Guide

Mechanisms: Lifting Mechanisms (Grades 4-8)
Before discussing Lifting Mechanisms, it’s important to know what a Degree of Freedom is. A
Degree of Freedom refers to an object’s ability to move in a single independent direction of motion.
To be able to move in many directions means something has many Degrees of Freedom. Moving up
and down is one degree of freedom, moving right and left is another; something that can move up/
down and left/right has TWO Degrees of Freedom.
A Lifting Mechanism is any mechanism designed to move to perform tasks and/or lift objects. With
that understood, let’s look at Lifting Mechanism types. In competition robotics, there are three basic
types of Lifting Mechanisms: Rotating Joints, Elevators,
and Linkages.
Rotating Joints
The most frequently used lifting mechanism in mobile and
competition robotics is a Rotating Joint. Rotating Joints
are the simplest Lifting Mechanisms to design and build. In
VEX IQ, using a shaft and gears quickly creates an arm that
will rotate and lift. This type of Lifting Mechanism moves
on an arc, changing both the distance any manipulated
objects are from a robot base, and changing the orientation
of those objects (relative to their environment) on the
way up.
Elevators
Another lifting mechanism used in mobile and competition
robotics is an Elevator. While not as common as the
Rotating Joint, the Elevator uses linear (straight line)
motion to lift straight up. In VEX IQ, one way that elevators
can be built is with Rack Gears and Linear Sliders,
both sold as part of the Gear Kit. This type of Lifting
Mechanism moves straight up and down, keeping the
distance between any manipulated objects and the
robot base, as well as the orientation of those objects,
consistent on the way up.
Linkages
Linkages can also be used to build Lifting Mechanisms.
Linkages consist of a series of rigid bodies called links,
connected together by freely rotating joints. Linkages
convert an input motion into a dierent type of output
motion and can be very consistent. For example the
input motion could be a Rotating Joint, but the Linkage
could produce Elevator-like output motion. In VEX IQ,
combinations of dierent-sized beams, shafts, and/or
connector pins can be used to construct a Linkage.
G.6