Measuring measured items don't agree

[Eric Milberger]

I measured between wall - then I measured the measurement

AND they are 1" different????  HELP Please as this is not a good start

[Eric Milberger]

I did make sure that I had no fractions in my setup.

[Rajesh Patil]

Are you trying to compare between the background CAD file and Archicad drawn elements? Is the background file is image or CAD file attached as Xref?

[Eric Milberger]

NO

The background is there but I am comparing two dimensions.

The first string is snapped ot the walls placed in Archicad

The 2nd wall measures the string of dimensions.  

The 2nd string of dimensions add up to 1" more that the measurement from the start to the finish of the first string

This happens on all my long strings of dimensions

[Barry Kelly]

Change your dimension settings to show as much decimal accuracy as you can.

You will probably find the walls are each a fraction less than they show - so they will be rounding up to the values you see due to your settings.

But when measuring the overall, there are enough fractional errors to make that one dimension round down to what you see.

i.e. 10' 1¾" will round up to 10' 2"

But 10' 1¾" + 10' 1¾" + 10' 1¾" will round down to 30' 5" (actually 30' 5¼").

Barry.

[Richard Morrison]

This is clearly due to rounding error. Best practice is to input walls and other entities based on exact dimensions, rather than relying on a dimension display. (What is displaying in the tracker may be 1'-4", when you are actually drawing 1'-3 5/8" because you've turned on display fractions to the nearest inch, say.)

[Eric Milberger]

Yes, the items are drawn real but only need nominal dimensions to layout walls.  Plus this is an existing building.  Struggling to make this work easily without fractions as  they are of no benefit.  Nominal dimensions are perfect for the plan with actual perfect for the detail.  

[Richard Morrison]

Accuracy is always a benefit. Giving contractors unachievable accuracy in dimensions is not. However, in laying out walls, any decent contractor should be able to build to at least the nearest 1/2" without breaking a sweat.

[Eric Milberger]

We always dimension to one side of the wall.  To snap a chaulk line only requires one. And I measure to the same side of a wall unless there is that rarity where a fraction of an inch would cause an issue.

Then it avoids anyone from adding and subTracking fractions on a job.

I remember the days when I’d find a good contractor or staff who struggled or could not read.

But just simpler to layout without fractions.