Design a motor-driven lift that raises a load to a height within a time: choose a gear ratio against the brief, drive the motor through a driver, and compare the measured result with the prediction.
The winch lesson worked on paper. Does a real motor, real gears and real friction agree with the numbers?
Client: a theatre group that needs a small prop to rise on cue. Context: a model lift on the bench.
Brief: lift a 450 g load 1 m in 15 s or less, stop at the top (a limit switch or a timed stop), and lower it again. The motor turns at 120 rpm and lifts 200 g with no gears; the drum winds 0.1 m a turn. Kit gears (8, 16, 24, 40 teeth), a motor driver, its own battery.
Inquire: Read the brief: who it is for, what it must do (criteria) and the limits (constraints).
Develop: Plan before you build: parts, circuit, code and the tests you will run.
Create: Build it, first in the simulator, then for real if you have the kit. Expect a few tries; that is normal.
Test: Run your tests and record what happened, including what failed.
Evaluate: Judge it against each criterion, and say what you would change.
Make your prediction first. Help opens once you've locked it in.
InquireRead the brief: who it is for, what it must do (criteria) and the limits (constraints).
Inquire: the brief
Sort each line of the brief: a criterion (what it must do, which you can test) or a constraint (a limit you must work within)?
Lifts 450 g by 1 m
Takes 15 s or less
Stops at the top and can lower again
Motor 120 rpm, 200 g with no gears
Gears from the kit: 8, 16, 24, 40
A motor driver and its own battery
DevelopPlan before you build: parts, circuit, code and the tests you will run.
Develop: plan before you build
Try it yourselfYour edits are saved in this browser.
Choose a gear pair that meets the brief, and lift with it.
Use the board. This ticks when you get there.
CreateBuild it, first in the simulator, then for real if you have the kit. Expect a few tries; that is normal.
Create: build it
TestRun your tests and record what happened, including what failed.
Test: run your table
EvaluateJudge it against each criterion, and say what you would change.
Evaluate: against the brief
For teachers
A Years 9–10 design project: a motor-driven lift where the gear ratio is chosen against the brief on the gears board, driven both ways through a motor driver, and the measured lift time compared with the model's prediction. About 250 minutes.
I can compare a model's prediction with a measurement and explain the gap.
Before class
Builds on Mechanisms › Gear up the winch and Power and motors. LEGO Technic or Meccano gears are the quickest real build; printed gears need the CAD pathway. A limit switch (a microswitch on a pin with INPUT_PULLUP) is the tidy stop; a timed stop is fine for a first version.
If you assess with MYP Design, the steps line up with the criteria:
A Inquiring and analysing: the brief, its criteria and constraints, and research into parts (Inquire).
B Developing ideas: a design specification, the circuit and code plan, and the test table written before building (Develop).
C Creating the solution: building it (in the simulator, then for real), following the plan and justifying changes (Create).
D Evaluating: testing against the specification, recording failures, improvements and impact (Test, Evaluate).
Otherwise, use the same four headings as a simple rubric: each step's reflect checks are the evidence list.
Running the lesson
Develop: ask what the model leaves out.
Test: five lifts, mean time, compared with the prediction.
The hard part (on purpose)
The gap between predicted and measured time feels like failure. Make it the point: engineers explain gaps.
When students get stuck
The lift stalls. Ask: What does the model say about margin with friction? Fix: Choose the pair with more strength in hand.
Stretch and support
Stretch: A compound gear train (two pairs) for a heavier load, and the constraint written as an inequality.
Support: The winch worked example beside the board, and a driver wiring diagram.
Where it leads
Other Years 9–10 projects: Two-motor drive base, Automated sorter.
What each step is for
Inquire: the brief: Separating what the design must do (criteria) from the limits it works within (constraints) is the first move of any design brief.
Develop: plan before you build: Choosing the gear pair on the board makes the prediction; the real build then tests the model (no friction) against the world.
Create: build it: Building in the simulator first catches wiring and code slips cheaply; the real build then tests the design against the world.
Test: run your table: Running the test table written in Develop, and recording every result including failures, is the evidence for the evaluation.
Evaluate: against the brief: Judging the design criterion by criterion, with evidence from the tests, is what separates an evaluation from a description.
Now you can
Choose a gear ratio against a brief.
Drive a motor both ways through a driver.
Compare a model's prediction with a measurement and explain the gap.