This machine inspects the quality of an assembly consisting of a plastic frame and a long strand of very thin wire that has been placed in specific slots and tensioned just the right amount with a Fanuc robot. The final assembly resembles a tiny guitar with four strings on one side and four strings on the other side. This guitar wouldn't play any interesting songs because all the wires are "tuned" to the same frequency. The wires are only a few thousands of an inch thick and they have a very thin glass coating that acts like an insulator. The operation of the machine can be seen in this video, Precision Part Inspection Machine and the corresponding graphical user interface can be viewed here, Precision Part Inspection GUI.
The key elements of the machine are the Keyence optical micrometer and high speed DAQ unit. The moving parts of the machine are controlled by an AutomationDirect PLC and I created a custom GUI in C# for the operator interface. The C# GUI interfaces with the PLC and the DAQ unit. The GUI reads the raw data from the DAQ card and calculates the key parameter which is the frequency of vibration. The RMS value is also calculated to determine the validity of the measurement. Daily totals are displayed in a table and data is also stored in an SQL database.
