The "Tool Change Report" is a very specialised analysis.
Background information: Many production machines have tools in use that need to be changed gradually. (e.g. turning chisels that wear out). After a tool change, you don't want to "set up" the machine again every time. So these high-precision tools are set up in an upstream process.
The idea behind a tool change study is to find out what impact a physical tool change on a machine could have on the location of the process and if further adjustments are needed after a tool change.
The author himself remembers this from 25 years ago. Using a magnifying glass with crosshairs, the milling cutters were inspected for the new tool and the deviations in diameter were documented and entered into the PLC of the production machine after the tool change.
But how good is a process after a tool was changed / replaced? This is what the "tool change report" attempts to find out.
The first part of the process is as follows:
- X components are produced and measured (approx. 50 pieces) for the machine capability study
- Requirements of the machine capability study have to be met before moving on to a "Tool Change Study"!
- The measured values are collected in a separate DFQ file.
- This DFQ file is saved as a new DFQ using the "File - File Save... - Save for tool change" function. Make sure to give this file a NEW NAME, for example by adding "saved for Tool change" at the end of the file name .
This new dfq-file does not have any values anymore. But for every characteristic the average of the values have been saved in K2100, the “Target-value”
A physical tool change is now carried out on the machine. If no new tool is available during the machine run-off of a new machine, the tool change is to be simulated by removing the tool and placing it back into the machine.
X components are produced and measured (approx. 5 to 10 pieces) after the tool change.
- The measured values are collected in a separate DFQ file.
This both dfq – files are now merged with the Menu-Option “File – File... - Merge Files”. As "Master" file, select the header file that was previously "saved for Tool change" , as second file under "Value files lising" select the file *.dfq file with the new measurements from after the tool was physically changed.
With this new dataset, the Tool Change report can be viewed to analyse the difference in averages before and after the tool change.
The requirements for meeting the Tool Change report requirements are that the average after the tool change not vary by more than 25% of the tolerance from the average before the tool change if the new average moved towards one of the tolerance limits and not away from it. In addition, the range of the data from after the tool change may not be larger than 25% of the tolerance.
The requirements cannot be changed. They are fixed inside of the application.