The High Throughput Manufacturing Program is sponsored by the Department of Defense. The DOD aim for this program is, in one phrase, to reduce the time that aircraft can spend on the ground awaiting manufacture of spare parts. To realize this aim there must be a reduction in the throughput time for manufacturing engineering tasks. Hence, the "Hithru" program.

Phases I and II of the program are summarized below. Phase III, which commenced in July, 2001, is described on our News page.

Results

These are some of the results on the Hithru Program. Typical results for these types of parts should result in a reduction of at least 50% in throughput time over conventional programming methods.

Program Objectives - Phases I and II

• 50% improvement in NC programming productivity for 5 axis aluminum components.
• Metal removal process optimized for machine/spindle combination.
• Dimensionally correct first article part.
• User enhancement capability to allow edits/additions to libraries of manufacturing methods, machines, tools, materials and machining parameters.

The participants in Hithru Phases I and II were:

• Warner Robins Air Logistics Center (ALC) - depot sponsor, who also supplied the test part model.
• Cincinnati Machine - original project champion, who performed all machine and process characterization, and who carried out program testing and validation using their machine tools.
• Sikorsky Aircraft - provided process best practice data plus real world part design for validation, and carried out further validation requiring measurement.
• National Center for Manufacturing Sciences (NCMS) - program management.
• And ourselves, Technology Answers, providing the Cimskil technology

New participants in Phase III are:

• Cherry Point Naval Air Depot.
• Boeing Defense & Space.

Program Outline

The program worked to provide the following:

• 50% improvement in NC programming productivity for 5-axis aluminum parts.
• Standards for fixtures, tool list and setups.
• Rules-based system that recognizes at least 80% of common 5-axis manufacturing features from STEP solid model of part.
• Automated tool path generator.
• Tool path verification function.
• Interactive process for other features where automation is not yet provided.
• Metal removal process optimized for machine/spindle combination.
• Extensive dynamic testing of machine.
• Spindle/toolholder tap tests to find "sweet spots" that avoid chatter. More details regarding this are given at the foot of this page.
• Shop tests for tool/process technology. Synthesize algorithm from results for: axial and radial depth of cut; spindle rpm; feed rates.
• Cross-validation of the results by more than one program member.

Validation

• Sikorsky provided 29 solid models of real parts for system validation.
• Cincinnati Machine performed validation testing, with Sikorsky conducting CMM checks on finished part(s).
• Results met and in most cases exceeded program objectives.

Optimization of F&S and machining parameter calculations

This is an example of the data that can be maintained and exploited through the Cimskil libraries. For F&S and machining parameter calculations; the program objectives for these and means of attaining them are summarized as:

• Metal removal process optimized for machine/spindle combination
• Extensive dynamic testing of machine.
• Spindle/toolholder tap tests to find "sweet spots" that avoid chatter.
• Shop tests for tool/process technology.
• Synthesize algorithm from results for:
      Axial and radial depth of cut
      Spindle rpm
      Feed rates.

Cincinnati Machine carried out extensive "tap tests" on tool and holder combinations, to derive data as shown in the following representative chart. The optimum data from the results were then used in the program for the target machine, a Cincinnati Machine V5 Lancer 5-axis.

These data were then entered to the Feeds & Speeds Library, and in parallel the tool library was populated with "tap-tested" tools.