# Profile callout to a basic dimension calculation

#### DeKamp

##### Involved In Discussions
Hello, and Thank you in advance for any information you can provide. I apologize if this is not in the correct category but am having a few issues with "How to calculate Surface profile". On the attached snapshot, you can see that all the Basic Dim's are controlled via the Profile callouts.
1) does this insinuate that the Basics have a ± tolerance in accordance with their respective profile callouts?
For example: Ballooned Item #1 is with Ballooned Item #6 with a profile of 0.8... technically speaking then the Basic would have a ±0.4 tolerance zone, correct?
2) if my measurement from the Basic 104.8 equals 104.721 then how would I calculate the Profile? How would I report it?

Or am I way off? Any feedback is appreciated. Thank you.

#### Scanton

##### Quite Involved in Discussions
I believe features 1, 3 & 9 would have a +/- tolerance and features 2, 4, 5, 6, 7 & 8 are maximum limit.
Features like Flatness and Perpendicularity are specified as maximum.

#### DeKamp

##### Involved In Discussions
Yes, that is correct for the Perp's and Flats callout's. But my concern is how to report the Profile of Surface. is there a formula I can use? Does it coincide with the Basic Dimensions at all? Etc.

#### Matt's Quality Handle

##### Involved In Discussions
The basics provide a nominal from which the surface profile is measured. In this case, every point on the surface indicate by 6 must be within .4 (assuming) mm from a plane that is:
• Perpendicular to A
• Perpendicular to B
• Parallel to C
• Located 104.8 (again, assuming) mm from C
Typically surface profiles are scanned and the high/low points are reported, and both must be within the spec (+/- .4) . In your case, you would have -.079 as either the min or the max. I'm assuming it's the max, as it sounds like it was measured with a caliper/mic.

What tool did you use to measure 104.721?

#### Johnnymo62

##### Haste Makes Waste
My experience is that BASIC dimensions are reported as the data measured with no pass or fail.

#### Matt's Quality Handle

##### Involved In Discussions
I believe features 1, 3 & 9 would have a +/- tolerance and features 2, 4, 5, 6, 7 & 8 are maximum limit.
Features like Flatness and Perpendicularity are specified as maximum.
Also, 1, 3, and 9 wouldn't have a tolerance, but may be reported depending on customer preference. IMO, they serve as an "idiot" check to ensure that your CAD model, CMM program has the correct nominal, but should not be evaluated against ANY tolerance.

#### DeKamp

##### Involved In Discussions
The basics provide a nominal from which the surface profile is measured. In this case, every point on the surface indicate by 6 must be within .4 (assuming) mm from a plane that is:
• Perpendicular to A
• Perpendicular to B
• Parallel to C
• Located 104.8 (again, assuming) mm from C
Typically surface profiles are scanned and the high/low points are reported, and both must be within the spec (+/- .4) . In your case, you would have -.079 as either the min or the max. I'm assuming it's the max, as it sounds like it was measured with a caliper/mic.

What tool did you use to measure 104.721?

I used our CMM. Point on one side to the plane on the other. With it being 0.079 would I (2x) to get .158?

#### Matt's Quality Handle

##### Involved In Discussions
I used our CMM. Point on one side to the plane on the other. With it being 0.079 would I (2x) to get .158?

The profile isn't asking for a single point, it's asking about EVERY point on that surface. A CMM should be able to evaluate it as a profile, but you should take multiple points. Each of those points would be evaluated against the boundary, depending on that point's distance from -C-.

I would report the single point that you've taken as -0.079 (- indicates the less material direction).

If you measured another point at 104.400, the report should read -0.400/-0.079. and would just pass
If you measured a third point at 104.000, the report should read -0.800/-0.079 and should fail.

#### DeKamp

##### Involved In Discussions
The profile isn't asking for a single point, it's asking about EVERY point on that surface. A CMM should be able to evaluate it as a profile, but you should take multiple points. Each of those points would be evaluated against the boundary, depending on that point's distance from -C-.

I would report the single point that you've taken as -0.079 (- indicates the less material direction).

If you measured another point at 104.400, the report should read -0.400/-0.079. and would just pass
If you measured a third point at 104.000, the report should read -0.800/-0.079 and should fail.

I took 20 individual points along the surface of the "Wall" Went to report Profile and it will not allow with individual points. Lines, or planes work to report this. Any ideas?

#### Matt's Quality Handle

##### Involved In Discussions
OK, the individual points should be taken (collected) as a single element (plane or other type of surface). Then evaluate the surface as a profile.

It's been a while that I've used any CMM software, and even then there are variations between the different softwares (and settings/prefs within each software). I'm reaching the end of my expertise. Maybe some other Covers with CMM experience can help you go farther.