Our goals were:
Keep in mind -- this is the "introductory" design intended to onboard newcomers to the project, so we're trying to make it as easy as possible to build. Once you've made this, you're ready to move on to more complex projects, like scanning, sample preparation, and more robust designs.
We haven't gotten all the way there on every goal -- we'd hoped to make a version that required no glue -- just locking tabs -- but we just couldn't keep it small enough to be printed on a folded-in-half letter sheet. See this note, this, and some of these photos for our process of integrating all these changes, and see this page for some of the many many people who've contributed -- most recently at a session at the Barnraising!