Page Setup Scale when changing Units

[Mitrovski95]

I have a template that is in mm that I would like to convert to cm. While the template was still in mm just as a test i drew a 5000x5000mm square. At a scale of 1:50 this should plot as 10cm. I'm plotting from layout so in page setup I created an A3 sheet and I set the scale as 1:1 (1mm = 1 unit). I set the viewport annotation scale as 1:50 and it plots correctly. When I measured the paper size using DIST it measures correctly at 420x297mm.Then I used -dwgunits to change to cm with these settings:

1. Drawing units >4
2. Drawing unit display formats >2
3. Linear display format >2
4. Linear display precision > 2
5. Scale objects from other drawings upon insert? >yes
6. Match INSUNITS to drawing units? >yes
7. Scale objects in current drawing to reflect change in units?> yes
8. Include objects in Paper Space? >yes

The paper size doesn't change to 42x29.7 but it remains 420x297. When i go to plot settings the scale automatically changes to 1:10 but it still says 1mm = 1 unit (there is no option for cm, just mm and inches). With this setting everything plots correctly, but shouldn't the scale be set as 1:1 and set to 1:50 via the annotation scale in the viewport? So when I set page setup scale to 1:1 i get 1mm = 0.1 units (which i guess i correct as 1mm=0.1cm) but then the viewport becomes too big and doesn't fit on the paper and when i set the annotation scale to 1:50 it doesn't print at the correct scale.  I uploaded a short video of the process on youtube, perhaps it will show better what I mean: https://youtu.be/34qQI4eYKrM 

I'm not sure what the final option under -dwgunits does (include object in paper space) but i tried it with NO as well and I get the same problem. I'm just trying to better understand how the plotting scales work.

Any help would be appreciated.

[jayhar · Accepted solution]

AutoCAD doesn’t really work in centimeters when it comes to plotting – plotters only understand mm or inches. That’s why your A3 sheet still shows as 420×297 mm, even after switching units. You don’t need to worry about the plot scale numbers, because the output is still correct. And for the -DWGUNITS option “Include objects in Paper Space,” it’s better to keep that set to No, since paper space already represents real paper sizes in mm and you don’t want your title block or layout items to get stretched.