What has Changed?

It is common when automation stops, to make assumptions about the cause of the stop without considering that it could have been caused by something simple.  If a machine has been running for a period of time, then stops, it is appropriate to ask the question, “What changed?”.  

Did something move?  The CNC, the Robot Cart.  We’ve seen CNC’s move 1-3” from the original mount position over the course of a couple days, depending on how they are used.  CNC’s moving 0.03” can cause automation issues.  Check cart position.  Perform regular maintenance, checking for loose connections on hardware (e.g., robot mount).

Did a new process get introduced?  Something as simple as adding a new tool in the CNC can cause a change that interrupts the automation process.

For example, VersaBuilt added a Shell Mill for a new part on a CNC that had been running robotically for months.  After a couple of hours running the new part, the system faulted because the door was stuck.  Hours were spent trying to find the problem with the door opener.  Initially, we focused our attention on the door cylinder and shop air pressure.  After further review, we realized it was caused by chips getting thrown by the Shell Mill onto the door rail.  The tool path of the Shell Mill was modified to throw chips in a different direction and the problem was resolved.  If we started with “what changed?”, we may have targeted the root cause of the problem faster.

Did something get modified?For example, a new set of  MultiGrip Jaws introduced to an existing part may require a change to the part configuration.  

Did something get damaged?  It is common and understandable to make mistakes or have accidents.  These adverse events can cause things to move or cause system failures.  For example, if the MultiGrip Jaws get dropped on the floor during handling, the cross-pins may get bent, causing a number of issues that may misdirect your troubleshooting.  These issues could be:

• Jaws mispicked by the robot
• Jaws misloaded into the MultiGrip Vises
• Machining out of tolerance (z-height changes to the part)