A set of parametric OpenSCAD scripts that generate ready-to-print two-part molds from arbitrary STL models.
These scripts can be used to generate either square (with or without rounded corners) or circular two-part molds and are fully parameterized to make it easy to adapt for your application.
Refer to the instructions below for some general tips, as well ideas for casting.
I have successfully made casts from these molds using wax, Knox gelatin, Oogoo and chocolate. If you have success with other casting media, please leave a comment!
Many more pictures of molds and castings I made with these scripts: http://www.flickr.com/photos/zenwebb/collections/72157631531182783/
If you'd like to read about the development process for these scripts, and learn from some of the issues I came across, check out:
If you really want to bring your molds and castings to the next level you can even try the "lost ABS" (or lost PLA) process to turn it into metal!
I have also uploaded a parametric open-face mold generator to create positive and negative molds.