The mechanical crane is a three-dimensional four-bar linkage on a prism shape operated with a set of handles. The main mechanical advantage of this configuration of the four-bar linkage is that with a very little hand movement, it can generate a much larger movement for the arm and hook to grab objects.

Please note this resource was tailored for US schools and may require adjustments to suit UK schools.

🇬🇧 Teacher Notes

Overview and Objectives

Materials

Make a moving joint then connect with straws for a corner of four-bar linkage

Create 2 of the same moving joints then attach to linkage

Make a fourth moving joint then complete linkage

Build 2 beams then click on the free legs of the moving joints

Make a third beam then attach

Create the fourth beam and click to complete the other side of the four-bar linkage

Build 2 bent beams as handles then attach to four-bar linkage

Click connectors on four-bar linkage around the handles

Make a bent beam for the crane's arm

Attach the crane's arm to the four-bar linkage for the top

Make a hook and attach to arm

Make the crane's base

Fit the four-bar linkage to the base

Grab the handles and operate the arm to grab with your mechanical crane!

Build

Challenges

STEAM Classroom

United States

Engineering Design

Forces

Simple Machines

Construct a Mechanical Crane