The Basics

The 3D printing process is relatively straight forward process when broken down into its basic components. Three main categories of 3D printing are prevalent: a laser solidifying photoreactive liquid, a heat source baking a material, and an extruder guiding molten material. All three methods essentially utilize the same process of having software slice up the model into many two-dimensional shapes. Then, use a CNC (Computer Numerical Control) to begin printing layer by layer until the model is complete. The last process mentioned above is the most common method called Fused Deposition Modeling (FDM) and is also the process chosen for low gravity operations.

Explanation

At first, it may be surprising to beginners when a print takes several hours to finish, but after some simple calculations, the seemingly long duration makes sense. If the printer head prints at 60 mm/s, the nozzle diameter is 0.4 mm, and the Z axis step is 0.2 mm, then the time to print time to make a hollow 100mm cube would be calculated as follows:

First, let us split up the model into the top layer, middle section, and bottom layer.

To find the time for the bottom and top layer, find the time it takes for square millimeter

(60 mm/s) (0.4mm) = 24mm^2/s

Then find the number of paths the extruder would have to take

(100mm / 0.4mm) (100mm / 0.4mm) = 62,500mm^2

Now, convert the area to seconds with the equation above

62,500mm^2 / 24mm^2/s = 2604.17s

For the middle section,

(100mm)(4)=400mm perimeter

Find the time it takes to print one layer

400mm / 60mm/s = 6.67s per layer

The number of layers in the middle can be found

(100mm – 0.4mm) / 0.2mm = 498 layers

Then find the time for the middle

(498 layers) (6.67s/layer) = 3321.66s

Adding up the bottom, middle, and top times gives the result

2604.17s + 3321.66s + 2604.17s = 8530s

8530s / 60s/m / 60m/hr = 2.37 hr