Accession Number:

AD0271402

Title:

RETROFIT OF A KEARNEY AND TRECKER CSM HORIZONTAL BED MILL WITH BENDIX NUMERICAL CONTROLS

Descriptive Note:

Corporate Author:

MCDONNELL AIRCRAFT CORP ST LOUIS MO

Personal Author(s):

Report Date:

1961-11-09

Pagination or Media Count:

1.0

Abstract:

A Kearney and Trecker CSM Horizontal Bed Mill was retrofitted with Bendix Numerical Controls and the performance evaluated in the machining of 5 pieces each of 5 typical aircraft parts. Time required in planning, part programming and computer operations for the retrofit was comparable to that required for a new NC machine. Toolingdesign and fabrication time was also considered comparable. The efficiency of this machine when compared to an NC machine was set-up time, 92.9 and machining time 87.5. Structural design and low spindle speeds of the original machime required was considered equal. Accuracy of the parts was 96.3 as good as those produced by a new machine. Surface finishes were comparable. Cost of retrofitting a second machine of this type was quoted at 92.6 of the cost of an NC machine, comparable in size and cne imposed the limitations which resulted in the lowered efficiency. The average composite time efficiency per piece set-up machine time for the parts produced was 90.8 that of an NC machine. Inspection time required was considered equal. Accuracy of the parts was 96.3 as good as those produced by a new machine. Surface finishes were comparable. Cost of retrofitting a second machine of this type was quoted at 92.6 of the cost of an NC machine, comparable in size and capacity. Procurement time through retrofitting is 43 longer than that required for an NC machine. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE