2WAY DATUM PROFILE TOLERNCE SIZE

[Remol]

Can you all help me to find out my Go/No Go gauge size based on this picture?
2 way slot datum hole of profile tolerance of 0.2.

 

[nry67]

Hello

GO / NO GO 14.6x7.6 / 15.4x8.4 If we discuss only for the size of your "2 way slot" and not for your location related to A B C

 

[greenimi]

My Go/ No-Go sizes are the following:

15-0.2 = 14.8 / 15+0.2 = 15.2 for the horizontal dimension
8-0.2 = 7.8 / 8+0.2 = 8.2 - for the vertical dimension

The assumption I made was the profile is all around (even the small circle is missing from the callout) so the feature control frame is applied to the entire slot and not only to the upper surface.
(even that you cannot apply position to a surface in ASME). And, as stated before, I also assumed ASME is the standard the OP is working on.

This is not checking the location related to A|B(M)|C|

 

[nry67]

The profil is applied allaround of the feature, in this case the tolrance +/- 0.2 is apply 2 times. (for each side)

 

[greenimi]

The profil is applied allaround of the feature, in this case the tolrance +/- 0.2 is apply 2 times. (for each side)

So, you agree or disagree with my numbers?

 

[Belanger]

The profile is equally disposed on each side of nominal, so it becomes ± 0.1, but applied twice because of all-around. So the allowed limits are 14.8 / 15.2 and 7.8 / 8.2.

However, a go/no-go gage in that sense would not check the full requirement of profile (even setting the position callout aside). Recall that form is an integral part of profile too.

 

[greenimi]

However, a go/no-go gage in that sense would not check the full requirement of profile (even setting the position callout aside). Recall that form is an integral part of profile too.

Can you use the new delta symbol here?
And if "delta" is used how the size would be calculated?

 

[Belanger]

The dynamic modifier could be used if it's changed to a composite-type profile callout; that relaxes size while maintaining tighter form. But I don't think that's the intent here.

Given the current callout, my earlier comment just meant that a go/no-go gage simulating that elongated shape would only hit the inner extremities.
A no-go gage shouldn't be a full perimeter; it should sample opposing two-point places, but that is fraught with issues here because this is elongated, not a nice cylindrical shape.

 

[nry67]

To Greenimmi


Yes of course... i'm confuse... the value it's +/- 0.1 applied 2 times (for each side) not 0.2 ---> 7.8 x 14.8 and 8.2 x 15.2

 

[greenimi]

nry67,

Make a sketch and convience yourself about the validity of my answer (and J-P Belanger's answer too, which match mine)

The bottom line

GO / NO GO 14.6x7.6 / 15.4x8.4 .....

Your above answer is just wrong.



15 and 8 are the center of the tolerance zone. The tolerance zone is ±0.1 on one side and another ± 0.1 on the opposite side

Could you, please, explain how did you get your values of 14.6x7.6 / 15.4x8.4?
Because you have shown only the final values, but not how did you come up with those.

 

[amanz]

Hello, I am still learning but I agree with greenimi.

nry67, I made the same mistake as you.