Principles of interchangeable manufacturing; a treatise on the basic principles involved in successful interchangeable manufacturing practice, covering design, tolerances, drawings by Buckingham Earle 1887-1978

Author:Buckingham, Earle, 1887-1978
Language: eng
Format: epub, pdf
Tags: Machine-tools, Interchangeable mechanisms
Publisher: New York, The Industrial Press; [etc., etc.]
Published: 1921-03-25T05:00:00+00:00

Machine-hour Rate. Next will be considered the indirect charges that belong to the general productive equipment which, prorated on an hourly basis, will be called the machine-hour rate.

Interest on Investment, Depreciation and Insurance. The first items are the interest on the investment, depreciation, and insurance. These are relatively simple to determine. Their maintenance charges belong here also. When possible, these should be applied to the particular types of machines. The many petty items would be distributed over the entire equipment. Having the machinery, there must be a place to put it. The majority of the factory space is utilized by productive equipment. It would seem, therefore, that all the fixed plant charges would be best distributed here. This could be done proportionately to the average floor space required for operating each type of machine.

Power Charges. The power charges would also be included in the machine-hour rate. One cannot go into the exact distribution of this factor without incurring great expense in power tests — tests that become valueless as the machining cuts vary from light to heavy, short to long. An approximation could be made which would determine the value of this factor close enough for practical purposes. A few power tests could be made to advantage for the purpose of securing data to assist in the proper distribution of all power costs. The cost of belting and lubricating oils, etc., could also be included in the total power charges. Such a plan would insure an equitable and simple method of distributing these.

Non-productive Time of Machines. There is always a certain amount of idle time for any machine, no matter how well the work is planned. The amount of this normal non-productive time varies for different types of machines. For example, an automatic screw machine — as efficient a productive machine as there is — is idle on an average of one hour in five. This idle time is caused by the necessity of adjusting tools, oiling, changing bars, etc. Therefore, the actual productive time of this machine is 80 per cent of its total operating time. In the printing trades, where a complete system of machine-hour costs has

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.