Choosing the right 3D printer

A 3D printer uses an additive manufacturing process, i.e. it manufactures an object layer by layer: either by adding material, solidifying a liquid or powder binding. Unlike conventional machine tools that make it possible to create a part by removing material through machining, this technology creates objects by adding layers of material. It reduces production times compared to conventional machining processes and provides very high precision in the production of complex shapes.

Unlike molding techniques, which require the mold to be made before material can be poured into it to manufacture the part, 3D printers work directly from a digital file that is cut into “slices” corresponding to each layer of material.

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What materials are used in 3D printing?

Makerbot PET filament for 3D printers
Makerbot PET filament for 3D printers

Different materials are used for different types of 3D printers. Below is a list of the most commonly used materials (the technologies listed below are described in the next section):

 

Form of the original material Type of material Technology Market Distinctive features Appearance of the finished part
Filament PLA (plant-based polymer) FDM

FFF

General public

Professional

Food industry compatible Rough
ABS (thermoplastic) Better mechanical properties than PLA
PET (polyethylene terephthalate) Good mechanical resistance
Powder Polyamide SLS Prototyping Very good level of detail

Food industry compatible

Ceramic, Glass SLS

Binder Jetting

Research laboratories

Design

Food industry compatible
Alumide (combination of aluminum and polyamide) DMLS

EBM

Prototyping Good mechanical properties
Titanium, stainless steel, aluminum, cobalt, iron, bronze, etc. Prototyping

Small volume

Aeronautic

Automotive

Good mechanical properties
Silver, platinum, gold, etc. Jewelry
Liquid Wax SLA

DLP

PolyJet

MJM

Jewelry

Dentistry

Modeling

Very good level of detail

Fragile

Smooth
Polymer resin Prototyping

Small volume

Medical

Smooth

Directly dyed in the mass

 

Much research is underway to replace current materials such as ABS, from the oil industry, and PLA, from intensive agriculture, with more environmentally friendly materials such as clay, mud, wood pulp, locally produced grain or algae (SWF).  In the field of construction or civil engineering, 3D printers that can use specific mortars are also emerging.

What are the main 3D printing techniques?

 

Technology Principle Comments
Fused Deposition Modelling (FDM) The 3D printer heats the filament (PLA, ABS, PET, etc.) to make it soft and malleable and places it in successive layers on a tray.

When the part has fragile areas (for example a tray on a narrow base), it is necessary to provide support areas that will be removed after the part has been manufactured.

Printers intended for the general public. You can use this technology for prototyping and to manufacture single parts, for after-sales service for example.

The parts manufactured may be of a good level of accuracy depending on the printer, but for complex parts we advise that you use SLS technology instead.

Fused Filament Fabrication (FFF)
Selective laser sintering (SLS) The 3D printer uses a laser beam that solidifies a powder (polyamide, ceramic or glass) layer by layer to produce parts that can have a high level of detail.

When manufacturing complex parts or parts with fragile areas, there is no need for supports as the fragile areas are supported by the unfused powder.

Parts generally have a sandy appearance when they come out of the printer and must go through a polishing phase to obtain a good finish.

Parts printed in SLS have good mechanical properties.

Direct metal laser sintering (DMLS) The 3D printer uses a laser beam that solidifies a powder (polyamide, ceramic or glass) layer by layer to produce parts that can have a high level of detail. These printers are increasingly used in cutting-edge industries such as aeronautics and the automotive and medical fields.

They represent a significant initial investment, as well as high maintenance costs, but they make it possible to produce very complex parts with mechanical properties comparable to those of parts obtained in traditional ways such as machining or casting.

Electron beam melting (EBM) The 3D printer uses an electron beam that solidifies a powder (steel, cobalt chromium, aluminum, titanium, etc.) layer by layer to produce very complex parts that could not be manufactured otherwise. The manufacturing process is carried out under vacuum, which prevents the unsolidified powder from oxidizing. This can as a result be reused immediately.

This technology can only be used for conductive materials. It is faster but a bit less precise than laser technology (DMLS).

Stereolithography (SLA) These 3D printers use an ultraviolet ray to solidify the resin. The parts obtained are very precise and have a very good surface finish.

This technique is particularly appreciated for its speed both for prototyping and mold making.

Digital Light Processing (DLP) This technology uses a projector that does not need to move horizontally and makes printing faster than SLA.
PolyJet These printers combine the emission of ultraviolet light with the projection of micro-droplets of photopolymer material (which hardens under the effect of ultraviolet light). This technique makes it possible to combine different materials that may have different mechanical properties depending on requirements (rigid or flexible materials for example).

