StL Format

From: Marshall Burns (Ennex  Corporation)
To: RP-ML
Date: Saturday, September 17, 1994
Subject: StL Format
Dear RP Community,
     Thank you to Andre and Gil for clarifying that the StL format is not secret, while the "sli" (slice) format is. The StL specification published in "Automated Fabrication" is taken from a 3D Systems document dated October 1989, which 3D Systems verified for me in late 1992 was current and was public information.
     I have checked the format specification as listed in "Automated Fabrication" (page 231) and as far as I can tell it is correct. Prof. Huang, perhaps you can tell us more about the kind of error messages you are receiving from Partman to discern the source of your difficulty. On the other hand, if you have found the problem, it may be helpful to other users if you would explain what it was and how you solved it.
     Regarding Elaine's questions about the utility of the StL format and the need for better software development for autofab (or "rapid prototyping"), my answer is that yes, we definitely need a much better data format, and we definitely need much better user interfaces and data tools. Software development is underway and, as Elaine knows, these things take time. Cubital was one of the first to come up with an integrated user interface, their "Data Front End." In time, we will be seeing further improvements from Clemson, Materialize, Solid Concepts, Brock Rooney, Autodesk, and other names not currently known in the industry. The industry is definitely not happy with StL. For those of you who have "Automated Fabrication," you can find a discussion of some industry complaints against it and some proposed alternatives on page 222 to 224.