Another method of error proofing the machine process is monitoring system on the machine controllers today. Specifically, I've got a case study and it’s one of my favorites and really a wonderful example of a Poka-yoke process that saves you a lot of money. 

This customer was applying a spindle load monitoring system against a particular tool that had historically a lot of failures. There was a combination tool that would typically fail three to four times a week. This occurred due to some type of insert issue or problem in the tool that could not be detected easily. So the tool would fail, they would have to stop the process, replace the inserts on the tool, and in some cases they would have to either scrap the part or re-work the part in this particular tool because it was a combination tool was $290 per tool. 

By eliminating the breakage by applying spindle load monitoring and letting the control monitor the energy being used by the motor, based on the condition of the inserts of the tool, if the average draw went up too high beyond boundaries identified by this particular customer, then the machine would flag a warning. It could stop the process or go to a redundant tool stored in the tool magazine to finish the next process. By that method, they eliminated breakage of these tools. If you analyze the savings of these broken tools at three to four per week, at $290 a tool, you can quickly calculate that there's a cost savings of $26,000.

The customer very quickly informed me that $26,000 is just the half of it. He said, “We’ve also eliminated all the down time associated with re-establishing the process when the tool broke. We’ve eliminated the extra labor it took to recover the machine and to re-set the tool, and we eliminated scrap parts.”  He also went on, “Really, what it came to was an annual cost savings of about $40,000.”  It’s a good example of another Poka-yoke process that can be applied effectively utilizing the control technology. 

I have another slide showing something that we call, ‘Spindle Upper and Lower Limit.’  If you look at the diagrams down below, basically what this feature capability can do is identify what we just explained on the previous slide and that is that the cutting addition becomes more demanding, basically represented by the amperage draw or the torque of the spindle motor. This can be detected electronically and a process can be stopped before any damage occurs. 

On the other hand, the opposite case of that would indicate that we also can monitor lower levels. What this can do is identify a misplaced part on a fixture. It is an advantage that this has provided. If a part is misloaded and you’re attempting to machine a feature and you're not getting any amperage draw as you should, then the control in the machine can interpret that as a misplaced part again stop the process, and give you an opportunity to correct the process before any damage or errors occur.