Just go to this link, then click Browse, select your PDF file then enter your email address.

You may have to dodge a few ads in the resulting email, but the actual DWG output is fast and the quality is not too bad.

I have posted about extracting useful data from PDFs before:
Obtain Vector Information from PDFs using Free Tools

Or if you want to convert an image to a DWG file:
Converting a raster image to a DWG file

I wanted to convert a PDF file into content I could use in a Planting family in Revit.  Part of that process involved converting the image into DWG hatches that Revit could understand, either as an import or as a Filled Region.

Here is the process (scroll down for video):

  1. Download Adobe Illustrator
  2. Open the image in Illustrator.
  3. Select the image
  4. Click the ‘Live Trace’ button in the bar at the top.  There are a number of different methods to choose from.  The most accurate seems to be ‘Photo High Fidelity’, but this will likely result in the largest DWG.
  5. Save the file in Illustrator.
  6. Click File – Export and save as a DWG!

 Here is the video:

You may be unfortunate enough to have to translate a BIM model from ArchiCAD into Revit. I have done this in the past (with limited success) using IFC.

However, I was browsing the AUGI Forums today and came across this post, which recommended the use of Solibri IFC Optimizer. This is a free Java utility that launches from your browser (you do need to register first). You then feed your IFC file into it, and it, well, optimizes the file.

I gave it a go and it reduced an IFC I recently worked on from 21.6 mb to 13.7 mb – so it actually does work.

Check it out if you are using IFC…