forces are the same size.
The BIG DISTANCE from the pivot point creates a bigger torque than the little distance. F F
(pivot point = fulcrum)

9. What Will Happen?

10. The Bigger Torque will Win
a little force with
a BIG DISTANCE
a BIG FORCE with
a little distance F
Which torque will be bigger?

11. Note: d is measured perpendicular to F
Calculate Torque (T)
T = F d
distance
force F
Note: d is measured perpendicular to F d
pivot point

12. What Will Happen?
F = 200 lb
d = 10
F = 50 lb
d = 70 in

13. Use the Equation F = 200 lb d = 10 in T = 2000 in lb F = 50 lb

14. The Bigger Torque Wins
T = 3500 in lb
T = 2000 in lb

15. Which arm has more torque on it?
10 lbs
Arm 2
F2 =
Arm 1
F1 =
10 lbs d2 d1

16. Which arm has more torque on it?
F1 = F2
d1 > d2
- so -
T1 > T2
10 lbs
Arm 2
F2 =
Arm 1
F1 =
10 lbs d2 d1

17. Motors Provide Torque Torque from the motor makes the wheel spin.
The maximum torque from a Vex motor is 6.5 in*lb.

18. Motor Example T = F d = 0.225 lb x 15 in
d = 15 in
motor
pivot point
F = lb
How much torque would the motor need to supply?
T = F d = lb x 15 in

19. Motor Example
d = 15 in
motor
pivot point
F = lb
How much torque would the motor need to supply?
T = in lb

20. Motor Example
d = 15 in
motor
pivot point
F = lb
The motor has more than enough torque to lift a tube, but it also has to lift the weight of the arm.

21. Can’t loosen a screw?

22. You need more TORQUE!
Push harder (more force) -or- Use the long side of the allen wrench (longer distance)

23. Two ways to hold an Allen wrench
Speed: fast Torque: low
Speed: slow Torque: high

24. Use Torque to Tighten Screws
Or your robot will end up like this!

25. Resources Inventor’s Guide: 3·10
Inventor’s Guide: 3·10