Many 3D printers are established on the market. But there is one that is among cheapest, which is the Flashforge Creator. This is basically a 3D printer using a device that is computer-driven, and make objects out of the materials that have been supplied by its user.
This type of printer is the kind that melt plastic with heater and then pushes liquid plastic out of a metal nozzle to a place, where that melted plastic would quickly be hardened into something solid, which partially prepares it for moving ahead in the process of making the three dimensional object.
Further, the printer will then builds up that hardened plastic one layer after the other to create the solid objects. This is a process that is completely under the computer control, which makes it possible to say that any imaginable shape is possible for creation. This kind of printing is known as FDM or the Fused Deposition Modeling. There are still other 3D printers that make use of either liquids or powder, and use either spray or lasers, for fusing all materials together.
This is a technology that is controlled by the imagination and designing skills, because anything designed in the digital file can be printed with the FDM.