Re: Variable R & R study for 8 Cavities tool - die casting industry
Could you expand this statement? I am dealing with small rubber parts molded in tools having hundreds of unmarked cavities.
The point of gage R&R is to determine if the gage is the correct gage for the job. That is not related to the number of cavities, except for the fact that the sample of parts you are verifying with the gage should be representative the the amount of variation that specific dimension will have. Which cavities the samples come from are not important.
Also, mark the parts and have the operators measure the dimension at the
exact same location every time.
I prefer 3 operators, one very well trained, one of the least trained that would likely use the gage, and someone in the middle. This generates a result that should be applicable with any potential future operator. I would suspect that is particularly important when measuring rubber!
Make sure you
watch the gage R&R process -
observe the technique variation (another common error). If the gage R&R fails, you may need to control the technique to get it to pass, rather than buy a more expensive gage. If you have the AIAG book, be sure to pull out the list of between and within errors, and watch for them during the Gage R&R process.