Task# 106458 MMB, LMB (Maximum material boundary and Least material boundary)

huangyhg

MMB, LMB (Maximum material boundary and Least material boundary) of datums for true position and profile
<< Mike Wilson  --  09/17/09  18:38:17>>
MMB, LMB (Maximum material boundary and Least material boundary) of datums
         1 week
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<< Don Turcotte (Documentation Notes)  --  11/10/09  15:42:51>>
Sent e-mail to Jared:
Please change this section:
According to the Y14.5 2009 standard, you can now use material boundaries in your feature control frames.
" Maximum Material Boundary (MMB) - This boundary is the smallest value containing the datum feature of size while maintaining the precedence of multiple datum features. It functions with features of size. When associated with a datum listed in a feature control frame, it includes all the effects of size or tolerances (preceding position or orientation tolerances on the datum feature) relative to datums in a higher precedence. Precedence in a FCF moves from left to right.
" Least Material Boundary (LMB) - This boundary is the opposite of MMB. It is the largest value containing the datum feature of size while maintaining the precedence of multiple datum features.
To the following:
Following the Y14.5-2009 standard, PC-DMIS now calculates datum material boundaries as follows:
         Maximum Material Boundary (MMB) -  When the user specifies circle-M on a datum feature of size,  PC-DMIS calculates the datum maximum material boundary (MMB) by including the effects of size and any preceding position or orientation tolerances on the datum feature, while respecting the datum order of precedence as specified in the ASME Y14.5-2009 standard.  Precedence in a  FCF moves from left to right.
         Least Material Boundary (LMB) - When the user specifies circle-L on a datum feature of size,  PC-DMIS calculates the datum least material boundary (LMB) by including the effects of size and any preceding position or orientation tolerances on the datum feature, while respecting the datum order of precedence as specified in the ASME Y14.5-2009 standard.  Precedence in a  FCF moves from left to right
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<< Don Turcotte (Review Notes)  --  11/10/09  15:02:15>>
When user clears the MMB size (or enters 0), this field now shows correctly as <size> and does not appear in the report callout or the graphics window callout.  This problem is fixed.
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<< Don Turcotte (Documentation Notes)  --  11/10/09  14:56:07>>
Reviewed documentation. OK
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<< Jared Hess (Documentation Notes)  --  11/09/09  14:06:57>>
Don, the updated documentation is now available:
http://10.57.112.13/WAIhelp/Core/feature_control_frames/Using_Maximum_Material_Boundary_(MMB)_and_Least_Material_Boundary_(LMB).htm
Thanks.
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<< Yanhua Huang (Test Notes)  --  11/09/09  22:43:21>>
fixed.
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<< Yanhua Huang (Review Notes)  --  11/09/09  22:43:14>>
fixed - When the user entered MMB size is 0, this should display as <size> in the FCF editor dialog and not display at all in the report or graphics window callouts (0 means no user MMB size entered).
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<< Don Turcotte (Review Notes)  --  11/05/09  10:09:02>>
Yanhua,
Your fixes are correct.  
However, I found an additional (small) problem.  When the user entered MMB size is 0, this should display as <size> in the FCF editor dialog and not display at all in the report or graphics window callouts (0 means no user MMB size entered).
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<< Yanhua Huang (Development Notes)  --  11/04/09  15:18:39>>
3. The bonus in the "Size" table of the report should remain the same when change FIT TO DATUMS from "Yes" to "No".
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<< Don Turcotte (Documentation Notes)  --  11/03/09  09:50:45>>
Sent Jared amended documentation.
Jared,

I have amended your documentation.  In general, I think it is easier simply to refer the user to the standards document for a fully explanation rather than try to give an exhaustive explanation ourselves.

Regards,
Don


Using Maximum Material Boundary (MMB) and Least Material Boundary (LMB)
The ASME Y14.5-2009 standard now specifies how both the size and position or orientation tolerances of a datum feature are to be used in calculating the datum MMB or LMB.  The user should refer to “ASME Y14.5-2009 Dimensioning and Tolerancing” section 4.11.6 “Determining Size of Datum Feature Simulators at MMB” and succeeding sections on LMB.  Fig-4-16 “Example Calculations of Maximum Material Boundary” in the ASME standards document provides examples of how the MMB boundary is calculated for a datum feature taking into account both the size of the datum feature and position or orientation tolerances on the datum feature.
§         Maximum Material Boundary (MMB) - This boundary is the smallest value containing the datum feature of size while maintaining the precedence of multiple datum features. It functions with features of size. When associated with a datum listed in a feature control frame, it includes all the effects of size or tolerances (preceding position or orientation tolerances on the datum feature) relative to datums in a higher precedence. Precedence in a FCF moves from left to right.
§         Least Material Boundary (LMB) - This boundary is the opposite of MMB. It is the largest value containing the datum feature of size while maintaining the precedence of multiple datum features.
Stating a Specific Boundary
If you want to define a specific boundary perhaps because the implied boundary is not clear, using the Feature Control Frame Editor you can explicitly state the boundary by enclosing it within brackets immediately following the applicable datum feature reference and any modifier following that datum feature reference (this value represents the size of the material boundary and will be used by PC-DMIS to calculate the bonus on the datum feature, disregarding any preceding position or orientation tolerances on the datum feature):
(show example of FCF editor w/ MMC here once PCDMIS is working)

