Created by Kevin Cole (Ubuntourist) <dc.loco@gmail.com> 2018.02.10
The PNG image was produced from HacDC-logo_only.svg included in the HacDC Logo GitHub repository.
The SVG states that the size is 1279 x 1361 units.
American passport booklets are roughly 125 mm * 87.5 mm. I'm arbitrarily deciding that a passport stamp should be no larger than 60 * 60 mm.
(The two stamps in my current passport are roughly 43 * 27.)
apt install imagemagick png23d sed openscad make
make clean
make all
Then edit the resulting SCAD file to add a base and text.
(A quick test can be made via make test which will produce an
STL without the base or text. This can be fed into cura to
preview the conversion.)