Reporting & Datum Referencing

After taking a measurement and reporting the True Position (TP) WITH datum references, I want the report to omit the datum data that is being referenced, but when I delete it from the DIM the measurement changes and I don't understand why.

Is deleting the data from the DIM removing the datum references completely?

Is there a way to remove that data from the report, but maintain the appropriate TP deviation?

Could someone please explain?

The images show WITH datum references and WITHOUT.

Attached Files

WilliamL over 1 year ago

What version of PCDMIS are you using? I've not had a chance to work with Xact dimensioning, but in newer versions with GeoTol, there is a tab called "Nominals" or something similar to check off which items to include in reporting?

Edit: On second look, is this a Legacy Dimension?

Attached Files
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
R2ah1ze1l over 1 year ago

use the datums to create your alignment then report the feature(s) to the correct X/Y/Z axis and you will not need the datums referenced in your output.
FYI- legacy output(which is what you appear to be using) does not handle (L)/(M) bonus correctly in reporting for the datum shift.
If you are trying to utilize needed tolerance shift allowance from your datum you should be reporting using FCF or Geo-Tol.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
KJAdams over 1 year ago in reply to WilliamL

2018 R2

Correct, it is a legacy dimension. I'm still in training and the Xact measuring isn't what my leader wants me to use.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
KJAdams over 1 year ago in reply to R2ah1ze1l

Are you saying referencing the datums in the TP measurement is redundant because I am already aligned to A, B, & C?
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
R2ah1ze1l over 1 year ago

KJAdams, I'm saying that you will have an incorrect tolerance boundary produced using LMC/MMC on datum features with legacy position outputs.
But yes, if you are already aligned to the based on the datum reference frame, it is redundant to also select the datum features in your legacy output(s).
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
vpt.se over 1 year ago in reply to R2ah1ze1l

...but on the other hand, having them in the evaluation tells the next guy reading the report that it is done according to drawing. So, no - don't leave them out. If I read your report and you are not using the datums, I'd say that it is incorrect just because you are not using datums in the evaluation...

Also, the information from the datums is actually valuable even if you might not think so. You have MMC on the secondary datum which should be reported to know how much datum shift that datum allows. I see no reason why you should remove that.

This is like the "please remove the datum shift information from the report because we don't understand it"-situation.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
Matthew D. Hoedeman over 1 year ago in reply to R2ah1ze1l

vpt.se, it is a legacy report, 'datum shift' is fubar in legacy.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel