what variable controls this (dimensions tolerance )?

[mrkaplan]

attached a drawing with two dimensions

what variable controls the  difference btw the two  ?  thanks 

[Kent1Cooper]

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@mrkaplan wrote:

attached a drawing with two dimensions

what variable controls the  difference btw the two  ?  thanks 

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There seems to be a problem with the drawing file, but look at the following System Variables:
DIMLIM

DIMTFAC

DIMTM

DIMTOL

DIMTOLJ

DIMTP

DIMTZIN

Also look into the Tolerances category in the Properties box with a dimension selected.

[mrkaplan]

what problem ? were you unable to open it ?

i am looking for what variable controls symmetrical tolerance display deviation vs symmetrical

see attached pdf

[mrkaplan]

here is the result of some experimentation

i create a dimension style with a symmetrical tolerance . i make two identical dimensions .

Using properties , i change dimension #2 to deviation .

i list it  and here are the overrides : 

 DIMGAP      0.6250
 DIMLIM      Off
 DIMTM       1.0000
 DIMTOL      On

 i then apply these overrides using DIMOVERRIDE to dimension #1

dimension #1 stays the same  ( symmetrical ) 

what to make of this ?

[Kent1Cooper · Accepted solution]

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@mrkaplan wrote:

what problem ? were you unable to open it ?

i am looking for what variable controls symmetrical tolerance display deviation vs symmetrical

....

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[When I first tried, I couldn't open it, but got a corrupted-file message and the suggestion to try Recover, which didn't work either.  Nor did TrueView succeed in getting into it.  But now I just tried again, and it worked.]

I haven't been able to find a way through System Variables to get the stacked deviation style when the values are equal, except via fooling it by, for example, setting DIMTP to 1 and DIMTM to something off by less than the rounding value, like 1.0001.  So on a lark, I did this in your drawing, without having changed anything:

Command: (rtos (getvar 'dimtm) 2 10)
"1.000000001"

Command: (rtos (getvar 'dimtp) 2 10)
"1"

So the deviation style with apparently equal values is resulting from the two values actually being different, though by far less than the rounding value for either drawn dimensions or value display in the Properties box or Command: line.

[mrkaplan]

thanks for your input . i might use that in a lisp and for instance add  0.000001 to DIMTM   
as i understand,  autocad doesnt really tell us what it does when it changes from symmetrical to deviation

[Kent1Cooper]

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@mrkaplan wrote:

....   
as i understand,  autocad doesnt really tell us what it does when it changes from symmetrical to deviation

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Check out the ToleranceDisplay VLA Property: 1 for Symmetrical, 2 for Deviation.

Changing a Symmetrical-toleranced Dimension to Deviation in the Properties box changes that property and the display, even when the + and - values are equal.  Whether you can force it to be 2 for new Dimensions when the settings are equal, I'm not sure, but you should at least be able to force it once a Dimension is drawn, with one of the VLA "put" functions.