First let me say that I am not a machinist so I apologize if my question seems unusual.
I am a metrologies working with Machinists and I am trying to better understand the machining process so that I can tailor the inspection process to the machining AND help the machinist optimize their process.
At the moment I am trying to understand the signals that the machine can communicate to the operator. We have an Okuma lathe that can monitor and alarm based on back pressure or load to a given axis or tool. I am trying to identify a way to set an alarm based on load limits that spike up or down in an unusual way which would indicate a "special cause" in the process. This special cause (I believe) would tell us that either the tool chipped/broke (spike down) or the tool picked up a chip wrap and is cutting with the chip (spike up).
The goal is to demonstrate that certain features represent the process and as a result the entire part does not require 100% inspection once it can be determined that the process is in control.
The concern appears to be that we are using a 0.006 radius insert to cut the finishing pass on the part and the little variation in pressure for this tool would not be enough to register on the chart.
My questions are as follows:
1) Is it possible to set the load monitor to units that are tuned to individual tools within a program. Currently the operator is showing me that the load monitors XX% relative to 100% warning limits are set at 50% and 60%. The resolution of 1% is concerning to me because I have no way of knowing or understanding what the 1% means... 1% of what? What if I need to see 0.05% in order to set my alarm that tells me I have a special cause?
2) I have read that when you start making a new program you do a "test cut" and that the 100% load limit is relative to the maximum pressure that it took to make the test cut. Are these 2 things related? How do I tell my machine that I am making a test cut? and how do I tell my machine to use a different 100% for each tool that I am using?
If my roughing tool is hogging out 90% of the material at a fast rate and my finish tool goes in and cleans up the surface delicately then my 100% becomes of little value...
3) Am I chasing a rabbit hole hear and if so can someone please point me in a more productive direction?