Precision machines are necessary to manufacture
parts and subassemblies that require tight tolerances.
During the design of precision machines, like any design,
it is critical that the best concept is chosen in the early
stages of the design process because 80% of the final cost
and quality of a product are designed in at this phase.
In addition, changes and optimization late in the design
process have limited impact on cost and quality. Typically,
during the design of precision machines, engineers and
skilled machinists develop several machine concepts and
down select based on heuristics and past design experience
rather than quantitative measures. This paper describes
a computation tool, Precision Machine Design Assistant
(PMDA), which automates basic machine error simulation
and concept evaluation. The tool uses a combination of
machine error motion modelling and constraint-based design
methods. By combining these methods in a computational
environment, multiple machine concepts may be rapidly modeled,
analyzed, and compared. The goal of the program is to assist
the designer in the selection of a superior concept for
detail design. The PMDA methods and implementation are
demonstrated in an example.