use drawing scale factor for standard Cad and civil commands

[amyyoyo1]

Hi, I am trying to figure out a way that I can use the drawing scale factor for standard Cad and civil commands like lines , polylines, circle, offset rectangles, lengthen, and arc.

It's there a way that I can set it up at the start up or there a system variable for it that I didn't know of?

[Neilw_05]

Autocad is unitless. It doesn't know if a line that is one unit long is 1 inch, one meter or one foot. The user has to tell Autocad what a unit represents by specifying it in the units setting. If you add a grid to ground scale factor into the mix it becomes inconsitent and prone to misinterpretation.

The only way to ensure consistency is to work in ONE unit specification per DWG. Map has the ability to perform coordinate system and unit transformations, but it does not support C3D objects, so if it is necessary to transform C3D projects to different coordinate systems or units, a strategy must be carefully planned BEFORE creating data.

I haven't read Richard Sincovec's articles but I understand Low Distortion Projections (LDP) and their use. In my opinion a project should be designed using ground coordinates, which may require developing a LDP system if the ground to grid scale factor is significant. Submitting the design models for integration into a GIS should be a low priority and can be achieved by transformations when the project is completed and ready for archiving.

So the workflow should be to set up the LDP and use it for all the design models. Any supplementary data and files provided by outside sources should also use the LDP if possible. Supplemental data that is in grid coordinates should be transformed to the LDP system for use in the project. If data needs to be modeled with different units (i.e. Architectural), those should be done in separate files and XREF'd using appropriate scale, offset and rotation parameters to make them fit the relative enviroment where they are used.

[mathewkol]

All the banter aside, to answer the OP's initial question; No, there is no setting where you can draft at a scale.

[amyyoyo1]

We draw all lines and entities in GRID coordinates and display values in Ground coordinate, and this create a problem when the line in fact is not the same length as the display values.

I am doing this for a survey company which super crazy over things like that. They want the two things to be match and they want to do it while drawing, so the user know they are not making any mistakes that they need to go back to fix it.

Thank you for all the inputs, but I have no choice on this matter. It has to be done this way.

[Neilw_05]

Can you draw your models in GRID units and then XREF them into another drawing with the Ground scale factor applied and annotate the linework there? Of course you won't be able to use Data References with that workflow but given the constraints you don't have many good options. At least this way you can draft without worrying about the scale factor.

[troma]

Another option is to use an expression with your scale factor in it within a line label. This way you can draw a line 100m long but label it as 80m.
If I was going this route I would have two components in the label: one that didn't plot and gave the actual length, one that does plot giving the scaled length.