Note that PC-DMIS does not support the use of “BSC” or “BASIC”.
Using the terms "BSC" or "BASIC" indicates that the datum feature simulator is located at the datum feature's basic location.
(show example of FCF editor w/ BASIC here once PCDMIS is working)
(show example of FCF editor w/ LMC here once PCDMIS is working
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<< Jared Hess (Test Notes)  --  10/30/09  14:26:47>>
Latest release build, build 24, still has the same problem as build 20 with regards to displaying stuff in Feature Control Frame editor.
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<< Yanhua Huang (Review Notes)  --  10/30/09  23:11:32>>
Fixed - When the datum is at RMB, we should hide the [diameter size]
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<< Yanhua Huang (Review Notes)  --  10/30/09  23:09:30>>
fixed #1 - When the datum is at RMB, we should hide the [diameter size].
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<< Yanhua Huang (Development Notes)  --  10/30/09  23:08:38>>
Fixed #1. When the datum is at RMB, we should hide the [diameter size].
Leave #2. The MMB size should be available only with ASME Y14.5 (not ISO 1101).
In older versions, it seems  true position always use the same math for ASME and ISO.
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<< Jared Hess (Documentation Notes)  --  10/29/09  16:08:10>>
Forgot to add the link for what I have for documentation so far:
http://10.57.112.13/WAIhelp/Core/feature_control_frames/Using_Maximum_Material_Boundary_(MMB)_and_Least_Material_Boundary_(LMB).htm
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<< Jared Hess (Test Notes)  --  10/29/09  16:01:50>>
I could not get the Feature Control Frame editor to display the FCFs in the QA RELEASE diskset dated Oct 28 (build 20). They just show up empty. (see the attached video Bug106458.7z). This needs to be fixed before I can continue documenting since I need it to function for screen captures. I used the part program files already attached to this task.
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<< Jared Hess (Documentation Notes)  --  10/29/09  16:01:01>>
I tried to come up with something, but after researching this for some time today, I still don't really understand it. Here's what I have, but I'm sure it's incorrect and needs some work. Please supply me with the documentation I should add.
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<< Yanhua Huang (Review Notes)  --  10/29/09  21:54:14>>
Found two issues.
1. When the datum is at RMB, we should hide the [diameter size].
2. The MMB size should be available only with ASME Y14.5 (not ISO 1101).
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<< Don Ruggieri (Test Notes)  --  10/27/09  13:11:56>>
I have been testing this off-line and on-line (edited) with Don's test program and differing scenarios to alter the bonus values, and I am satisfied that it is working as intended.
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<< Don Turcotte (Review Notes)  --  10/21/09  17:08:12>>
Fixed additional problem in QA Release:
  Need to check for change in MMB Size in CPCDFeatCtrlFrm::NeedUpdateInternalCommands(...) and CPCDFeatCtrlFrm::NeedUpdateInternalCommands_IgnoreTols(...).
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<< Don Turcotte (Review Notes)  --  10/21/09  15:21:44>>
I have added the user entered MMB Size to the edit window for both command and summary modes.  The problem with FeatCtrlFrmUtil.h was fixed by Yanhua with her upload for 106460.
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<< Don Turcotte (Development Notes)  --  10/20/09  17:14:56>>
The problem that Andy noted about FEATCTRLFRMUTIL.H has been fixed by Yanhua in her upload for 106460.
I am working at adding the user entered material boundary size to the edit window (command and summary modes) in QA Release repo pcdmis2010_tp1 tip.
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<< Andy Roberts (Development Notes)  --  10/20/09  14:02:11>>
Reviewed with Don Turcotte.  Also reviewed GD&T related to this task.
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<< Andy Roberts (Review Notes)  --  10/20/09  13:53:37>>
Also looks like we need to add the user entered material boundary size to the edit window (command and summary mode)
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<< Andy Roberts (Review Notes)  --  10/20/09  13:32:47>>
FEATCTRLFRMUTIL.H has three bit vectors with the same index.  Starting with CAN_USE_DATUMA_MMB_SIZE_LINE3.
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<< Don Turcotte (Development Notes)  --  10/20/09  15:56:43>>
Reviewed this with Andy.  He has noted some problems.
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<< Changes made by Don Turcotte (Documentation Notes) -- 10/06/09  13:16:13>>
Documentation on datums should explain material boundary for datums as described in Y14.5 2009 (extract is attached to the associated ER 505712) as well as the ability of the user to enter a specific material boundary size for datums of size.
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<< Changes made by Don Turcotte (Review Notes) -- 10/06/09  13:16:13>>
I have completed this including user entered material boundary size.  (Not implemented is user entered BSC or BASIC).
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<< Don Turcotte (Development Notes)  --  10/01/09  12:20:42>>
I am working on hooking up the user entered MMB value to the calculations.  I should be able to finish this up next week.
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<< Don Turcotte (Development Notes)  --  09/30/09  17:35:57>>
I am making progress on this.  I can now enter user defined MMB values for the datums at material condition.
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<< Don Turcotte (Development Notes)  --  09/29/09  17:31:27>>
Continuing work on implementing a user entered datum MMB/LMB boundary size.
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<< Don Turcotte (Development Notes)  --  09/24/09  12:07:21>>
I am working at implementing a user entered datum MMB/LMB boundary value.  There may be problems with the tolal length of the GD&T line in the FCF editor dialog page.
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<< Don Turcotte (Development Notes)  --  09/23/09  17:17:21>>
I have implemented the datum order of precedence logic when calculating datum MMB/LMB.  I have tested this and attached my test program.
I am looking at implementing a user entered datum MMB/LMB boundary value.
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<< Don Turcotte (Development Notes)  --  09/22/09  17:16:18>>
I am working at implementing this enhancement.
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<< Don Turcotte (Development Notes)  --  09/22/09  10:40:16>>
Based on ER 505712 - document attached to the ER.
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