3D printing, also known as additive manufacturing, refers to processes used to synthesize three-dimensional objects by building layer upon layer of materials under computer control. In contrast with subtractive methods like CNC machining that remove material from a solid block, 3D printing starts with loose material in powder, liquid or filament form and then precisely solidifies it to produce the final shape based on a digital 3D model.
The technology has revolutionized product design and manufacturing across industries, enabling rapid prototyping, creation of complex and customized parts, reduced waste and production of objects not possible through traditional methods. There are now several types of 3D printing methods available to suit different applications and budgets.
Overview of 3D Printing Methods
Broadly, 3D printing technologies can be divided into three categories:
- Polymer 3D Printing: Uses plastic materials to build 3D objects. Most suited for prototypes, concept models.
- Metal 3D Printing: Uses metal powders or wires to print end-use functional components. Ideal for tooling and end-use parts.
- Ceramic 3D Printing: Uses ceramic powders to produce ceramic objects. Used in aerospace and medical implants.
Within each category, there are several sub-types of 3D printing that use different technologies. Let‘s examine the most common methods ranging from desktop to industrial solutions:
Polymer 3D Printing
Polymer 3D printers allow printing plastic components using materials like ABS, PLA, Photopolymers etc. They are the most widely used 3D printing methods suitable for concept models, prototypes and custom accessories. Based on the technology used, popular sub-types include:
Stereolithography (SLA)
SLA printers use an ultraviolet laser to selectively cure and solidify liquid plastic resin layer by layer until the object is complete. Objects display excellent detail with smooth surfaces and tight tolerances. However, raw prints are brittle and require additional post-processing.
- Typical Layer Height: 25-100 microns
- Cost: $$-$$$
- Key Materials: Resins (Epoxy, Acrylate)
- Ideal Applications: Detailed prototypes, patterns, medical models
Affordable Desktop SLA Printer
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Selective Laser Sintering (SLS)
In SLS printers, a laser selectively fuses powdered plastic material layer by layer based on a cross-section from the 3D model to build an object. It produces durable components with intricate details unattainable through traditional methods. Does not require support structures.
- Typical Layer Height: 75-200 microns
- Cost: $$$$
- Key Materials: Nylon Plastic, TPU, PEEK
- Ideal Applications: Functional prototypes, end-use parts
Fused Deposition Modeling (FDM)
FDM printers melt and extrude thermoplastic filaments through a nozzle onto a platform layer by layer until the object is formed. Affordable desktop models make this the most common 3D printing process for novices. Parts display visible layers with weaker strength in certain orientations.
- Typical Layer Height: 50-400 microns
- Cost: $-$$$$
- Key Materials: PLA, ABS, PETG
- Ideal Applications: Concept models, prototypes, hobby projects
Affordable FDM Printer
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Digital Light Processing (DLP)
Similar to Stereolithography, DLP 3D printers also utilize photosensitive polymers and light to create layers. But instead of lasers, DLP uses a digital projector screen to flash images onto the resin surface curing an entire layer at a time. Ideal for high detail prototyping applications.
- Typical Layer Height: 25-100 microns
- Cost: $$-$$$
- Key Materials: Resins (Epoxy, Acrylate)
- Ideal Applications: Jewelry, dental products, detailed miniatures
Multi Jet Fusion (MJF)
MJF printing greatly resembles the Selective Laser Sintering process. But instead of a laser, MJF utilizes inkjet printheads to selectively deposit fusing and detailing agents onto a nylon powder bed before applying heat to solidify layers. It delivers excellent mechanical properties.
- Typical Layer Height: 80 microns
- Cost: $$$$
- Key Materials: Nylon
- Ideal Applications: Functional prototypes, end-use parts
PolyJet
The PolyJet process involves jetting layers of curable liquid photopolymer onto a build tray and curing them with UV light. It facilitates multi-material printing mixing rigid and elastic polymers to achieve desired mechanical properties.
- Typical Layer Height: 16 microns
- Cost: $$$-$$$$
- Key Materials: Photopolymers, Elastomers
- Ideal Applications: Concept models, product mockups
Metal 3D Printing
Metal 3D printing builds fully-dense metal components that can withstand extreme environments. The high costs restrict them to critical applications in aerospace, defense, automotive and medical sectors. Here are some popular metal 3D printing methods:
Direct Metal Laser Sintering (DMLS)
DMLS utilizes a laser to fuse metallic powder microparticles by scanning cross-sections from 3D CAD data. The high precision delivers complex geometries impossible through machining. Parts possess material properties similar to traditional processes.
