Hi Paul, check out Tom Meeks' blog here:
http://cubifyfans.blogspot.com/ - try going back way to the start of his blog there and watching some of the videos that he put up when he first got his Cube 3D printer, he explains a whole lot of stuff and shows it in action with various kinds of tests.
> For example, I've seen things like chains or rings linked together that were 3D printed. How can
> they "print" objects that aren't connected, yet are intertwined?
They're able to do this just by the nature of building objects in a thin "layer by layer" method. There are also some kinds of "support structures" that get built up as part of the process which get taken out at the end, I think Tom has some of those in some of his videos so you can get an idea of some of the other things that are happening during the build process.
> Also, how do you figure out what size to make the object?
Well, it's totally up to you, it can be whatever size you decide you want to make it... But most 3D printers are primarily focused on objects not all that large something like 3 to 5 inches across or so.
There are quite a bunch of different types of 3D printing methods though each of which has different things it can do.
> I've read that you need to make sure your object is seamless
Yeah your object has to be a solid, not just a surface that has open edges around it. In MoI there is an "object type indicator" that shows in the upper-right corner of the screen that tells you some information about your object, when your object is a solid it will read as an object type of "Solid" being displayed there when your object is selected.
Then the typical way to transfer data to a 3D printer is to export to STL format which will make triangulated data. Then each printer has some software that it uses to read in the STL file and calculate sliced up sections, and the printer deals with one sliced up section at a time to build up the result.
But anyway Tom has a whole bunch of nice introductory videos especially earlier in his blog where he's showing the basic operation of the machine, which I think would help you a lot.
- Michael