You can find programs, such as the Babel3D, that can export a 3D CAD data saved inside a 3D PDF document and save it in one of the CAD/3D formats, including the STL format which is used for stereolithography - 3D printing.
Convert Adobe Portable document format to Stereolithography CAD file.
We have found 2 software records in our database eligible for .pdf to .stl file format conversion.
On-line services software - convert pdf to stl on web
A commercial online CAD converter
Convert from pdf file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned pdf to stl. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
An online CAD conversion service