Ask the children to bring toys with wheels to school.
Get them to investigate them.
Can they identify the crucial parts:
Wheel.
Axle.
Chassis (Frame).
Body.
Bearing (One part will turn; another part is stationary.The
bearing is where these two parts meet. In some cases the wheel
turns and the axle is stationary. In other cases the wheel and
axle turn together; the frame is stationary).
Study the Inventa Book of Mechanisms: Section 4.
Ask the students to draw their toys.They should mark the names of
the parts on their drawings.
Practice measuring, marking, sawing and deburring1.
Use left-over pieces of wood strip or link strip, dowel or plastic
tube.
Use the video "Make It" sections 6.2 Measuring, 8.1 Using a
Junior Hacksaw and File, 8.2 Cutting Dowel, Rod,Tube and Link
Strip.
Set a target - 6 pieces of wood each 1 cm longer than the next.
1 The process of removing sharp edges and
splinters from material
Making wheel and axles.
Show the students card 3.
Make different types of wheel and axle.
You may want to cut the axles for the students2.
Alternatively use the dowels cut in lesson 2.
Do the mathematics of card 8: Diameters.
Measure the diameter of the wheel.
Mark the wheel.
Mark the start point.
Roll the wheel through one revolution.
Mark the finish point.
Measure the distance between start and finish.
Record the results.
Do the students notice the relationship between the diameter
and the distance between start and finish.They should be able
to deduce the distance is approximately three times the diameter.
Discuss the differences between the various designs.
2 Hint: Use a pencil sharpener to make chamfers
on the end of the dowel
Show how to make a frame.
Show the pupils the card 4.
Encourage children to draw up simple flow charts or step-by-step
plans to enable them to use this format effectively when final
design is drawn up.
Discuss friction with the students.
Use the Video "Make It" Section 10.2 Reaming - Making Holes
Bigger.
Encourage children to draw up simple flow charts or step-by-step
plans "How to Make It:'3 Doing this activity at this stage enables
them to use this format effectively with their final design.
Show students how to use a reamer.
Show them card 5 and discuss how friction plays a part in the way
the wheels are mounted.
Design a buggy3
Students should draw their designs.
They should label the parts.
They should make a list of the materials they need.
Encourage children to draw up simple flow charts or step-by-step
plans "How to Make It".
This should include a list of materials and tools they intend
to use.
3 You might find the Inventa Design Portfolio
Sheets a useful guide for this section
Do the science experiments shown in card 7.
Collect and analyse the data shown in card 8.
Did the finished product match their design?
Why were some models more successful than others?
Why did they change the original design?
What did the children like about their design?
What did they dislike about their design?
What and how would they change it?
3 You might find the Inventa Design Portfolio
Sheets a useful guide for this section
