How to choose between rapid prototyping techniques

Posted By Amandine Richardot on Dec 11, 2017 | 0 comments

An optimized product development process is key for any company. To build the best products, you need to go through a successful phase of research and prototyping. And to remain a competitive company, it’s essential to make your product development process faster and faster. A key step in this process is prototyping. We understand that you might be struggling to define which prototyping technology would be the best for you. Rapid prototyping tends to become more and more popular since it allows to develop products in a shorter amount of time, and thus to remain highly competitive. But what is rapid prototyping exactly? Which are the main rapid prototyping techniques? How to choose the right one for your project? Which material would be the best? Here is our special guide for a successful rapid prototyping project!

What is Rapid Prototyping?

Rapid prototyping technologies are techniques used to create a real-scale model of an object in a short lead time, using CAD software. They include 3D printing, subtractive manufacturing (turning, milling, drilling) and casting.

Building a competitive prototyping process: A real challenge

Having an efficient and fast prototyping process is now key for any business. Indeed, it’s one of the major concerns of companies these years. For instance, in our annual study, The State of 3D printing, 28% of our respondents told us their top priority for this year was to accelerate product development. As a result, any company needs high-performance prototype solutions to build the best final product in a shorter lead time, and to incorporate feedback as fast as they can, with a maximum agility.

How to find the right prototype tool? Rapid prototyping technologies might be the answer for you!

Introducing Rapid Prototyping technologies

Let’s first start with the basics of rapid prototyping technologies. We’re now taking you on a guided tour of the different existing techniques.

Additive Manufacturing

Additive manufacturing, also called 3D printing, is a technique that produces objects from 3D files by fusing material layer by layer, using a 3D printer. Various additive manufacturing technologies exist such as Selective Laser Sintering (SLS) which can be used for plastic 3D printing, Direct Metal Laser Sintering (DMLS) which can be used for metal 3D printing, or Fused Deposition Modeling (FDM) also for plastic parts.

Subtractive Manufacturing

Subtractive manufacturing is a technology which uses an opposite approach. Here, layers are not added on top of each other: a machine removes parts from a block of material until the desired shape is ready. Subtractive manufacturing includes several technologies such as:

• Turning: A moving cutting tool removes material from a part which is placed in high-speed rotation.
• Milling: The cutting tool itself is placed in high-speed rotation and its cutting edges remove material from the part.
• Drilling: A cutter rotates on the part to drill holes.

Casting

Casting is a technique where you create several parts from a first model, used as a reference. This initial part is usually made using an additive manufacturing technology. Once the object is 3D printed, a mold is created around it with silicone rubber. It is cured and then removed. Afterwards, the mold can be filled with the final material – usually resin.

How to choose between Rapid Prototyping techniques

Now that you know more about the different rapid prototyping technologies, here’s our guide to help you find your way through their specificities and to make the best choice for your product development process.

Which criteria should you take into account?

There are several questions you should ask yourself when it comes to choosing the right rapid prototyping technique for your product development project:

• What level of quality are you expecting for this prototype? Is it a low-fidelity or medium-fidelity prototyping project, or even functional prototyping?
• Fidelity to the final product is also important. Do you need a prototype which will look and feel exactly like the object to be manufactured?
• The complexity of the part is essential. For a highly-complex object, you will need a highly-precise rapid prototyping technology.
• Do you need specific material properties? Like, should your prototype be flexible, or made of robust metal? This will clearly influence your choice of rapid prototyping technique.
• The desired quantity is also essential: some technologies are only effective for a small number of parts.
• And of course, your available resources are a key element to take into account. How much time do you have? And what’s your budget?

With all of these questions in mind, we’ll now review each technology to see which one is best for your product design process.

Additive Manufacturing: The fastest and cheapest rapid prototyping technique

First of all, 3D printing is the fastest rapid prototyping technology, which is quite convenient when your goal is to get a prototype quickly, right? It makes your research and development process more efficient.

