ArchiCAD to DWG - scale error

[BoldArch]

We have published a series of drawings for our client in both PDF and DWG formats. We have been informed by one of the recipients that there is a scale issue with the DWG files.

The issue seems to be that if we have a 1:500 drawing published to DWG from ArchiCAD, in AutoCAD the "model" is scaled at 1:500. This is to say that if you use the measure tool in AutoCAD, the measured value reads as if the model is drawn to a 1:500 scale. Have attached an image that shows a 50,000mm long segment of boundary modelled in ArchiCAD, measuring at 100mm in AutoCAD.

I have little experience with AutoCAD, but I would assume this is a major issue that we need to solve on the ArchiCAD output end. I would have thought the AutoCAD model space should read at 1:1 scale (as ArchiCAD's model space does), and the drawings be scaled appropriately to fit the required sheet size.

Is this an issue anyone else has come across? Is there something in ArchiCADs translators or export settings that we are getting wrong? Having been notified of this issue, we have reviewed other published DWG files and have realised this issue has occurred for years across many versions of ArchiCAD. Can only assume recipients such as engineers and surveyors have scaled the DWGs on import to suit. We can not expect the same of a client.

[Srinivas]

Namaste,
I believe you are measuring the dimensions on AutoCAD Layouts instead of Model space and hence the error. To get the correct measurement navigate to the model space and measure.
Hope this helps.

[BoldArch]

Thank you for the reply Srinivas, but can confirm this is not the case. Measurements are being taken from the model space in AutoCAD.

[Minh Nguyen]

Hello,

Thank you very much for the question!

Assuming that you publish a layout to DWG, there are a few ways how it is created in a DWG file:



With the option: Save Layout into: Model space, the layout is drawn into the Model Space. With this method, the scale of the elements is the scale of the Saved View.

With the option: Save Layout into: Paper space with ... content, the layout is drawn into the Paper Space, with a real model placed in the Model space as reference.

With the option: Save Layout into: Paper space with Drawings as Blocks, the layout is drawn into the Paper Space, and all the drawings are converted into blocks in Paper space. Thus, the scale of the view remains in the paper space.

Depending on the translator, it may affect the length of elements in DWG. I'm wondering if this is the case?
Looking forward to hearing from you!

Best regards,
Minh

[BoldArch]

Hi Minh,

Thank you for the reply.  Sorry I have only seen it now.

After testing with the info you provided, I believe the "Save Layout into Paper Space with cropped view's content" is the option we want.  This way the items in the "layout space" are scaled as per the drawing's scale, but elements in the "model space" are drawn at a 1:1 scale.

My question is - what defines how much of the model is shown in the "model space" in AutoCAD? It does not seem to relate to the extent of the cropped view - it seems to be a random cropping extent. Would love to know how to control that extent.

Appreciate your help,

[Roopa A]

I am also having the same problem.

Tried the above methods too.

Please help us...