MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I made mine with ABS, It was easy to "weld" together and smooth. Most of the parts I designed should be small enough to not warp, but some of then do have some issues. It's not really that big a deal in the big picture, as filler of some kind is needed to fill the cracks. PLA can't be welded very well. Most two part epoxies wont work well, and it's more brittle. Check out Instructables for Vacuum forming machines. Very simple to make and well worth it for other projects.