Grade 5 · Low-Tech Builds · Lesson 96

Turn a Handle, Move a Tab

Make a model crank that changes a slow turning motion into a back-and-forth paper tab.

Time2 × 45 minutesTeamsPairs; alternate builder and testerEquipmentBasic classroom materials; no powered equipment

Your project in view

What you are making

Make a model crank that changes a slow turning motion into a back-and-forth paper tab.

This generated example illustrates one possible finished design—not actual student work. Use the lesson’s sizes, connected parts and safety steps; your colors and creative details can be different.

Generated finished-project example for Turn a Handle, Move a Tab: Make a model crank that changes a slow turning motion into a back-and-forth paper tab.
Turn a Handle, Move a Tab · Generated project example

Student directions · Grade 5

What will you make and do?

Make a model crank that changes a slow turning motion into a back-and-forth paper tab.

Teacher overview: Students will plan the specific object described below, make and test a first version, then use their results to improve it. Read one step together, demonstrate the unfamiliar action, and let students complete that step before moving on.

  1. 1Plan your project

    Sketch a rotating disk, off-center joint and connecting strip leading to a sliding tab.

  2. 2Make the first parts

    Ask the teacher to install the prepared pivot and covered joints. Turn the disk before attaching the tab to check clearance.

  3. 3Put it together

    Fit the tab in a loose straight sleeve and connect it to the strip. Keep all moving parts visible.

  4. 4Test it fairly

    Turn slowly five times and mark the tab’s two end positions. Record jams and travel distance.

  5. 5Improve one part

    Change one guide alignment or connection offset with adult help. Retest five turns.

  6. 6Show and turn in

    Submit the movement diagram, travel distance and cycle notes.

How will you know it works?

  • Tab moves back and forth from turning
  • Joints stay connected during five turns
  • Record the stated test and explain one revision

Before you move on

Explain which measurement, input or design choice you are testing. Predict the result and record what stays the same so your comparison is fair.

Machine cutting, printer setup and electrical power-on require adult approval. A basic-materials model is a valid way to demonstrate the design when equipment is unavailable.

Keep your plan, test notes and before-and-after evidence with the printable design brief below. Use the detailed teacher plan and any coding guide for tool instructions. These steps continue across the lesson’s meetings, not all in one sitting.

For teachers

Engineering standards

This shows how the lesson connects to the national NGSS engineering standards and what student work you can collect.

Assessed

3-5-ETS1-1

Define the need in Make a model crank that changes a slow turning motion into a back-and-forth paper tab. Agree on the two success checks and the listed material limits.

What students show: Two labeled ideas with the target and limits stated.
Practiced

3-5-ETS1-2

Compare the ideas using the project checks: Tab moves back and forth from turning; Joints stay connected during five turns.

What students show: A selected design with a reason connected to a success check.
Assessed

3-5-ETS1-3

Test, change one feature and retest: Turn slowly five times and mark the tab’s two end positions. Record jams and travel distance. Change one guide alignment or connection offset with adult help. Retest five turns.

What students show: Before-and-after results collected under the same conditions.

Materials

  • Cardboard disk and strips
  • teacher-installed covered fasteners
  • guide sleeve
  • ruler
  • Pencil, planning paper and the printable design brief below

Teacher preparation

  1. Gather per-pair materials: Cardboard disk and strips; teacher-installed covered fasteners; guide sleeve; ruler.
  2. Make one rough sample and rehearse the exact test: Turn slowly five times and mark the tab’s two end positions. Record jams and travel distance.
  3. Set the size, load or distance marks mentioned in the steps before class. Demonstrate an ordinary first attempt, not a perfect model to copy.
  4. Prepare any holes, fasteners or difficult cuts for students. Check the stated safety note and clear the testing space.

Step by step

How to teach it

Meeting 1 · 0–8 min

See the job and plan

  1. Introduce the finished object: Make a model crank that changes a slow turning motion into a back-and-forth paper tab.
  2. Sketch a rotating disk, off-center joint and connecting strip leading to a sliding tab.
  3. Students say what would count as a successful result.
Meeting 1 · 8–18 min

Model the unfamiliar action

  1. Demonstrate slowly: Ask the teacher to install the prepared pivot and covered joints. Turn the disk before attaching the tab to check clearance.
  2. Pause so partners can repeat the action; provide prepared parts if cutting or folding blocks progress.
Meeting 1 · 18–35 min

Build the first version

  1. Fit the tab in a loose straight sleeve and connect it to the strip. Keep all moving parts visible.
  2. Partners swap builder and checker roles halfway through. Check the working part before decorating.
Meeting 1 · 35–45 min

Try once and save

  1. Run one trial of the stated test to locate an obvious problem. Do not count a changed procedure as a fair comparison.
  2. Label and store the model; sketch its current shape and clear the work area.
Meeting 2 · 0–8 min

Predict and set up

  1. Revisit the two success checks. Agree on identical starting conditions and prepare a before/after results table.
Meeting 2 · 8–23 min

Collect evidence

  1. Turn slowly five times and mark the tab’s two end positions. Record jams and travel distance.
  2. One student operates while the other records. Swap for a later trial while noting a change of operator if it affects the result.
Meeting 2 · 23–35 min

Change one thing

  1. Change one guide alignment or connection offset with adult help. Retest five turns.
  2. Keep the original results rather than replacing them with only the best attempt.
Meeting 2 · 35–45 min

Explain and clean up

  1. Submit the movement diagram, travel distance and cycle notes.
  2. Collect the brief and results; separate reusable materials and clean the test area.

Assessment

  • Tab moves back and forth from turning
  • Joints stay connected during five turns
  • Student demonstrates the actual task: Turn slowly five times and mark the tab’s two end positions. Record jams and travel distance.
  • Record includes failures as well as successes.
  • Student identifies one changed feature and uses the retest to explain the result.

Supports & extensions

  • Provide a worked first joint or sample; have students record dimensions and explain one comparison limitation.
  • Start with the smallest working version of turn a handle, move a tab before decoration.
  • Extension after success: choose one more value for the same tested feature, predict its effect and repeat turn slowly five times and mark the tab’s two end positions.

Safety & responsible use

  • Teacher checks materials and test conditions before use. Use classroom scissors; adults prepare difficult cuts, holes and fasteners.
  • No powered tools, coding, hot glue or electrical circuits are required. Keep moving objects contained and test loads light.
  • Adults make holes and fit fasteners; cover sharp ends and keep hands out of joints.

No-machine alternative

Use prepared paper parts, larger pieces or an adult-assisted version of the same build. Keep the functional task: Make a model crank that changes a slow turning motion into a back-and-forth paper tab. If physical testing is not possible, label sketches as predictions rather than measured results.

Printable student design brief

The challenge

Make a model crank that changes a slow turning motion into a back-and-forth paper tab.

Success criteria

  • Tab moves back and forth from turning
  • Joints stay connected during five turns
  • Record the stated test and explain one revision

Constraints

  • Use only the listed teacher-approved materials
  • Stay within the teacher-set size, load and test-space limits
  • Two 45-minute meetings; keep the first version simple

Engineer’s notes

Who uses this object, and what should it do?
Draw two possible designs. Label the working parts and circle your choice.
Which size, fold, gap or position must you measure or mark?
Before testing, predict what will happen: Turn slowly five times and mark the tab’s two end positions. Record jams and travel distance.
Record each trial: condition / expected result / actual result.
Draw the ONE change you made. What stayed the same?
Record the retest. Did the change help, not help, or leave the result uncertain?
Show and explain: one result that supports your conclusion.
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