FDM 4 2 2 2 Thermoplastic

More details & datasheets. This is currently the most widespread form of 3D printing. All new machines are built by Stratasys under the names Dimension or Fortus. Each layer is made by extruding a thin filament of nearly-melted thermoplastic onto a build surface. It builds in a criss-cross fashion, so that each layer's “grain” is perpendicular – which makes the part stronger. It's support material comes in break-away and soluble forms – the latter allows for much more complicated geometries by allowing water to wash away support. Strengths Plastics used are very durable

Wide variety of materials are available

Soluble support technology (SST) allows for intricate geometry, including simple moving parts Weaknesses Untreated surfaces have a rough finish

Strength along the Z-axis direction is far less than in X or Y (because of layer adhesion)

Slower build-times with multiple parts Minimize

SLA 3 5 4 4 Resin

More details & datasheets. This was the original form of 3D printing. Currently, all systems are built by 3D Systems. The process forms each layer by scanning a UV laser over a build surface covered in a special resin that cures when exposed to UV light. The plate lowers into a vat to re-coat the surface for each layer. Support material is the resin itself. Strengths Accuracy

Good surface quality

Wide variety of materials Weaknesses Long post-processing times (due to removing support material)

Resins are toxic & unsafe for an office environment Minimize

SLS 4 4 3 3 Nylon

More details & datasheets. The SLS process is often used for durable production parts. The material used is usually a form of nylon (polyamide) powder - often containing another material to enhance the properties. A laser passes over the powder - sintering it together to form each layer. The unsintered powder acts as the support material and once the part is complete it can simply be shaken off (or using air for internal geometry). Strengths Durable, production strength parts

Wide range of functional materials available

Ability to produce moving parts & intricate geometry

Fast at making multiple parts per build Weaknesses Weaknesses Long flat parts can deform laterally during printing

Moderate surface detail

Rough surface finish Minimize

SLM 5 4 4 3 Metal

More details & datasheets. In this process, a laser is scanned across the top of a compacted powder surface. The laser is strong enough that it sinters / melts the metal powder together. The process produces the highest accuracy for a direct metal process - however there is a steep price tag for this. Like its cousin, SLS, the powder is used as a support material that simply falls away when the part is complete. Strengths Wide range of materials

Very durable parts

Novel material properties (grain structure, lattices, etc.)

Accurate

Good at bulk jobs (because each layer can be sintered quickly) Weaknesses Expensive

Mediocre surface quality

Large flat parts tend to warp Minimize

ZCorp 2 3 3 2 ZCorp

More details & datasheets. ZCorp is a type of 3D printing that creates each layer by using an inkjet head to deposit binder onto a bed of compacted powder. Powder is layered and cured in succession until a part is formed. After each build, the loose powder is removed leaving only the part remaining. The fresh part is then coated in elastomer which gives the parts added rigidity. Some machines have the ability to print parts in full color. Strengths Fast part production

Intricate geometries

The only full color parts process Weaknesses Fragile parts – even when coated

Not good for durable / functional prototypes

Material selection is limited Minimize

PJet 3 4 5 5 Resin

More details & datasheets. PJet can be either PolyJet, produced by Objet Geometries, or ProJet, produced by 3D Systems. This form of 3D printing lives up to the name “printing”. These machines work similarly to inkjet printers, but instead of using ink they use resin. The resin is jetted onto the surface and then cured by a passing UV light – similarly to the SLA curing. The support material isn't quite soluble, but is washed away by a jet of water. Objet's Connex systems can print in multiple materials at the same time. This allows models to have transparent features with opaque internal parts. Also, using their “Digital Materials” technology, you can even intermix the materials with a variable ratio to allow parts with multiple materials properties in one build (see pictures). Strengths Great Accuracy

High Resolution / Feature Detail

High complexity parts

Moving parts are possible

Ability to print in multiple-materials in same build Weaknesses Expensive

Support can be difficult to remove in some circumstances – limiting some geometries Minimize

FTI (V Flash) 3 3 4 4 Resin

More details & datasheets. This system was released by 3D Systems to reach the low-cost / desktop market. Each layer is applied using plastic sheet coated with resin which selectively cured for each layer. Strengths Inexpensive machine cost

Good accuracy

Good resolution Weaknesses Supports made of build material

high post-processing time

Limited part size

Materials are expensive Minimize

Perfactory (EnvisionTec) 3 4 5 5 Resin

More details & datasheets. This technique is exclusive to EnvisionTec and is similar to SLA in that it uses a vat of light-curable resin. Instead of using a laser, it uses a DLP chip and a UV light source to cure each layer in one step (no XY scanning). This makes it five times faster than SLA. Strengths Accurate

High Resolution / Feature Detail

Fast

Casting friendly materials Weaknesses Expensive (machine purchase cost)

Accuracy fall-off (more accurate in the center than edges) Minimize

ProMetal 5 3 3 2 Metal

More details & datasheets. This technique is named after the trade name of the company that builds it: ProMetal. The process is similar to Z Corp where an inkjet head deposits binder onto a powder surface. The difference is that the powder is stainless steel and must be sintered in an oven. Later, the part is “infiltrated” to full density by heating the part in the furnace over bronze. This produces a hybrid SS / bronze material – gold is also possible. Strengths Cheapest metal printing

Bulk part printing

Ability to print very large parts Weaknesses Lower accuracy than SLM

Limited materials

Casting quality surface finish Minimize

MakerBot 4 1 1 1 Thermoplastic

More details & datasheets. MakerBot is the most popular form of DIY 3D printing. It's technically the same as the FDM process, however since it's "maker-ready" we thought we'd give it its own category. There are a few other 3D printers that are similar: RepRap, Fab@Home, and the RapMan. Strengths Very affordable ($750 for a MakerBot kit)

Open source hardware & software

Great community constantly innovating Weaknesses Requires tweaking to work reliably

Early in development: low accuracy / surface finish

No support material for complex geometries Minimize

LOM 2 2 3 3 LOM

More details & datasheets. This process uses layered sheets of material (usually paper or plastic) that are cut out by laser or blade and adhered together. The latest version of this process is the Mcor Matrix which uses A4 printer paper and PVA glue to make prototypes. Strengths Cheapest material available (Mcor)

Thin layer thickness

Greenest 3D printing technology Weaknesses Limited material selection

Support material limits some geometries Minimize

SolidScape 1 5 5 5 Wax

More details & datasheets. The SolidScape process deposits melted wax using an ink jet system. The parts created by this process are exclusively used for wax patterns for the lost wax casting process. In this process, a wax pattern is placed into a mold and burned away in a kiln - leaving a void in the mold. Metal is then poured into the mold, filling the void and creating the desired part. This allows a design to be printed in wax and then cast with extremely fine detail - needed for jewelry, dentistry, and other applications. Strengths Very high feature detail

Great for small / complex parts

Many metals can be cast using the wax patterns

Weaknesses Very delicate wax parts

Small part size

Two step process to get end product Minimize

BioPrinting 1 5 5 1 Bio Materials