Dear friends,
If may choosen parts for R&R study is having with in job variation (ovality, taper) what is should I do, whether I have to mark a position and ensure the gage R&R in that perticular zone are just I can go with this variations. Pl. advise
The with-in part variation in form (e.g., ovality and taper) will show up in Repeatability.
Ideally, you use a gage that can demonstrate repeatability despite this variation in form. However, many times you cannot find such a gage. When this occurs, you must proceduralize a method that will provide this repeatability. This procedure may consist of taking the maximum measurement, the minimum, the average of both, the diameter at a specified distance from the end (for taper), etc.
You must find a method that provides repeatable results and makes sense in the application. For example, if the feature is a tapered hole that must pass a locating pin, you should probably use the minimum diameter.
Marking the location for the next measurement does not make sense unless it is to locate the point at a specified distance because the first, and possibly only, person to measure the feature will not have such a mark to guide them.