Export to AutoCAD scaling

Hi the title says it all.
When I export 2d line drawings to AutoCAD the scale is always way out of scale.
Any quick for this?

Thank you in advance.
Erik

If your Rhino file is setup at the correct 1:1 scale and unit settings, then it should open in AutoCAD correctly.

It might be better to set up an AutoCAD file using the same unit settings then Import the Rhino generated file into AutoCAD.

My guess is the AutoCAD “decimal” (unitless) setup is getting in the way.

Thank you John for your reply.

Strangely enough, I am normally importing Rhino 2D plans into pre-existing CAD plans where the units are already set up.
I will try again.

Also, can the command show lineweights in top model view in Rhino or does it have to be in layout?

Thank you in advance.

Hi Erik,
Here is the issue that I have seen.
When you export a DWG from Rhino that has a Rhino unit of Feet and open the DWG in AutoCAD, the model opens in Decimal units. In AutoCAD if you change the unit to Arch or insert into an existing model set to Architectural units, you get the model in inches. So instead of 20’ you now have 1’8". You can correct this by scaling the model by 12 to be equivalent.

AutoCAD’s Insert scale field is set to Feet correctly, but that is only used when inserting block from DesignCenter, but it does not affect the size of imported geometry.

I would appreciate seeing a 3DM and the exported DWG to see if there is an problem with Rhino.
One thing to point out, Rhino allow the model to have a base unit set to something other then inches, like feet, miles …angstroms. :smile: AutoCAD does not. AutoCAD has Architectural which has a base unit of inches, or it has Decimal, which is anything you want.

If you prefer, you can send me the file directly, mary@mcneel.com.
Then I can look at exactly what the issue is.

To show the print weights assigned to layer or objects in Rhino, use the PrintDisplay command. Turn it On.

Sincerely,
Mary Ann Fugier

Hi Mary,

Thank you for your reply. It is strange that AutoCAD works like that, but I have figured a workaround in the past by having two windows of CAD opened, importing into the blank one, and then copying into the working file.

As for the current 3dm I can send something, but I am mainly referring to my previous problems I encountered nearly every time I collaborated with CAD workers. I actually just got a call from the metal factory (who opened my exported .DWG file and had no complaints) so I think that things are fine when importing into a blank document. I will need to check on how the interoperability works with your information.

Thank you again and have a nice weekend.
Erik

Hello,

I am now having difficulty importing a .DWG into Rhino where the scaling is greatly increased once imported. For instance I imported a floor plan that was supposed to be 40feet wide and it came in at 270feet wide. Attached is a snapshot of my import settings. I also tried layout as ‘feet’ as well to no avail.

Thank you in advance for your responses,

Erik

Brobes,

Set the AC and Rhino units to inch.

Thanks KevJin for the reply,

That works perfectly for the linework, but for the blocks and dimensions they are still coming in large. It’s certainly a start though! Any ideas on how to mitigate the block and dimension scaling issues?

Thank you in advance,
Erik

If you get those blocks on the internet, most likely they are not scaled. I think there is no way to scale them automatically since block unites aren’t always feet/inch. In other words, if your block original unit is either mm/dm/cm, you will have to convert them to feet/inch. A lot work to do in that way…plus if you try to scale them to fit building codes, there’s even more work to do.

Where do you get those blocks? I remember I downloaded them from revitcity.com and some other random webs which I guess you know more than I do…

KevJin is right. Set your units to Inch in Rhino and Fractional in AC and then it’s basically a one unit to one unit conversion. Can’t comment on the blocks though without seeing them.