Setting the right scale from AutoCAD

[Felipe...@adobeforums.com]

I have to import several drawings separately from AutoCAD. The problem comes when I bring them to Illustrator CS2: the drawing seems to come in a different scale, wheter I center the drawing or not. Is there a method to have the correct scale when importing the .dwg files?

Thanks,

Felipe Ribeiro Cunha
Architect

[ti...@adobeforums.com]

not sure... but i use cadtools (www.hotdoor.com) to get acad files to scale in illo. just a scale factor basically.

you could do the same in illo without cadtools.

[Felipe...@adobeforums.com]

The problem is that I have to measure the lines in illustrator, and apply a scale factor manually to each drawing (.dwg). Illustrator imports them sometimes with different scale factors, so as I am assembling various drawings in one illustrator, I have to know what's the scale of each of them...
Just to save time...
Thanks anyway

[stan_ala...@adobeforums.com]

Felipe,

The easiest way I've found to get AutoCAD files into Illy with the proper scale is to make pdfs from AutoCAD. Then, your line weights stay as they should and the drawing opens at the proper size and scale. I've got a good system going using this method.

Stan

[Ben_M...@adobeforums.com]

See <http://www.adobe.com/support/techdocs/325101.html> for an explanation of why this happens

[Jacob...@adobeforums.com]

Should it not be 3.93701 percent?

[stan_ala...@adobeforums.com]

This solution still doesn't solve the problem of line weights. When opening a dwg or dxf in Illy, all line weights are equal. A pdf preserves the line weights.

[Pieter_d...@adobeforums.com]

it should be 3.937007874015750000 percent, to be exact ;)
(1 / 0.254 )

I'm having the same promblem. Some drawings are imported (from Autocad 2k6/7 to Illustrator CS2, on winXPsp2) in the right scale, but some are scaled down (with the above factor)
IMHO it seems to be a problem (techdoc 325101) inside the DWG-file, wether it has units defined or not. I guess Illustrator (or the DWG itself) use inches by default if the units are not defined.

Right now I'm trying to 'convince' my DWG's to assume meters at all times .. I'll post a 'how to' as soon as I've figured how to do this ;)

[simone_...@adobeforums.com]

If you save in autocad the DWG drawing in the layout tab (with the right scale)and the import in Illustrator, your draw will be in right size.

[Pieter_d...@adobeforums.com]

simone,

thanks for your advice. I tried, and it sort-of worked. I think my problem is the sheer size of the (acad) drawings ..

Mostly i'm working with (city)-maps. Fairly big drawings, in size and scale. (app. 5 by 7 kilometers, 1 unit = 1 meter in autocad)
I found there's some threshold/limit, because when I import these drawings partially (I cut off a piece and import it in Illustrator) it works fine, but as soon as the chunks get to big, and I'm not sure what the limits are exactly, Illustrator shrinks the drawing with a factor.
hmm.. I'll just start slicing up my maps then..

[stan_ala...@adobeforums.com]

Why won't any of you people try a pdf? I see no benefit to opening the dwg directly instead of a pdf from CAD. It opens the right scale and the line weights are correct.

[stan_ala...@adobeforums.com]

that's odd, how much is the scale off harron? I've never experienced that.

[Harron_K....@adobeforums.com]

I use the PDF method often. Line weights are fine, but the scale is always off, requiring a manual adjustment.

[stan_ala...@adobeforums.com]

I always look for dimensioned objects that will enable me to establish scale.

Indeed, but I figure if you have the dwg file and you know AutoCAD, why not scale in AutoCAD and plot to PDF therefore saving the hassle of dealing with it in Illustrator, not to mention the loss of line weights.

[Harron_K....@adobeforums.com]

I find myself changing line weights regardless of import method, so that's not an issue for me.

Some users object to the flattening to a single layer with PDF import. It doesn't make much difference to me, but, then again, I don't deal with extremely complicated drawings.

Finally, for me there is no loss of "scale" in the true sense of that term. If the drawing comes in at 36 percent of actual size, it is still to "scale." As long as there is some reference, it is really a non-issue for me. I guess my requirements are not that stringent.

All of that said, the PDF route is my favored import method, Stan. It has simply been more reliable with more drawings than opening directly in AI.

[Harron_K....@adobeforums.com]

It really depends on how the PDF was created, Stan. For example, in some CAD apps, one can "plot" the active screen view to PDF, and that magnification could be any value depending on the zoom factor.

[stan_ala...@adobeforums.com]

Yeah I see your point about layers. But because I depend on line weights so much, I prefer the pdf over the layered dwg. One way I've found to get around that is that when I want a certain item in the floor plan to be easily selectable, like say property lines, I make it a pen weight not used anywhere else in the CAD drawing. Then, in Illy I can select, similar, by line weight. Presto! I also force my text to go to a new font and true type so i can select it too.

[Chad_B...@adobeforums.com]

Stan,

I understand your recommendation to use PDFs. I use both methods for different needs: 1. AutoCAD to PDF to Illustrator 2. AutoCAD to Illustrator.

The problem with the PDF is that all the objects are on one layer, grouped (and not easily ungrouped), and doesn't contain logical objects anymore (a rectangle is just 4 lines, not a rectangle).

The advantage to opening dwgs into Illustrator is that the layers are retained along with the objects. This makes it much easier to render Layers by Appearance, etc.

Felipe,

For scale issues, some of my users have the CADtools plug-in by Hot Door. It works pretty good.

Users that don't have the plug-in usually setup the DWG in a layout tab in AutoCAD to a known scale and then put a rectangle of a known size at the outer limits of the drawing (example: 24"x36"). Then when you import the dwg into Illustrator select all. Using the Transform palette set the width and height to 24" x 36". Now all the objects in Illustrator are at the same scale as the layout sheet in AutoCAD.

It would be nice if Illustrator could read the layer information from a PDF that is exported from AutoCAD using the Acrobat Professional integration. Has anyone seen this work?