- Typical Layer Height: 20-100 microns
- Cost: $$$$
- Key Materials: Aluminum, Steel, Titanium, Superalloys
- Ideal Applications: End-use components, injection molds
Electron Beam Melting (EBM)
Instead of lasers, EBM employs a powerful electron beam in a vacuum environment to melt metal powder layers based on a digital model to build a 3D object. Develops near net shape components with material qualities better than cast and comparable to wrought materials.
- Typical Layer Height: 50-200 microns
- Cost: $$$$
- Key Materials: Titanium alloys, Nickel alloys, Cobalt Chrome
- Ideal Applications: Orthopedic implants, aerospace components
Binder Jetting
Binder jetting deposits liquid bonding agent selectively onto a bed of metal powder. The final bound component is then sintered in a furnace to fuse the particles and achieve over 99% density while retaining detailed features.
- Typical Layer Height: 25-150 microns
- Cost: $$-$$$
- Key Materials: Stainless Steel, Aluminum Alloys
- Ideal Applications: Metal casting patterns, tooling components
Factors Influencing Choice of 3D Printing
With numerous 3D printing methods to choose from, several technical and economic considerations can guide selection:
1. Mechanical Properties
Based on layer adhesion strengths and porosity levels, different 3D printing can achieve around 20-100% of solid metal tensile strength values. DMLS and EBM lead in terms of best strength-to-weight ratios.
2. Accuracy and Surface Finish
Precision standards range drastically across techniques. SLA and DLP produce high-definition smooth surfaces while FDM makes visible layer lines on sloping walls. Average part tolerances differ between 50 microns to 0.5 mm for most polymer printing while DMLS and EBM can match CNC machining grade accuracies.
3. Build Size
Entry-level desktop 3D printers typically allow build volumes up to 8”x8”x8” only whereas industrial class production systems offer cubic meter range capacity enabling larger parts fabrication.
4. Production Scalability
3D printing best serves low volume batches less than tens of thousands of units due to limited speed. Traditional mass manufacturing methods surpass for very high runs through enhanced automation.
5. Lead Time
A key benefit 3D printing is enabling rapid concept iterations and functional prototypes within days rather than weeks or months for conventional tooling-based approaches.
6. Part Cost
With volume production, conventional manufacturing achieves lower cost per part up to 70-90% reduction versus additive manufacturing. 3D printed parts become economical only for very complex, customized or small-scale applications.
Getting Started with an Entry-Level 3D Printer
For novices getting started with understanding and experiencing 3D printing hands-on without breaking the bank, an inexpensive FDM printer offers the best solution.
The Official Creality Ender 3 V2 demonstrates immense popularity within the hobbyist segment providing great value featuring:
- Generous build volume of 8.6” x 8.6” x 9.8”
- Reliable extruder system and heated bed
- Intuitive color interface and remote monitoring
- Large online knowledge base and accessories market
With the Ender 3 V2, you can gain practical experience working with 3D models, slicing software and printing a diverse range of objects using PLA, PETG, TPU and other materials. Additional upgrades like auto bed-leveling probe and all-metal hotend enhance consistency further.
Overall, it delivers astonishing print quality right out the box at nearly one-fifth the cost of equivalent industry-grade FDM printers costing over $2000+. For advanced users, the 300 x 300 x 400 mm build volume Creality CR-10 MAX model proves an even better option for macro projects.
Conclusion
The area of 3D printing has expanded enormously over the past decade in terms of capability, reliability and choice of solutions fitting applications across the prototyping-to-production spectrum. Whether you require concept models, functional prototypes, jigs and fixtures, end-use components or even human implants, appropriate printing systems exist to deliver.
With this guide spanning entry-level to advanced methods, you should now possess broader insight regarding suitable 3D printing selection for your needs taking into account key parameters like target material, accuracy, cost constraints and more. Leveraging these additive technologies judiciously promises to unlock greater innovation and productivity gains further.
