when you start learning modelling and designing this question comes first in mind ... Size of any component or product depends on
- what is your propose to design.
- what is your space constraints(area available for your product)
- minimum size or optimized size for function without compromising the purpose and performance of that part
Design size is calculated by analysis of product for fulfillment of the purpose
for example if u want to design cooler ..
cooler size will be driven by
1. room volume to be cooled
2.how many heat source and rate of heat entering to the room
3.environment conditions of area and so many factores
my formula is ..design big ...then reduce the size to minimum after incorporating the all parts of any machine or product..my answer may be not up to the mark ..
