Expert: Shauna Anderson - 9/5/2011

Question
I just started a job that requires me to use AutoCAD.  I did my first drawing there Friday and there were two dimensions that were off. One was off by .001 inches and the other was off by .01 inches.  I struggled to learn to use the length command to shorten the lines in my drawing and fix these dimensions.  I could not master it.  I told the employee charged with training me my problem.  He had me explode the one of the dimensions and alter it to read correctly.  The other problem he said “was just the way AutoCAD is.”  After lunch a third dimension was found to be off by .04 inches.  I was able to master the lengthen command by then and fixed this third problem.  I shortened some lines and moved some stuff to correct the drawing and the dimension became correct.  I offered to fix the first two problem dimensions the same way but the employee said it would not be necessary.  I do not want to lose this job.  Should I insist that I be allowed to fix those first two problem dimensions?  What should I do in the future about this sort of thing.  Is the lengthen command my only option?  Should I try dimensioning my drawing as I draw it instead of after I have finished drawing everything?  Please advise.
I learned how to use the stretch function this weekend just in case.

Answer
LENGTHEN is an alternative to extend and trim. So by using it to fix the dimension, I think you were actually correcting the length of the geometry.
The comment about it being "the way ACAD is" is said when a person does not know the answer. I usually say, "because it is ACAD and can do what it wants."  The truth is AutoCAD is incredibly accurate and will do just what it is told. Granted that is not always what we wanted.

So let's try to figure out what the problem is...

First most obvious - the geometry is incorrect. This would seem to bear out since lengthening the object adjusted the dimension to the correct dimension. If they need to be accurate to these small numbers be sure the drawing is correct. Since it was off by .01 and .001, please check your units - guessing they are decimal. Select 8 decimal point accuracy and go look at it all again. You may as well turn on high decimal point accuracy on your angles too - just for kicks - are the lines truly straight? You can lose length in a barely crooked line.

If the geometry is beautiful, then check the accuracy of the dimension style. If it is set to round at 2 decimal spaces, your .016 will be .02, etc.

In my opinion, accuracy will definitely help you keep the job! Should you insist on fixing the other? Depends on who you are talking to, but I would approach them with "that ACAD thing is unsettling, I'd like to dig a little deeper - even on break"  then you get a chance to make it right.

If it comes to a choice, I am in favor of accurate geometry and overriding dimension text. That is opposed to fake geometry to get the dimension to read right. Neither of those should have to happen though. You may have found the problem (something in their own setup) that everyone else knows is there and just works around.

If you don't think I have answered this satisfactorily, please feel free to write back. Good Luck!!

-Shauna