Issue changing units to metric

[Anonymous]

Hi all, 

I'm a complete AutoCAD novice. I'm currently practicing with a trial version of AutoCAD Architecture 2020 and I'm on a Mac. I need to be working in metric (centimetres or metres). I type "UN" into my command bar at the beginning of my drawing and change the insertion scale units to millimetres. When I then start my drawing, the info displayed in the dynamic input is showing in feet and inches. Should this not change to mm? I've attached a screenshot.

Likewise when I draw, I'm not convinced that the units are in millimetres. This might sound like a really basic way of checking, but I've created some shapes and applied an offset to each shape. I've saved this, created a new drawing and done exactly the same thing but in metres instead of centimetres. I've not zoomed in or out, but the size of the shapes and the offset dimensions appear the same in each drawing.

Is there something else I need to be changing to get the units I need?

Thanks on advance!

[David_W_Koch]

@Anonymous 

Welcome to the community!

Are you running AutoCAD on the Mac OS?  If so, you are running AutoCAD, not AutoCAD Architecture, which is only available for Windows.  If you are using Bootcamp or Parallels to run Windows on your Mac, and are running AutoCAD there, it could be AutoCAD Architecture.  Do you see something like this when you type UN and press ENTER?

Perhaps the Length type is set to Architectural, rather than decimal, if you are seeing feet and inches in the dynamic input.  Best practice would be to set your default template to one that has your desired units settings so that new drawings are set the way you want from the start.  If you have a drawing file that was started with an imperial template (MEASUREMENT System Variable set to 0, insertion units set to inches (or, possibly, feet), Length Type set to Architectural or Engineering), to make it metric, you will want to change the MEASUREMENT System Variable to 1 (so that the ACADISO.lin and ACADISO.pat files are used, rather than ACAD.lin and ACAD.pat), insertion units to the desired metric unit (Millimeters, Centimeters, Meters) and the Length Type to Decimal, to avoid seeing lengths expressed in feet and inches.

AutoCAD is, for the most part, unit agnostic.  One unit can be anything you want.  The Units to scale inserted content setting only comes into play when inserting content from another file.  If you set the units to decimal, and draw a 3-unit by 4-unit rectangle, and then offset it by 0.5 units in two separate drawings, one set to Meters for insertion unit scaling and the other set to Centimeters, and then zoom to extents, on screen the two files will look identical.  Only if you try to insert the Centimeter file into the Meter file (or vice versa) will you see that the Centimeter rectangles are smaller than the Meter rectangles, and that only because the inserted content was scaled to account for the difference in the stated insertion scales.

In AutoCAD Architecture, you are actually setting a unit for the units value, and if you change that, you will be asked if you want to want to rescale model and paper space objects, model space objects only or do no scaling.  Changing the units from Inches (with Architectural Length Type) to Millimeters will automatically change the Length Type to Decimal and you will no longer be offered Architectural or Engineering as Length Types.  And, when typing UN and pressing ENTER, instead of the Drawing Units dialog, you will get the Units tab of the Drawing Setup dialog, which looks like this: