An open source 3D printer has different designs, and some are simple. This normally require fewer materials than most of other 3D printers. It has a frame that can be made from a single 4’ long or longer, and about a 2 and an half square tube, then 14 guage/1.5mm/about .0598, and it is very cheap. This is a design that has fewer plastic parts, and still build a structure that is stronger. It has wires, but they are all hidden. Some people finds the finishing of a unit to be more appealing, after it is finished.
There is a simple and 3D printing program that has open source. This is the kind of software that will drive the MakerBot Replicator, CupCake, Thing-O-Matic, RepRap machine CNC or even a CNC machine that is generic. It is possible to either give it GCode or STL file that it can process, and it will take it from there. It has a cross platform that can easily be installed. It is also based on familiar processing environments. There are thousands of MakerBot operators that use ReplicatorG. This make it possible for them to print tens of thousands of 3D objects, and the number is still increasing.