Opening a cm dxf entering cm in the two windows sees a brick as 0.22cm long

What is going on, I have been sent a .dxf file from Autocad by a friend, he is drawing up the same structure as myself.
I am working in inches, as it was built in inches, he is working in cm ( ! )
I open the file using Rhino V5, I leave the two boxes in options as centimetres, it opens, I measure a brick on its long side (I know those in use were 8.75inch) and dims have it as 0.22

So I try again, altering the two boxes (layout and model) to millimetres.

I select that and copy paste it into my project and I cant even see it, zoom selected and there it is, a fraction of a brick in size !

When sent a previous .dxf a day or two ago, I went Rhino>open file, entered inches and it came in somewhat smaller, I then repeated with centimetres and it came in same size as my structure. Once open I look in Properties: units centimetres, dim style iso-25 brick 21.5cm , (my maths says 8.4646inch)

Yet today its not doing that.
I have just realised why, this file for some reason he is working in metres !

Should not the dxf know the units of measurement in use and display that in the open dialog box ?

(Now to fathom out why bricks are 22cm and not 21cm !)


Nope. DXF’s are uniltess. So you will need to ‘guess’ on import what the .dxf file units are - Rhino will not detect them in reading the file.

Now wondering why I have received, or I am seeing , only a front and top view, does dxf only do that, I work in 3D so as we know we have all orthos available, autocad doesnt do 3D, so he is doing old school projection.
Maybe he has chosen to send me a partial puzzle, I dont have autocad so dont know what views is shows. I spoke to another friend into autocad, again making views using projection, no perspective window.
How would he get to me a side view, as well as top and front, ?

they all open on our ‘top’ view.


If he used AutoCAD LT, it only does 2D. But like in Rhino, it’s also possible to simply use it in 2D to make classic “drafting-style” drawings. You will need to ask the sender.

AutoCAD standard can do 3D and .dwg files can have 3D objects in them.