Moreover, additive manufacturing is the cheapest rapid prototyping technology for small batches because it takes less time to prepare the machines for production than with other rapid prototyping technologies. And when it comes to prototyping, many times you only need small series of your parts.

But be careful with the price of 3D printing. Some designs might not be suited for this technology: if you use a very important amount of material, without hollowing your object, the cost can be quite important. Also, your 3D printing costs can increase if you wish to get a perfect surface aspect since you will have to choose some special finishing options. Thus, it’s the cheapest technique for prototypes where the aspect is not the first concern. If you need to get a preview of the final aspect, additive manufacturing might give you a very satisfying result, but it might not be the cheapest rapid prototyping technique.

If you need to create parts with complex geometries and intricate structures, 3D printing is also an excellent choice! For instance, it allows the creation of objects with impossible designs, that you could not manufacture with other prototyping techniques such as subtractive manufacturing.

Also, if you wish to create parts that are partially hollowed or with integrated assemblies, we strongly advise you to use additive manufacturing. This technology can produce these parts within a matter of hours, at a reasonable cost compared to other rapid prototyping techniques.

Finally, a great advantage of additive manufacturing is that it can allow you to create your prototype directly with the final material of your product: some of our 3D printing materials are perfectly suited for the creation of final products. Thus, you won’t have to test other materials after the rapid prototyping step, so you gain precious time in your research and development phase.

Subtractive Manufacturing: The best surface finish and highest precision

Subtractive manufacturing also offers many advantages. First, it’s the most precise rapid prototyping technology, with better tolerances than 3D printing.  Moreover, with subtractive manufacturing, you can get a very good surface finish, right away. This is great for an advanced step of your prototyping process.

But these technologies are more expensive than other techniques such as 3D printing. Indeed, it takes more time to prepare the machines for production, and this has a cost, which is especially high for small production batches.

Also, it’s quite complicated to create complex parts using subtractive manufacturing, so it’s definitely not suited for all kinds of designs.

Casting: A good rapid prototyping technique for large quantities

Casting is also a very interesting rapid prototyping technique. It can create parts with good quality and a fair level of complexity. But since you first need to produce the mold, there are many steps involved in this process, so it’s not the fastest technique. With these many steps, you might lose some accuracy, and end up with a low-fidelity prototype. So it’s not the best choice if you’re looking for a 100% reliable result.

Moreover, this rapid prototyping technology can only be used if you need a to produce a large batch of parts since you create your own mold. It would not make sense to take all of these steps for only 2 or 3 parts.

Using 3D printing for Rapid Prototyping: Which technologies and materials should you use?

When it comes to rapid prototyping with 3D printing, there are different cases that will define which material and technology you should use.

If you wish to create an early prototype, don’t invest too much in the visual quality of your material. You’re just trying to check that the shape is satisfying. So we advise you to use a material relatively cheap, not to spend too much on this step of the process. In this case, raw Nylon PA12, made with the Selective Laser Sintering technology, is a great choice.

If you need to get a prototype with a good surface aspect, you should select the material which resembles most your final material. To achieve such a result, you can add some finishing options to your prototype.

Some of our customers even found a way to make their product development process faster: they use the same material both for prototyping and for production of their final parts. As a result, they skip some precious steps of material testing. HP Multi Jet Fusion PA12 and CLIP resins are a common choice for our customers.

Moreover, don’t forget that it’s also possible to 3D print metal, which can be interesting for the last steps of your prototyping process. You can use materials such as Stainless steel, made with the Direct Metal Laser Sintering technology, for instance.

Rapid prototyping with Sculpteo’s online 3D printing service

Interested in creating great prototypes quickly thanks to 3D printing? It might not be interesting for you to purchase your own 3D printer. To avoid making such an investment, you can use an online 3D printing service such as Sculpteo, to reduce the risk taken on a financial level. You just need to upload your 3D model on our website, pick the material which suits you best, and you’ll get an instant quote!

Ready to become the next industry champion? Make your product development process faster with rapid prototyping now!