PiWeb report display hole Position with MMC condition ONLY

[[LE...]]

Hello everyone.

I am inspecting hole position under Maximum Material Condition(MMC)

However the PiWeb report displays both Standard Position as well as with MMC as indicated with later .M on the report.

This is very confusing to Engineers.

Is there a way to just display one with MMC as indicated with Green underline in the screenshot.

[[Ri...]]

The bottom one is useless to you. The top one is the actual Position. The bottom one is just a statistical calculation of the actual divided by the total tolerance multiplied by the base tolerance. 

[[An...]]

There is a knowledge base article covering this exact question: ZEISS Portal

If you are not US based, I believe you will have to change your location to the US in your ZEISS Portal profile to see the article.

[[Ra...]]

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Still shocked that this is the Zeiss official method of removing the (M).

[[LE...]]

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Hi Richard.

So one displayed with .M is useless.

How can that be. Note Position Tolerance I entered is 0.08 which shows up in +Tol column and result has .M denoted.

 

[[LE...]]

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Hello Andy. I am US based.

[[Jo...]]

MMC changes the tolerance if there is "wiggle room" because the maximum material state is not reached. Meaning biggest allowed inner circle for example or smallest allowed outer circle.

In you picture i cant really tell if this is calculated right.

• There is a mix up of bottom and top right.
• and i got no clue what you are actually measuring here (inner outer whatever)

Lets say top left is an inner element meaning there is way less material than maximal allowed, you could in theorie (although it is nio anyway) add that to your 0,08 for the position. You take the max material condition which is nominal-Tolerance = 4,0491-0,05 =3,9991; Actual- mmc = additon --> 4,1642-3,9991=0,1651; add this to your position tolerance 0,08+0,1651 = 0,2451

Ok i guessed right the numbers add up 🙂

Edited 4 hours ago

[[LE...]]

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Hello Jochen

Thank you so much for you detailed explanation.

Wow. I did not realize the Calypso actually did that Math automatically.

So that where all these values: 0.2450 and 0.2458 come from.

The Names: Top Left and Bottom right indicate the threaded holes on this metal part. they are M5x0.8-6G Through ALL

[[Jo...]]

The naming seemed inconsistend to me compared to the above 🤔

[[LE...]]

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Initially I though I had to keep the Position denoted with .(M) 

So should I remove that and leave the Position without .M instead

Which one should I remove.

Because Engineers go by .08 Tolerance and want to know the value compared to .08

[[Jo...]]

First of all the element is named bottom right and the position top right ...

 

If your engineering wants to see the postion without mmc, than i would create another check for it without mmc active and report both.

For calypso/Piweb details keep to the post from Richard or Andy. I dont work with either.

[[Ri...]]

 

This was one thing I did recently for a customer to help clear up a lot of confusion (especially when needing to show multiple parts in a table). 

The .Max Allowance is the total tolerance for that part/hole (base tolerance + mmc allowance). The .MMC Deviation is the amount the actual position deviated beyond the Max Allowance. It was set to an if statement where if the actual position was less than the max allowance it would just show zero. 

[[LE...]]

Ok Jochen.

I fixed the names.

To recap: I.ll leave both Positions and just verbally instruct Engineer about what value to look at.

So the actual position is 0.2635 as indicated in the Position Window.

But Engineers read  0.0597 (RED BOX) because it is on the same Row where 0.08 is.

So they think the deviation of 0.0597 is not that bad while in reality it's 0.2635 which is 4x bigger value.

[[LE...]]

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Hi Richard.

Jochen did good explanation and I get what you are saying but I'll just have to speak to the Engineer.

Please look at my last response to Jochen.

 

[[LE...]]

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RIchard Can you please show the Math.
I don't understand what do you call  "total tolerance" and  "base tolerance"

Position tolerance call out of the hole is 0.08

How is 0.0757 calculated.

Edited 2 hours ago

[[Iv...]]

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 Slight tangent, but I advise not to apply MMC to threads. I linked a further explanation below, but you can find several more sources with a quick Google search. 

When measuring threads on a CMM, the most feasible approaches are either to capture the major or minor, depending on whether it is an external or internal thread (minor in your case). Both major and minor are somewhat irrelevant when focusing on the functionality of threads, since the PD is generally the key element. So potentially, the bonus you are seeing here does not correlate to the functional use and can lead to false assumptions. 

https://www.gdandtbasics.com/no-bonus-tolerance-modifier-on-threaded-holes/

I would still recommend learning about that .(M) line, as others have mentioned; it is possible to remove it, and the ZEISS portal has walkthrough articles. 

[[LE...]]

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Thanks Ivan.I am scanning the minor diameter of Internal holes using HELIX path in the Strategy.

I did read about the procedure to remove .M but I guess I'll just leave it there because it has the positional tolerance that I input.

But I'll verbally instruct engineer not to pay attention to value that is displayed on that Row.

I am still trying to figure out where did 0.0757 come from.

Was it calculated or Measured.

[[Ri...]]

The 0.0757 is just math of (0.2318/0.2450)*0.080.

Actual Position = 0.2318

Total Tolerance = ( Base Tolerance (0.080) + MMC Tolerance ((Actual Hole Size = 4.1642) - (Hole Size MMC = 3.9991) = 0.1651) ) = 0.2450

Base Tolerance = 0.080

.(M) = ((0.2318/0.2450) * 0.080) = 0.0757

[[Ze...]]

Notice that percentage is the same for each line. You can think of it as a percentage of the tolerance used. 

[[LE...]]

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Thanks so much Richard.

Finally I understand what's going on now.

 

[[LE...]]

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Thanks Zen