3D Printing Overview
Overview
3D Printing has revolutionized how we approach prototyping and product development. This additive process is perfect for hard to manufacture geometry and quick, iterative prototyping. You start with nothing and add material to create your object.
As the industry has progressed, many types of printing technologies have emerged, such as stereolithography, multijet fusion, polyjet, and fused deposition modeling. Each of these processes have their own materials, benefits, and restrictions. Below we've listed the tradeoffs of each technology in terms of materials, resolution, speed, quality, and cost.
FDM (Fused Deposition Modeling)
Materials
Thermoplastics (ABS, PLA, Nylon)
Material Cost
Low
Resolution
Low
Speed
Slow
Pros
Good for building large, low cost parts.
Cons
Parts are slow to build and can delaminate.
Surface finish is often inconsistent and "ridge" like.
ColorJet
Materials
Composite Powder
Material Cost
High
Resolution
Medium
Speed
Fast
Pros
Build large parts with even surface finish.
Print in color.
Easy to finish material.
Cons
Material can be brittle.
Involved post processing.
SLS (Selective Laser Sintering) / MJF (Multi Jet Fusion)
Materials
Nylon
Material Cost
Low
Resolution
Medium-High
Speed
Fast
Pros
Can build cheap but durable parts.
Cons
Nylon can absorb moisture.
Large, flat parts tend to warp due to heat in post processing.
Harder to custom finish due to abrasion resistance.
SLA (Stereolithography)
Materials
Assorted types of Photopolymers
Material Cost
High
Resolution
High
Speed
Slow-Medium
Pros
High resolution prints with plenty of material property options.
Clear/translucent materials.
Cons
More expensive.
Support structures can leave surface defects.
MultiJet / PolyJet
Materials
Assorted types of Photopolymers
Material Cost
High
Resolution
High
Speed
Slow-Medium
Pros
Materials and colors can be mixed digitally for custom results.
Multi-material 3D prints, useful for overmolds.
Clear/translucent materials.
Uniform surface finish.
Cons
More expensive.
Some post processes use heat which can warp parts.
DMLS (Direct Metal Laser Sintering)
Materials
Assorted types of Metals
Material Cost
Very High
Resolution
Medium
Speed
Slow
Pros
Great for hard to machine metal parts.
Cons
Very expensive.
3D Printing Limitations
Compared to other fabrication processes, there are very few material options out there for 3D printing, and no way to produce production like rubber. A single part takes hours or even days to create, compared to seconds for injection molding and minutes for resin casting. Many printers are restricted by build size, which causes parts to have to be pieced together. And 3D printing machines require significantly more maintenance than other production machines, causing increased labor costs and machine down time. This can be a major challenge for anyone considering buying their own printer.
3D Printing is key to rapid prototyping and moving through the product development process quickly, but it is important to remember that it is just one tool in the tool belt. Other processes like RTV casting and CNC machining exist for a reason, and should be used along side 3D printing.
