Bill Landskroener from the US very kindly took the trouble to write in with a new link from which you can download OttoPDF – a stand-along freeware utility that converts AutoCAD drawings to PDF files. The developer pulled the plug on the app and downloads were hard to find. Now, thanks to Bill, you have one.
There is a site search available but it didn’t work when I tried so you’ll have to go to the Utilities section and then to the Conversion sub-section and then hunt through the pages therein.
To know more about OttoPDF, check the PDF Utilities section.