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Prototyping: Why 3D Printing is the Obvious Choice

By Mitch

November 20th, 2023


A cross-section of a 3D printed turbine
Prototyping comes together, piece by piece

Prototyping has taken great leaps forward in recent years and Politech is always at the forefront of those advancements. In this article, we’ll be taking a look at what prototyping is and how 3D printing is the economical choice for all your prototyping needs.


First though, let’s answer one question.


What is prototyping?


Prototyping is the best way to produce an early sample of either a proposed new item or one that is already in production. The prototype itself can either be an exact copy of the real object or a scaled down model of a larger piece of machinery for example.


Previously, producing a prototype was left to the engineers themselves to make a preview model of the item to present to the manufacture for approval. This could be a time consuming process which would sometimes involve actually making a working version of the item which, to all intents and purposes, was the finished production object.


Take for instance a jet turbine (yes, we’ve gone big straight off the bat!). This is an extremely large and complex machine to make and could take many man hours to machine tool and assemble the multiple moving parts. It’s also essential that a machine such as this works perfectly as it’s likely to be used on an aeroplane and failure there isn’t an option. Therefore rigorous testing of each turbine that comes of the production line is a given.


To produce a prototype of a jet turbine using traditional methods though may, as we’ve mentioned, involve exactly the same process as building the actual object so is a very time consuming and expensive process.


This is where 3D printing comes in!


3D Printing and Prototyping


So, you’ve got the blueprints and design sorted for your production item but you need to be sure that all the parts are working, move in the way that they should and ultimately serve their purpose.


As we’ve said, prototyping is the next stage in the design process but with our example of the jet turbine, we may want to cut costs and reduce production time of the prototype. In the manufacturing business time is money so getting to the production line quickly is key. This is where 3D printing can save on both aspects of time and money.


Let’s then look at why that is.


Materials


The obvious one really but one that can’t be understated. Again, with the example of the jet turbine, there are many parts that need to be made individually and to a precise nature. 3D printing allows for this exact precision without the need for individual parts to be made from the same material as the actual engine. The use of either liquid resin or plastic filament is a far more cost effective way of producing these parts and constructing the prototype. We’ll be looking briefly at the different 3D printing methods later on.


Machinery


The machinery used for 3D printing is generally pretty compact and in a lot of cases could almost be considered “desktop” size. These machines can cost anything from around $200 to upwards of $10,000 but at that point you’re getting into the serious realms of the process. The method of printing or cost of the machinery though isn’t really the concern of the prototyping customer but may have a knock on effect from the provider. It’s safe to say though that you can get just as good results from a 3D printer at the lower end of the price scale as you can from a high end machine.


Speed


Getting a prototype produced quickly and efficiently could mean the difference between getting a product to market or even landing the contract to manufacture that product. 3D printing has the capability to produce items quickly and to a high degree of precision and detail. 3D printing technology is constantly changing and advancements in printing speeds are at the head of the line in that regard. Of course, making something quicker doesn’t necessarily make it better but in the case of 3D printing developments have allowed speed without a drop in quality.


With that in mind, maybe its now time to look at the different types of commonly used 3D printing methods used in everyday printing as well as prototyping.


3D Printing Methods


In our previous article, "3D Printing: Comparing FDM, SLA and SLS", we looked at the three most commonly used methods of 3D printing for prototyping as well as general use. Let's then just remind ourselves of what these methods are and how they work.


FDM


A 3D prinyed yellow boat
FDM printing is the most common and easy to use


Fused Deposition Modelling or FDM for short is the most commonly used and form of 3D printing and particularly popular among home users or hobbyists. The process involves heating a solid plastic filament and extruding it in thin layers which are deposited onto a build plate area. The layers then build up gradually to form the full shape of the 3D model.


This process allows for the use of a wide variety of different materials but the most commonly used are PLA (Polylactic Acid) and ABS (Acrylonitrile Butadiene Styrene) with each having its own distinctive properties and uses. PLA in particular is very popular as its easy to work with, is abundantly available from natural materials and fully recyclable. There are of course many other filament types and even some base filaments such as PLA with certain additives such as carbon or wood fibres.


SLA


A resin 3D printer making a human figure
SLA or resin printing gives finer and smaller detail

Stereolithography is more commonly known as SLA but is mostly referred to as resin 3D printing.


SLA also builds the model in layers but uses a liquid resin to do so. This resin is subjected to UV light and the photochemical process that occurs causes chemical monomers and oligomers to react and form into polymers. It’s these polymers that form the solid 3D printed model.


This method of 3D printing is generally considered to be better for smaller, more precise detail but is limited by size as machines tend to have a limited build volume. In terms of prototyping though, SLA can be ideal for producing highly detailed or complex parts that may not work so well with FDM.


SLS


A 3D printed object in an SLS machine
SLS printing allows for greater detail and larger scale

Selective Laser Sintering or SLS is a much different process to both FDM and SLA but is comparative in the use of a layering system to produce the 3D printed object.


The process involves the use of a high-intensity laser as the heat and power source to sinter a powdered material which is usually a nylon or polyamide. By sintering we mean that the powder is subjected to the heat of the laser which then forms it into a solid without heating it to the point where it will liquify.

The build area is known as the powder bed and the laser scans each layer of the digital design before it fuses the appropriate powder into each layer of the object. The powder is gradually delivered from a separate container and then rolled onto the powder bed surface so that the laser can perform its actions.


Aside from the plastic materials mention, SLS can also be used with metal or glass powder so you can then see the potential of what can be produced.


SLS printing however does involve the use of very high-tech machinery, which is shall we say, not cheap! It’s therefore reserved mainly for large industrial use.


Conclusion


So we’ve looked at what prototyping is, the different methods and materials used in 3D printing and how advancements in technology have made 3D printing a faster and cheaper option.


Machinery and materials are readily available and in a lot of cases are made from raw materials that are kind to the environment. The choice of material types is varied and can therefore be used to either create a model prototype or even a direct replica if using materials with certain additives.


This therefore makes the point that 3D printing is an excellent choice for prototyping and also the most economical choice.


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