Units issue: Importing millimeter block into meter file

Rhino
1

Hi,

we draw files in Meters, but receive Block data from external companies that is drawn in acad/millimeter.

How can I import these millimeter blocks into a meter file so that stuff displays correctly w/o going trough some tedious prcoess of adjusting all dimensions/text/radial dimensions etc. manually?

thanks,
Daniel

2

Normally, if Rhino detects that a millimeter file is being imported into a meters file, it will scale the incoming file accordingly. However, if you are importing stuff directly from AutoCAD via dwg/dxf, I am not sure the information is in the ACAD file in a way that Rhino can detect and act on it.

You can try by exporting a block in mm from Rhino as a .3dm and then importing it into a Rhino file in meters, the scaling of geometry will be correct. In experimenting with exporting a mm block from Rhino via .dxf and then re-importing it into a meters file, I see the automatic scaling does not work at all.

Concerning text blocks, leaders, dimensions etc. as far as my experience goes the dimension styles are never correctly imported…

3

thanks!

i see… yes saving as .3dm helps with displaying the dimensions/text/leaders correct, graphically. But units will still be off, and adjusted manually.

I wish there would be a way to quickly import different unit blocks “WYSIWYG”

As you noted, some things seem to remain esoteric and not easy to fix:

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4

Here the dimension style (using the same size criteria) looks the same, and the dimension numbers are scaled correctly.

MM file

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Block, exported as .3dm and imported into meters file:

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5

Hi @dk2079,

When you place your block instance into your meters-based file you will get a DXF import dialog box. All you need to do is change the model units there from meters to millimeters and your millimeter-based block will play nicely with your model.

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HTH
Jeremy

EDIT: Explanation: Rhino doesn’t know what the unit of dimension is in the DXF file, so it proposes a default for the model unit in the import the same as the model unit in the destination document. You, knowing better, can override this. If your document used inches, Rhino would have proposed inches.