Why did I create this? I recently decided I wanted to really test 3D printing's potential as a manufacturing technique, this did not mean see how well it can just print a boring plastic part that could have just be injection molded for a fraction of the price like many 3D pieces printed we see now through services such as Shapeways, this meant designing something that could only be produced using 3D printing (and it had to be awesome!) while showing 3D printing to be a potentially very useful technology in the future due to one of it's two main advantages; the first has already been well documented about; this is about how 3D printing can be used to produce complex 3D geometries that would be impossible to produce using any other manufacturing technique, however these complex 3D geometries are generally just created for their aesthetic appearance and while they are generally very impressive, they have no real potential use or meaning that could portray 3D printing as a more practical manufacturing technique than current techniques for mass production.
In this instructable, I attempt to explore this second advantage of 3D printing and this is it's ability to print moving parts by printing whole assemblies in one print with all moving parts printed fully assembled, unlike the other advantage, this advantage really has a potential to change the way we mass produce devices which have moving parts; by 3D printing all moving parts in place, this completely removes the need for assembly, either by the manufacturer, which costs them money to employ people, as well as the time for the assembly to take place, or by the buyer which is again time consuming and can be complicated.
What is it? To fully test out 3D printing's ability to produce complex mechanical parts fully assembled I designed the '28-Geared Cube' which is a 3D printed desk toy which, as it's name suggests, is a cube with 28 gears on it; by rotating any one of these 28 gears, the other 27 gears also turn in a mesmerizing pattern. This was 3D printed using the 3D printing service Shapeways in the White, Strong and Flexible material. While I did want to test 3D printing, I also wanted to design something that I felt looked good and really made you question what was going on when you turn the gears.
To achieve this, the 28 gears are arranged so on each of 4 sides of the cube are 7 gears: 2 large outer ones that move in opposite directions, the outermost gear has handles on it so it can be easily rotated, the motion between the 2 large cogs on each face is reversed due to 5 smaller gears set within the cube in a similar layout to a planetary gearbox to reverse the big gears' direction on each of these 4 faces. Each of these sets of 7 gears on the 4 faces are all liked through one of the big gears on each of the 4 faces meshing at 90 degrees with one of the big gears on each of the 2 neighboring sides. This means that if any one gear is spun, they all spin in a memorizing pattern.