Doubt in Cylindricity 3

[ASHWA]

Dear All,
Having a basic doubt in Cylindricity,

Here,
Max. limit is 1.000 + 0.010 + 0.001(Cylindricity) = 1.011
Min. limit is 1.000 - 0.010 - 0.001 (Cylindricity) = 0.989.

Is this correct? Pl. clarify.

 

[3DDave]

For ISO or ASME?

 

[ASHWA]

3DDave (Aerospace),
for ASME.

 

[CheckerHater]

Somehow like this:

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[Belanger]

It depends on what you mean by max/min limit, but...
The max limit would be 1.010
The min limit would be 0.990

In other words, cylindricity doesn't override Rule #1 of ASME Y14.5.



John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[jassco]

Hi,ANBU SARAVANAN:

The cylindricity feature control frame does not control size of the feature. Also, I think you need a diameter symbol in your feature control frame because the tolerance zone is in a cylindrical shape (small though).

Best regards,

Alex

 

[Belanger]

Also, I think you need a diameter symbol in your feature control frame

No -- it is correct without the diameter symbol. The tolerance zone is a radial bandwidth that happens to wrap around, but the number itself is not a diameter.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

 

[jassco]

Hi,

Belanger is correct. I was confused with straightness.

Best regards,

Alex

 

[ASHWA]

Thanks Friends,
So my cylindrical part should not override Rule No. 1, Got it.

I need a further clarification w.r.t Free state condition dim's,

Is this dim's correct wrt Free state?

Pl. clarify. Thanks.

 

[greenimi]

In free state rule#1 is nullified/ canceled, hence cylindricity does not have to be smaller than the size dimension.

 

[axym]

Hi All,

I agree with Belanger.

Evan Janeshewski

Axymetrix Quality Engineering Inc.

http://www.axymetrix.ca

 

[Burunduk]

ANBU SARAVANAN,
When the MAX and MIN limits are mentioned, these terms usually describe the limits of size of a feature. The limits of size in your example are still 1.010 (MAX limit, AKA the MMC limit) and 0.990 (MIN limit, AKA the LMC limit). This is regardless of the cylindricity tolerance and the free state modifier.
What the free state modified does is it enlarges the Outer Boundary of the cylinder from 1.010 (the boundary that exists with rule#1) to the value generated by the effects of the feature's MMC and the cylindricity tolerance. This equals 1.011. The Outer Boundary is the smallest theoretical cylinder in which you could fit the actual cylinder of the largest size and form error as allowed by the limits of size and the cylindricity tolerance. The Inner Boundary, the largest theoretical cylinder which can be fitted all inside the actual cylinder of the smallest size and largest deformation allowed by the cylindricity tolerance, equals 0.989, which is the same with or without rule #1.

 

[ASHWA]

Thanks CheckerHater (Mechanical), Belanger (Automotive), jassco (Mechanical), greenimi (Mechanical), axym (Industrial), Burunduk (Mechanical).

Thanks all for your inputs, importantly doubt is cleared.