CASE STUDY:- Eastman Kodak
Stages in the design and production of a special purpose machine, illustrated by the manufacture of an off-axis grinding machine (OAGM) for Eastman Kodak.
Eastman Kodak approached Cranfield Precision for help in manufacturing large aspheric mirrors which, because of their size, needed to be manufactured in several segments. The segments, being off-axis to the mirror, were not rotationally symmetric and therefore had to be produced by a 3 axis profiling technique. As the figure accuracy required was not achievable by any known precision machine, Kodak commissioned Cranfield Precision to carry out a design study, which involved looking at various options of machine configuration and, with the help of an error budget, concept reviews and past experience, choosing a specific design.
The accuracy of specification was demanding, hence the rational development of the machine concept was by a series of iterative steps.
Major Design Features
The initial design layouts show an overall machine design. This shows that the design principles and concepts outlined in the initial stages can be realised in practice.
The major features of the OAGM machine were:
- Bridge assembly.
- Machine structure.
- Reference frame and measuring system.
- Guideway and drive systems.
- Grinding spindle.
- Foundations environment and services.
- Control system.
The OAGM design study report was presented to Eastman Kodak, and Cranfield Precision was given the go ahead to complete the design and then manufacture the machine.
At this stage, each component is drawn and bought out components are specified. Each assembly is detailed and a parts list is created.
Manufacture and Build
Normally, the first part to be assembled is the machine base, and from this the machine can be assembled in logical steps. This stage will also involve checking straightness, orthogonality etc., of the machine.
The commissioning engineer, who will be testing the machine's structure as well as its performance, will then put the machine through its paces.
Once the machine has been commissioned and tested, the customer then witnesses the acceptance procedure, which proves that the machine is performing to its specification, if not better.In Eastman Kodak's case, this stage was successful and the machine was packed and sent to the USA to be installed by a team of Cranfield Precision engineers who also went through the acceptance procedures with the customer for a second time.