What is 3D printing? What are the benefits, downfalls and limitations?
A definitive overview of all the rapid prototyping processes available.
Learn more about 3D printing materials & limitations
Learn how to incorporate 3D printing into your design process.
Tips on starting, from ordering online to buying a printer.
3D Printing is an expanding method of industrial production that enables the creation of lighter, stronger parts & systems that drastically cuts product lead times.
Every 3D printer works on the same principle: using data from 3D computer aided design (CAD) or 3D scanners they transform them into a physical model by depositing material layer by layer. This type of process is widely known as ‘Additive Manufacturing’.
Compared to other methods of plastics processing; CNC machining, Injection Moulding, Vacuum Forming, Blow Moulding, Extrusion & Rotational Moulding. This additive method of manufacture requires the least amount to setup and has the lowest overheads.
Additive manufacturing processes such as 3D printing, required no special tools are required (for example; a cutting tool for machining or a mould). Instead the part is manufactured by depositing material layer by layer onto a build platform to create precise geometric shapes. With all processes, this has its benefits and limitation – more information here.
With all manufacturing processes, it’s important to understand its benefits and limitations. It comes with a unique set of advantages, however can be disadvantageous in certain scenarios. Here in this guide we summarise we take into account the pros and cons of all the different 3D printing processes currently available:
3D printing enables users to produce parts with complex geometry which is in some instances impossible for subtractive & formative methods to create.
Compared to other plastic processes, there are little to no initial setup costs to get parts made. You just need the printer and material to get started.
Parts can be made in custom materials, colours or finishes with engravings or logos to make a part personal to that individual or company.
Quick Lead Times
With formative processes such as; injection moulding, blow moulding or rotomoulding new parts can take up to 12-weeks to go into manufacture. However 3D printing can considerably reduce this initial lead time.
Large Range of Materials
There are a number of different materials available for 3D printing, including conductive, metal and ceramics.
Low Strength & Isotropic Properties
Due to the process of 3D printing where layers are deposited on each other, if not properly fused these layers can separate. It’s important to consider print orientation when printing parts to ensure and loads applied are perpendicular to the layer direction.
Part Cost at High Volumes
Due to the nature of 3D printing, it’s a time expensive process which becomes expensive when printing multiple parts. Where cycle times are hours, sometimes days compared to seconds for injection moulding.
Limited Accuracy & Tolerances
Compared to other processes such as subtractive CNC machining, 3D printing has much lower tolerances.
Post Processing & Support Removal
Due to the process of 3D printing, this leaves layer lines in parts. Compared to other plastic manufacturing methods, this can give an undesirable finish which requires some form of sanding, polishing or painting to give a smooth and even finish.
Bottom, free-hanging surfaces usually have inconsistent surface finishes as well. As these areas usually come into contact with supports which are removed once the parts are finished printing.
We put together a few examples to show the different applications of 3D printing and how it can be applied practically.
Aerospace & space engineering firms use 3D printing to produce accurate, high-performance, lightweight components that have complex geometries. 3D printing allows complex assemblies to be simplified into a singular part.
The automotive industry has benefitted hugely from 3D printing. Whether it be used to support research and development during the design stages or used in a support role during manufacture & assembly (jigs & fixtures).
Low cost & constructed in less than 24 hours, 3D printed houses are now a reality. Eindhoven University of Technology are proposing plans to implement this, with the first house ready for occupation in 2019.
Often in classrooms, its difficult for educators to engage with students. Through 3D printing, course subjects can be brought to life through physical models. This provides students with an unforgettable learning experience.
Advances in modern medicine can help prolong life expectancy and prevent disease. 3D printing is a key tool in accomplishing this, helping to create synthetic organs, devices or even used in planning complex surgical procedures.
Numerous companies are now implementing 3D printing into their manufacturing processes. Audi for examples currently provides all factory employees with bespoke orthopaedic devices for pushing snap-fit components
ISO / ATSM 52900 standard classifies all the different 3D printing processes into seven main categories:
Material Extrusion otherwise known as Fused Deposition Modelling (FDM) is the most common type of 3D printing available. Originally trademarked by Stratasys, the process involves material being drawn through a nozzle where it is headed and deposited layer by layer to create a 3D shape.
Using either a laser or electron beam, Powder Bed Fusion (PBM) or Selective Laser Sintering (SLS) harnesses this energy to melt and fuse material powder together. This process involves the spreading of fresh powder material over the previously fused layers, there are a number of different mechanisms that enable this including a roller or a blade.
Similar to an inkjet printer, material is jetted onto a build platform using either a continuous or Drop on Demand (DOD) process. Nozzles move horizontally across the platform similar to material extrusion (FDM), then the layers are cured using Ultraviolet (UV) light.
This process involves two materials; a powder based material and a binder. The binder usually in liquid form, acts as an adhesive where it is deposited from the print head to fuse with previously printed layers. This process isn’t suitable for structural & functional parts and requires post-processing.
Using a 4 or 5-axis arm this process uses a nozzle that mixes material whilst being delivered using a laser or electron beam. DED is typically used for 3D printing metals, however can also be used to print ceramics and polymers.
Broken down into two different processes Ultrasonic Additive Manufacturing (UAM) and Laminated Object Manufacturing (LOM). These processes involve the layering of sheet or ribbon material and then being cured or bonded. Both processes require additional CNC machining and post-processing.
Acrylonitrile Butadiene Styrene (ABS)
One of the first 3D printing materials available on the market. This material is well-regarded for its toughness and impact resistance.
Polylactic Acid (PLA)
The most commonly available 3D printing material on the market. Derived from crops it’s environmentally friendly as it is renewable and biodegradable.
Popular engineering grade 3D printing material known for its impact resistance, strength and flexibility. Also chemically resistant to diesel and petrol.
Intended for tough environments & engineering applications Polycarbonate is known for strength, durability and its high heat deflection.
Acrylic Styrene Acrylonitrile (ASA)
Well known for its impact resistance and strength like its similar counterpart ABS. It’s highly UV stable due to an rubber additive in its formulation.
Polyether Ether Ketone (PEEK)
Incredibly temperature and chemically resistant, PEEK is a specialist engineering material which is capable of operating in tough environments.
Thermoplastics Polyurethane (TPU)
One of the few flexible 3D printing materials available on the market today. Useful for parts that require an elastic / rubber feel (tyres for example).
Polyethermide (PEI / ULTEM)
Well known for its exceptional heat, chemical and flame resistance properties. Similar to PEEK it performs well in high performance applications.
For all 3D printing processes, a 3D file is required. The most common format for this in additive manufacturing is ‘STL’. When designing parts, it’s important to consider the limitations of the manufacturing process and to follow the design guidelines
There are a number of software solutions that can export STL files. We’ve listed all the different packages available that are used by ourselves, our customers and our support network.
Here are some packages we recommend:
If you are new to design (or if you are simply looking for something to print fast), then one of the many online repositories might already have what you are looking for.
Here are some websites we recommend: