Choosing a Fabrication Method (Prototyping vs Mass Production)

May 5, 2024

As technologies evolve, we see an increasing number of different ways to fabricate our products. From CNC machining to 3D printing, sheet metal fabrication to injection molding, we are spoilt for choice when it comes to the methods available to us. With so many options, how do we choose which is the best method to use?

The ideal method often depends on what the part is going to be used for. Is it for prototyping or mass production? Prototyping often involves low volume production and requires a short turnaround time as you iterate quickly. Mass production on the other hand often looks at lowering cost per piece with a high quality finish. Knowing this, let us take a look at what are the common fabrication methods available to us and see where they can be applied.

3D printing is one of the fastest evolving technologies. Becoming popular in the 2000s, it became one of the best methods for prototyping. While 3D printing uses both plastics and metals, plastics are often preferred due to their lower cost. There are a wide range of plastics to choose from depending on the application. Additive manufacturing takes little to no time to set up, making it cost efficient when producing low quantities. More often than not, your part will be ready in a day or two. It is great for prototyping, where you can print a few iterations overnight and test them all the next day.

Another benefit of 3D printing is its ability in fabricating complex geometries that are not achievable using CNC machining. For example, structures with undercuts or intricate internal geometries, or parts made with generative design are usually very difficult to produce via CNC machining, or extremely expensive to do so.

On the other hand, 3D printing is often not preferred for mass production due to a lack of consistency and speed. While 3D printing might be faster for low-volume production due to the lack of set-up, the time taken to make the part itself is quite long, spanning from a few hours to a whole day for 1 piece. While there are printers optimised for mass production, the technologies are still developing, thus they are often costly. For mass production, 3D printing is possible, but we should expect longer lead times and a slightly higher cost. Often the choice to use 3D printing in mass production is based on whether the geometries are so complex that using traditional methods is not feasible, or if 3D printing can eliminate multiple downstream processes.

3D Printing

One of the most popular and well established methods of fabrication is CNC machining. It has been an industry standard for years and is one of the most reliable methods of fabricating a part. With advancements in machining techniques (such as adaptive machining) and in the machine tools (synchronous multi-axis machining) themselves, CNC machines are great at producing consistent, high quality parts with high speed and cost efficiency. While CNC machines might be more costly to set up initially, having lots of parts fabricated from it means that this initial cost is spread out, giving you cheap and high quality parts.

While CNC machining is still used for prototyping, you can expect much higher prices per unit due to the set up costs. The lead time is often also longer as setting up and sourcing for small quantities of material takes a while. Without a large quantity to spread out the cost and time, CNC machining is often not ideal for prototyping. That being said, it is still a good way to obtain a high fidelity prototype nearing the end of your ideation phase for a product. It allows you to have a real feel of how your end product will look and feel.

CNC Machining

If your metal prototype consists of thin walls and can be made from sheets of metal, you could consider sheet metal fabrication. Sheet metal can also be easily welded, bent and stamped to produce the desirable shape in your prototype. Typically, sheet metal prototypes would be more cost effective than using traditional CNC machining.

Another great way to mass produce plastics is by injection molding. Because the same mold can be used over and over again, it produces great consistency, each part being near identical to one another. While the cost of making a mold is high, being able to reuse it indefinitely means that the extra cost per unit will be spread thinly, similar to CNC machining. This of course comes with the caveat that it is not great for prototyping if you are not sure of the final product. While changing the mold is possible, it would be very time consuming and extremely costly. Thus a method like 3D printing will be better for prototypes, while injection molding is more suited for the mass production of your final product.

When choosing a method, it is important to take into account your design and purpose. With so many options, Factorem can help you get quality parts in a short amount of time. From prototyping to mass production, we got you covered. Upload a part today at app.factorem.co and let us support your fabrication processes.

Thank you for reading!