It is used in both toy manufacturing and the aerospace industry.

MultiJet Modeling (MJM) These printers spray the liquid material that then solidifies as it cools. They are equipped with several print heads, one of which is used to create the material (for example wax) at the same time as the part. The parts produced are very precise and can be made of multiple materials depending on the number of print heads.

This technology is especially used in jewelry making and mold manufacturing.

3D printers used for building or civil engineering also work with spraying.

Binder Jetting

Powder Binding

These printers spray a binder, which can be colored, onto a powder applied layer by layer. With this technique it is possible to produce very complex colored parts. However, it is necessary to remove the excess powder by blowing or vacuuming.

What are the main uses for 3D printers?

HP 3D printer
HP 3D printer

The first 3D printers were used in industry for prototyping, but the medical and dental industries quickly became interested in this technology both for bioprinting (the manufacturing of cellular structures) and for the manufacturing of prostheses.

Industries linked to transportation like the aeronautic, aerospace, shipping and automotive sectors are also increasingly using 3D printing which makes it possible to obtain lighter parts with equivalent or even improved characteristics compared to traditionally manufactured parts.

This technology is also widely used in architecture and civil engineering for the production of models as well as in the direct manufacturing of buildings or structures such as bridges.

What are the advantages to 3D printing techniology?

The main advantage of 3D printing is that it can work directly from a CAD file (a 3D file produced by a design office, for example) using a minimum amount of material, unlike traditional machine tools, which generate a lot of chips or shavings that must then be recycled. This kind of manufacturing also doesn’t require lubrication, which greatly limits the risk of pollution.

Another advantage of 3D printing is the ability to create parts with very complex shapes that would be difficult to achieve with traditional processes (machining, forging or casting). Additionally, 3D printers allow the creation of increasingly large parts. First intended for prototyping, 3D printing now allows mass customization by being able to manufacture parts with slight differences, as well as small scale production at competitive prices. With high speed 3D printing, production time is increasingly reduced. This makes it possible to consider producing medium or large series in the shorter term.

The visual aspect of the parts is one of the few problems related to some aspects of 3D printing. If the parts are to be visible on the finished product, they must undergo polishing first. But if they are hidden (gear wheels for example), they will not need a perfect finish and can be used as they are.

Advantages of 3D printing:

  • Reduced production costs
  • Reduced manufacturing time
  • Fewer errors
  • On-demand production

 

What are the market trends?

3D printer by Shining 3D
3D printer by Shining 3D

3D printing is an evolving market. The first 3D printers were limited to the use of a single material and designed to produce very small objects. The parts created did not have strong mechanical properties. Today, we are seeing the emergence of multi-material printers and ones that can produce very large objects. Whether in the medical field, in the industrial field or in architecture, we can expect these machines to soon create complete organs for transplants or complete multi-material products that are directly functional. One of the promising markets for 3D printing is the repair market. Major household appliance manufacturers offer spare parts made using this technique.

Hybrid machines are also emerging that combine 3D print heads on numerical control machines that use, for example, the WAAM (Wire Arc Additive Manufacturing) process, which is a deposit welding process used to produce titanium parts in particular.

The consumer market is growing rapidly and represents a significant share for manufacturers. It is possible that in the long term it will be in competition with Fab Labs, which offer advice and services to go with 3D printing services.

On an industrial level, printers are emerging that make it possible to work with highly technical materials and that are capable of producing large parts. From now on, manufacturers are offering 3D printing services in addition to selling the machines. Their printing centers make it possible to use different printing techniques without having to bear the cost of investing in the machines themselves.

How much does a 3D printer cost?

To compare the prices of 3D printers, it is necessary to distinguish between machines intended for the general public and industrial machines. Industrial and consumer 3D printers are distinguished by their printing volume, accuracy, printing speed, sound level and the materials they can use.

On the consumer market, FDM printers that print in PLA monofilament with a maximum volume of 200 x 200 x 200 x 200 mm and an accuracy of 100 microns can be found starting at €300.

On the professional market, FDM printers that print in PLA or ABS bi-filaments with a maximum volume of 200 x 200 x 300 mm and an accuracy of 50 microns can be found starting at €4,000.
For stereolithography printers, you can expect to pay between €10,000 and €150,000.
For printers that allow you to create metal parts, you can expect to pay over €100,000.