Mini Grabber

The Mini Grabber lesson takes students back to their childhood when they may have played with scissor action toys or grabbers. Students are reminded of the fun that can be had with these simple mechanisms as well as the physics and mathematics behind their operation. Students are challenged to follow an iterative prototyping and shortlisting process to create a proposed final design. They can test their final design using a cardboard prototyping tool before committing to model their design in 3D. Once the model is created, the design can be 3D printed and fitted to a shared scissor mechanism for testing. 
ScienceComputingDesign and TechnologyMathematics
Years | Grades
9th Grade | 13-14 years10th Grade | 14-15 years11th Grade | 15-16 years
Lesson 1: 90 minutes Print time: ~ 40 minutes Lesson 2: 90 minutes

Mini grabber trailer
Play 0:37


  • Design a prototype attachment to pick up an object of the individual’s/teacher’s choice
  • Follow an iterative prototyping process to narrow designs down to one final design
  • Use a prototyping template to create a cardboard prototype of the final design for testing
  • 3D model the chosen final design
  • 3D print and test the final design

Tools and equipment

  • BE3D eDee 3D printer with filament
  • Computer, mouse and access to CAD software and the school’s network
  • 1+ Mini Grabber assembly (printed in advance)
  • 14 Chicago screws, 5 mm x 15 mm (per Mini Grabber assembly)
  • 1 prototyping template resource sheet per group
  • 2 Phillips/Pozi/Crosshead screwdrivers and snips
  • Cardboard
  • Small objects to be “grabbed”  (for example: eraser, glue stick, pencil sharpener)
  • Calipers
  • Scissors
  • Pen/pencil and paper

Skill requirements

To participate in the lesson, students should be able to:
  • Carry out simple mathematical functions and measurements
  • Use TinkerCAD, Fusion 360 or similar CAD software at a beginner/intermediate level
  • Be comfortable using DeeControl software including adjusting print settings
  • Use the BE3D eDee printer

Mini Grabber walkthrough
Locked 4:46

3D models overview

  • Total print time 5 hours
  • Total filament 10.5 m
  • Additional non-printable components
  • Printed all at once
Mini Grabber End Effector Connector
  • 20 minutes
  • 0.4 m
End effector V1
  • 30 minutes
  • 0.5 m
End effector V3
  • 30 minutes
  • 0.5 m
End effector V4
  • 30 minutes
  • 0.5 m
End effector V010
  • 30 minutes
  • 0.5 m
Mini Grabber Handle
  • 30 minutes
  • 1 m
Mini Grabber link
  • 20 minutes
  • 0.4 m
Mini Grabber Pin
  • 10 minutes
  • 0.1 m
Optional spacer
  • 10 minutes
  • 0.1 m
Note: Values are calculated for one set of models.

Lesson resources

  • Lesson plan
  • Example Mini Grabber model
  • Worksheet
  • Walkthrough
  • Walkthrough Video
  • Presentation
  • 3D models
  • 3D print instructions
  • Curriculum Alignment: ISTE standard compliant
  • Prototype template sheet