Exporting DWGs with multiple scales

[aral_jm]

Whenever I export from Vectorworks 11.5 to DWG format, the information exports cleanly, yet layers using different scales show up at different sizes when the DWG is opened in AutoCad. I have the 'Rescale layers to 1:X' turned off. Is there another problem I'm missing? I have also tried it with the rescale function on, in case I have absolutely no clue, but to no avail. Please don't tell me that I can only export one scale!?

Thanks!

[jan15]

Actually, you can't even export to one scale, unless you want to consider 1:1 a "scale". Autocad doesn't support the idea of scale drawings, so it's impossible to create a DWG file with any scale other than 1:1.

Since you can only draw at 1:1 scale in Autocad, there are two ways to reconcile that with the size of a sheet of plotter paper. There's an old way and a new way.

The old way, which I call that because it used to be the only way, was to make a title block that's, say, 96 feet by 144 feet, and fit all that to a 24" x 36" print (assuming you want to print out at 1/4" scale). Under that system, if you wanted to include details at 3/4" scale on the same sheet, you had to draw them 3 times as large as they really are, or at least re-size them to that size before printing. In the 1/4" scale drawing, you have to make the letters in your text objects about 6" high so they'll print out at 1/8" high. In the 3/4" scale drawing, you have to make the letters about 18" high. Dimensions, arrowheads, hatches and dash styles all have to be adjusted similarly. It's a masochist's paradise.

The new way has been available for 15 or 20 years, but many people still don't use it and/or can't understand it. It uses the concept of a giant "modelspace", where you draw the building at actual size, and a much smaller "paperspace", where you draw a 24" x 36" title block at actual size, and where for each drawing you create a viewport, i.e. a hole in that 24 x 36 paperspace through which you can look at a part of modelspace, zooming in as much as necessary so that part of modelspace appears at the right scale. You still have to make all the same calculations for text, etc (6" high letters and 8" long arrowheads for 1/4" scale, 3 times as large for 3/4" scale), but at least you don't have to draw a 2x4 as a 6x12, and 5/8" plywood as 1 7/8" thick.

The VW export facility can accomodate either Autocad system. It has to export to 1:1 scale, but it can either export everything at the correct size, as per the new system, or it can favor one scale and distort the others, as per the old. You could ask the Autocad users which they prefer. Personally, I would always assume the new system, exporting everything its correct size, with no re-sizing. The New Believers can create the necessary viewports for print-out, and the Old Believers can re-size the detail drawings for print-out. In both cases, it's the same as they do with their own drawings.