Exactly how did you do the gr&r? Did you calculate the gr&r using .00016 as your total tolerance? Did you do it using the exact method and parts that you will be measuring in process? I guess the reason I ask is that tolerance is really tight and the average cmm probably would struggle...
1. would a cmm report .023 or .046 for concentricity in the example in the link?
2. so the statement that I hear a lot that "in general tir is double concentricity" is false? (assuming roundness is perfect).
I realize there has been several of these threads but the more I read the more I get confused. Unfortunately there is no one where I work to go to with these questions. For the longest time I was always under the assumption that "concentricty for the most part will be half your tir" assuming...
"How is this - NO!
Your parallelism of the C/L of the feature references one side of the same feature. Go figure that one. Take the parallelism out for sure.
Positional to datum B is OK. This is just showing symmetry and it is only for the width of the feature so that is OK.
I don't know how...
The total runout is to be checked using datum A and Datum B of equal importance, hence the A-B in the frame. Datum A and Datum B are our bearing journals.
Heckler, I agree, that parallelism callout is wrong. I guess the more that I look at it, the more symmetry seems to fit what the drafter...
How would you inspect runout on two flats? I agree, some kind of runout would be the correct callout but inspecting runout on flats???
I would also like to know if the callouts are correct. Unfortunately our drafting team has little to no knowledge in the GD&T area, our quality department has...
here is a copy of the print I am talking about
http://i168.photobucket.com/albums/u179/mopar4u/positionaltolerance.jpg
I have issues with the true postion .002 and the paralellism .005 callout.
With the true position are you supposed to assume that the drafter wants you to find the symmetry...
