Reporting with dashes between datums

[Liam_1968]

I am trying to write a CMM report reflecting the information on the customer's drawing. The issue is I cannot get XactMeasure to report the GD&T displaying the datums with dashes between them, as shown in this drawing. Can anybody help please.GDT DATUM QUERY.jpg

[gibsonridge]

when you create your datum label use the underscore instead of a dash, (dash causes problems)

[Liam_1968]

Hi gibsonridge.

Thanks for the reply.

There are three datums defined on the drawing. A, B and C.
A is the master plane
B is the centre of the counterbore
C is the centre of the widest slot in Y

My issue is, that when creating my report, how do I call up | A | B-C | B | in PC Dmis as datums for reporting the true pos, form and location. PC Dmis does not give me the option

Thanks in advance.

[gibsonridge]

you should construct a line thru Band C / called B_C using this as your secondary in your alignment

[sealevel]

Compound datum needs to be made from CYLS or CIRS. Since you probably have used a midplane for the Dat C slot, use a generic CIR instead, then you should be good to go in Xact when typing in your B-C.

[brian.freeman]

You can create a compound datum; first create the DRF with the first datum then create; then insert a dash followed by the second datum.

 FCFLOC1 =POSITION : CIR_C
FEATCTRLFRAME/SHOWNOMS=NO,SHOWPARAMS=NO,SHOWEXPANDED=NO,
SIZE TOLERANCES/1,DIAMETER,0.205,0.004,0.003
PRIMARY DIMENSION/POSITION,DIAMETER,0.084,MMC,D,A,[COLOR=#e74c3c]B-E[/COLOR]
NOTE/FCFLOC1
FEATURES/CIR_C,,

[Liam_1968]

Thanks all

Hi sealevel
I have constructed the generic circle where my slot midplane is. Called the generic circle datum C.
When I come to report the true position of the end face (just started there as an example), I can not type in the B-C datum callout in Xact.
I can only use my A and B datums, the go into the program (the edit window) and type over the B datum with B-C, then add a B callout later.
I then get an error as shown in the image

DRF Error.jpg

So, now my report reflects the customer drawing, but it reports that the end face is a country mile out. I am programming offline with nominal CAD.

Report Error.jpg
Measuring the end face in position only, I get the correct result

DIM LOC1= LOCATION OF PLANE RGHT_END UNITS=MM ,$
GRAPH=OFF TEXT=OFF MULT=10.00 OUTPUT=BOTH HALF ANGLE=NO
AX NOMINAL +TOL -TOL MEAS DEV OUTTOL
X 275.500 0.001 0.001 275.500 0.000 0.000 ----#----
END OF DIMENSION LOC1

Sorry to be a pain, but any help would be greatly appreciated.

[Liam_1968]

Also, when I try reporting TP using just datums A and B I get the correct result

AB Only.jpg

[pernilla]

I would've guessed that B-C should be a line between datums B and C. Which would mean you get plane, line, point in the datum system A, B-C, B.

[RandomJerk]

The FCF is redundant. Normally a dashed datum should indicate things that are coaxial where the two datums are non continuous features that may or may not be the same size.

In this case, |A|B|C| accomplishes the same thing the horror your FCF thinks it does - A controls one axis and sets the origin, B alone creates the origin of the other two axis, leaving nothing but the final rotation, controlled by C.

[RanDawgg]

Exactly. This is a goofy drawing all-around. The longer I look at it, the worse it gets.

[KIRBSTER269]

Just now reading this. I was looking at the drawing above and was saying to myself, there is NOT 1 callout that says A|B|C, So I'm with RandomJerk here.

A=PLANE, LEVEL and ORIGIN Z
B-C = (CONSTRUCTED) LINE (from B to C) ROTATION ONLY
B=CYLINDER OR CIRCLE, ORIGIN X and Y