1. How it Works EP 413 Syd Ullrich October 19, 2017
3D Printing
How it Works
EP 413
Syd Ullrich
October 19, 2017

2. Table of Contents Mechanisms Extrusion Stereolithography Components
Type Differences
Motors
Bed and Chamber
Print Head
Software
3D Modeling
Translation to printer

3. Extrusion (Fused Deposition Modelling)
Forces filament through a heated print head Molten filament bonds with previous layers Cools into a solid If you can melt your material in a kitchen stove, you can print with it for example chocolate Temperature limited, needs filament, overhangs require added support

4. Extrusion Materials
Extrusion printers use variety of plastics: PLA: Sugar-based, most common filament, very easy to print, recycles indefinitely ABS: Cheap, strong-ish, hard to print, Lego is made of ABS Nylon: Extreme strength, low friction, more expensive, needs to be cooked Ninjaflex: In case you want to print rubber

5. Stereolithography & Sintering
Lays down a whole sheet of material Lasers some of the material into being solid Can work with anything from liquid resin to powdered steel Lasers that can melt steel are expensive and a bit dangerous, needs a powder or liquid

6. Stereolithography Materials
Desktop stereolithography printers often use a UV sensitive resin Material doesn’t vary much between printers End product similar to PLA
Industrial printers will be the ones using powdered metal
Can use pretty much anything they can melt

7. Bed and Chamber
Printers using ABS or nylon often equipped with a heated print bed Print beds are usually mobile on the vertical axis Stepper motors or servos to get the needed precision Some printers have the whole print chamber heated

8. Print Head
Extrusion printers have motors to pull the filament Heated nozzle to melt it Mobile along the x and y axis via stepper motors STL printers have a laser and mirror system Precision tilting steers the laser

9. Modeling Software
Sketchup: Extremely basic Solidworks: Can run FEA, expensive Blender: Has a lot of options Shapeways: Uses minecraft

10. Conversion
Converting a solid model happens in multiple steps First the model is converted into triangles to ensure quality. Triangle mesh then gets converted into g-code. G-code tells the printer how to move.

11. Summary
Most 3D printers use either fused deposition modeling or a stereolithographic process. Can print with just about anything if you have the right printer. Use a few extremely precise motors to control the printing. Huge variety in both software and hardware.

12. References
Image Sources included in image alt text