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Curve profile


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This UZ works like this.

Normal Profile 0.1mm => +/- 0.05mm
Profile 0.1mm UZ -0.1mm => -0.15 / -0.05
Calypso profile settings - wrong - with this setup ( image ) you need to place -0.15 and tolerance 0.1

This ISO norm is telling how muh is centerline of tolerance band is deviating from center. Negative means into material.

Here is something to read
viewtopic.php?t=10753
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  • 1 month later...

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Be careful with explaining this. In Calypso you are telling for line profile where is one side of tolerance from nominal.
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Background
1-The offset inside the Curveform was intergrated in CALYPSO 4.0.
This was done according to a customer request:
We have had e.g. evaluated 6 Curveform's. Please shift the tolerance by the average value of min(midDev(1-6)) and max(maxDev(1-6)). As result those min-max are symmetrical acording to the tolerance.
It's only a real qualification of the simple form deviation, therefor the range of the extrem values are calculated.
2-The line form according to the international standards was realized later and uses different mathe in the background. Especially the calculation of the actual inside lineform is different actual = 2*(max|minDev|, |maxDev|) ≠ Range.
3-Select the characteristic in CALYPSO according to the request from the specification "CurveForm or LineForm".

LineForm: LineForm see other content
CurveForm: Example as PDF

41.pdf

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Hello Martin:
How to justify form and line profile.
I noticed without datum measured data was 0.179 (min -0.179 & max -0.047), but when we used datum
reference, measured data showed 0.421. Please see the picture.

How to justify it. Please explain in detail about profile evaluation method in calypso.

Thank you

Curve Sect B-B_New Plot.pdf

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Hello K Zack

1 - Please check the comments in our pdf
2 - The additional pdf (PageNo 6) explains the calculation in the background. In that example the UZ = -0.005 and tolerance = 0.010.

I don't have CALYPSO 2018 (6.6) so CALYPSO 2021 (7.2) is used.

Good luck

CurveSect_B-B_NewPlot_Comment.pdf4.pdf

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OK. I first wanted to apologize because I misinterpreted how Calypso Profiles were setup. I originally assumed that Calypso was aligned closer to the ISO spec, but after some testing it appears that it is closer to the ASME spec.

Having said all of that, what an absolute convoluted mess this all is. I've never been a huge fan of Profile to begin with, and the allowance for anything other than a standard bilateral tolerance zone is just nonsense and lazy engineering. /rant

I went back and spent more time on this with a couple of colleagues, and I believe now that I have a better understanding of how to properly tackle this inside of Calypso.

The UZ that is used in ISO and the Ⓤ that is used in ASME are not the same thing at all. On their own they make perfect sense, but there can be confusion when trying to translate from one standard to the other.

Let's take a look at an example from the ASME spec. 5381_eab27ed2aa7a228e03c357c58496b811.png
The first value is the total tolerance. The value after the Ⓤ gives the amount of the tolerance that is on the outside of the material.

How would you build this in Calypso? 5381_6633713b7870ff6d0c4d31bdd83bda0c.png

Let's take a look at an example from the ISO spec. 4746_bce72056dded999b5f38b65916d56807.png
The value after the UZ symbol in brackets gives the direction and the amount that the nominal profile is offset, so in this example would be offset 0.1mm outside of the material. The value before the UZ symbol is the symmetrical tolerance zone around the new nominal, so in this example it would be 0.1mm symmetrically disposed around the new nominal.

If you were to sketch this, it would look like this. 4746_d98a164eb7d4cf65cb7cae8ab6efe444.png
The Purple line represents the original nominal, the dashed line represents the new nominal that is offset from the original by 0.1mm, and the two solid black lines represent the tolerance band that is symmetrically disposed around the new nominal.

The key difference here between the ASME and ISO specifications is that the UZ in the ISO spec is the direction and amount that the original nominal is offset. In the ASME spec, you do not offset the nominal, you are just stating how much of the tolerance is outside the material.

So, how would you do this in Calypso? Well first we need to translate what is stated in the ISO drawing to how it would be stated in an ASME drawing. The translation is somewhat straightforward.
4746_bce72056dded999b5f38b65916d56807.png
You take the first value and divide it by 2. In this example: 0.1/2 = 0.05. Then you add that value to the second value (the value after the UZ). The big thing to remember here is to always keep the direction sign of the UZ value. In this example the UZ value is +0.1, so 0.05 + 0.1 = 0.15. The 0.15 is what you will place in the Tolerance (one side) box.
659_756b08483fc715cdbe62797ea908cba4.png
If you translate the callout this way, you should never need to switch the directions of the Inside/Outside switch - it should always be set to Outside. In addition, the Tolerance (one side) box will accept a negative value with no issue.

There are other ways that you could handle the ISO drawing inside of Calypso.

The easiest would be going into the Curve itself and offsetting the nominal in the correct direction and the correct amount as stated by the UZ. Modify Nominals - in vector direction - Translation - Length. If you do this, and do this correctly then you can technically just use a normal Bilateral tolerance zone.

I hope that this helps clear up some confusion, and like I said, I apologize for stating incorrectly how this should have been interpreted.

Thanks.

Picture4.pngPicture3.pngPicture2.pngPicture1.png

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That's what i warned about. Calypso has different setup for that ( it's bad that you have to use calculator to be sure 🤣 )
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