Page 77 - Toucpad robotics C11

2. Design a Planar or Spatial Mechanism in Tinkercad

Task: Using Tinkercad (free online tool), create a simple 2D planar mechanism (like a scissor or piston
l
system) and a simple 3D spatial mechanism (like a robotic arm with 3 joints). Try moving parts to simulate
their motion.
Output: Screenshots or a short video showing your models, along with a short note explaining how degrees
l
of freedom were applied in your design.
Learning Outcome: Apply theoretical knowledge of planar vs. spatial mechanisms in a virtual lab environment.
l
3. Compare Materials and Wheels for Robots
Task: Research four materials (MDF, Acrylic, Aluminium, Steel) and two wheel types (Mecanum, Omni).
l
Create a table comparing their strength, cost, weight, and best application. For example: MDF (low-cost
prototypes), Aluminium (drones, robotic arms), Mecanum wheels (tight-space navigation).
Output: A comparative chart with pros, cons, and a suggested “best use case” for each material and
l
wheel type.
Learning Outcome: Develop decision-making skills in mechanical design—understanding why
l
engineers choose specific materials and mobility systems for different robots.

AT A GLANCE

A Frame is a coordinate system (with an origin and a set of three perpendicular axes, typically labelled X, Y,
and Z) that provides a reference for defining the position and orientation of objects within that system.
In robotics, we primarily deal with two types of reference frames: Fixed Frames and Moving Frames.
The term Degrees of Freedom refers to the number of independent parameters that define the configuration
of a system.

A Planar Mechanism is a mechanical system where all the links and joints move within a single, two-
dimensional plane.

A Spatial Mechanism is a mechanical system where the motion of its links and joints is not confined to a
single plane.

A Planar Open-Chain Mechanism is a series of rigid links connected by joints, where the entire structure is
confined to moving within a single, two-dimensional plane.
Different Components of a Robot include Frames, Materials, and Wheel Types.
A Coordinate System is a system that uses one or more numbers, or coordinates, to uniquely determine the
position of a point or other geometric element on a manifold, such as Euclidean space.
Resolution refers to the smallest incremental movement that a robot can detect or achieve.
Accuracy is the ability of a robot to position its end-effector precisely at a desired location in three-dimensional
space.
Repeatability is a robot’s ability to return to a specific position under identical conditions repeatedly.

75
Mechanical System