Specifications

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CHAPTER 4
Construction and Design
4.1 Initial Design
Several ideas were analysed before the initial prototype was built. The mechanical
structure of the robot was a major consideration. Wheels versus tracks, mechanical
steering versus dual motor drive and other considerations along with shape and
dimensions were the chief factors.
Initial analysis of these ideas provided a dual motor, two track setup with a wide wheel -
base for stability. This design is shown in figure 4.1 below.
Figure 4.1: Initial Chassis Prototype
This design seemed very practical for this application due to its small centralised
arrangement, its excellent turning circle and ability to manoeuvre. The problem
occurred however when the drive motor could not gain sufficient traction to the rubber
track. Several different ‘drive hubs’ were implemented to attempt to overcome this
problem however the rubber tracks were too flexible with a very small coefficient of
friction. The setup required to make this arrangement successfully work far out-
weighed the practicality of the design.