Machine Tool Calibration, Certification, Compensation, services for leadscrew compensation, performance verification, high accuracy machine tools

 


*The C4 Service Plan _ The Four C’s of Machine Tool Performance

Machine Tools today are complicated and expensive investments for any company. When purchasing a new or used machine it is a good idea to have a plan. Your plan should include how you intend to protect your investment in order to obtain positive return on investment. At MD Calibrations we embrace the “Cradle to Grave” philosophy. The overall objective is to maintain maximum performance and minimum downtime. This is achieved through applying C4, “The Four C’s of Machine Tool Performance”.

C4 _ Certification

While all machine tools should be periodically calibrated, not all machine tools require certification. However, machines that utilize on machine gaging as part of their quality process should be calibrated and certified at least annually.

For certification, all of the data acquired during calibration is compiled into a report that provides full documentation in accordance with the selected national or international standard. The standards are very specific as to what needs to be recorded. This includes data such as the “as found” condition, position of the optics and pitch line, expansion coefficient, whether NDE was used, the feed rates applied, dwell time for measurement, type of feedback, position of the environmental sensors, position of axes not under test, offset to tool reference, offset to work piece reference, test starting and ending temperatures, measurement uncertainty, etc. This information is documented in order to obtain repeatability and reproducibility of the measurement results.

Finally a calibration certificate is issued. This is a compilation of the data acquired and analyzed and demonstrates equipment traceability to NIST or other national/international laboratory. Iso-230 recommends the following machine performance data to be presented with a calibration certification;

“A” Bi-directional accuracy of positioning of an axis. This is the range derived from the combination of the bi-directional systematic deviations and the estimator for axis repeatability of bi-directional positioning using a coverage factor of 2.



Where Si = the estimator of the standard uncertainty of the positional deviations obtained by a series of unidirectional approaches at a position.

“A and A” Unidirectional accuracy of position of an axis. This is the range derived from the combination of the unidirectional systemic deviations and the estimator for axis repeatability of unidirectional positioning using a coverage factor of 2.



“E” Bi-directional systematic positional deviation of an axis. This is the difference between the algebraic maximum and minimum of the mean unidirectional positional deviations for both approach directions at any position along or around an axis.



“E and E” Unidirectional systematic positional deviation of an axis. This is the difference between the algebraic maximum and minimum of the mean unidirectional positional deviations for one approach direction (either positive or negative) at any position along or around an axis.



“M” Range of the mean bi-directional positional deviation of an axis. This is the difference between bi-directional algebraic maximum and minimum of the mean bi-directional positional deviations at any position along or around the axis.



“R” Bi-directional repeatability of positioning of an axis. This is the maximum value of the repeatability of any position along or around the axis.

“R and R” Unidirectional repeatability of positioning of an axis. This is the maximum value of the repeatability at any position for one approach direction (either positive or negative) along or around the axis.

“B” Reversal value of an axis. This is the absolute reversal values at all target positions along or around the axis.



“B” Mean reversal value of an axis (Pronounced B Bar). This is the arithmetic mean of the reversal values at all target positions along or around the axis.



A certified machine is a great way to demonstrate to your customers your commitment to product quality. Applying MD Calibrations C4 is a great way to blow away your competition. At MD Calibrations, we are accredited in accordance with recognized International Standard ISO/IEC 17025:2005 General Requirements for the Competence of Testing and Calibration Laboratories. We also meet the requirements of ANSI/NCSL Z540-1 and any additional program requirements in the field of calibration. Our accreditation demonstrates competence for a defined scope and the operation of a laboratory quality management system. We are committed to advancing the field of Machine Tool Metrology. MD Calibrations represents Renishaw’s line of Machine Tool Probes. We can calibrate and certify your machine, retrofit it to one of Renishaw’s Machine Tool Probing Systems, and teach your engineers on the proper method of applying them.

Contact MD Calibrations today to discuss your machine tool calibration needs and to find out how we can meet them.

Copyright 2003-2012 MD Calibrations. All rights reserved
Designed by Image Advantages