Wall thickness control

[ivanmr4]

Hello,

I have a part that is something similar to the example in the attached file. We need to control the thickness of the wall all along the cone and all around it, to be sure that is not under a minimum (9 in the example).

1. By having a dimension like the one in the example (10±1mm) are we impliying that the supplier needs to measure and assure the wall thickness for all the points of the cone?
2. Is there a better way to mark from where to where this thickness is valid? (as it is shown in the sketch, it goes from a point in the inner surface to a point in the outer surface)
3. Could it be dimensioned with a geometric tolerances in a cleverer way?

Thank you very much for your help.

 

[greenimi]

3.) Well, I could if you use profile on both surfaces (inner surface and outer surface) to the same datum reference frame.
1.) Definition does not imply any measurements. (so it is not mandatory)
2.) Related with #3: use profile between points to improve clarity (ex from A to B for the outer surface and from C to D on the inner surface)

 

[chez311]

ivanmr4,

I think you'll find that there is quite a bit of variation depending on how exactly the wall thickness is measured - the directly toleranced (+/-) wall thickness allows for some wiggle room in interpretation.

*Edit - saw greenimi's post after I submitted - I agree as he noted, what might be a better idea is to hold the inner and outer surfaces of said wall to a profile tolerance with the same datum references - thereby holding it in simultaneous requirements (or perhaps the "2X" notation could be used). Just ensure the minimum distance between the two profile zones is 9mm.

 

[ivanmr4]

Thank you so much for your answers! I will update it using profile tolerances.

 

[drawoh]

ivanmr4,

If the thickness is what you want controlled, you should specify the thickness, as you have done. A profile tolerance on the inside and outside faces could be very much less critical. The only problems I see are the tapers of the feature at the top and bottom.

--
JHG