Angular Dimension tool gives discrepant results

[EscottS]

Hello all

I'm having an issue with my Angular Dimension tool. I've put down some polar guide lines and I'm trying to get a part lined up 90 degrees relative to the Y axis. DIMANG says that it's at 90, but my eyes and my other measurements say otherwise. 

Any ideas what might be causing this discrepancy? I've attatched a .dwg illustrating the problem.

Thanks for any help!

[doben]

The problem is the white lines are slightly off horizontal. The angular dimension is showing 90 degrees because the precision is set to degrees only. Open the Dimension Style Manager and change the precision to d-m-s and you will see the angle is actually 89d40'09". 

[nestly2 · Accepted solution]

In your drawing, both UNITS and DIMSTYLE are set to round off to the nearest full angular unit.  When using those settings, even if a line a 1/2 a degree out of plumb/level, AutoCAD will still report it as being plumb/level.   Your object is rotated about 0.33 degrees, but because you have the angular precision set so low, the dimension is still rounded to 0.

Just to be clear, changing the "Precision" in UNITS and/or DIMSTYLE does not change the accuracy of AutoCAD.  The "Precision" is the level of rounding  you're telling AutoCAD to preform when showing you measurements..

Animation below shows how to increase the dimstyle precision, and also how to rotate the object so it's at 0.00000000 degrees.

[EscottS]

Thank you very much, this is incredibly helpful!