Modeling dimensions
You must know the maximum dimensions that the printer that you intend to use can print. If your object is too large, then you must break it down or find a larger printer. One printer may handle a volume of 10.16 x 10.16 x 10.16 cm (4 x 4 x 4 inches), another 22.86 x 25.4 x 17.78 cm (9 x 10 x 7 inches). A service may be able to do 100 x 45 x 25 cm (39 3/8 x 17 3/4 x 9 13/16 inches) in one material, but only 15 x 15 x 15 cm (5 15/16 x 5 15/16 x 5 15/16 inches) in another material. When you are planning your object, know what you will print it with. The links later in this chapter will help you figure out which printer(s) are big enough to make what you want to build.
Pay attention to the minimum size as well. Small parts get lost. You may want to attach tiny parts to a sprue, as used in plastic model kits, to keep them together. Most services will list the minimum size parts that they can work with.