The Definitive Guide to 3D Printing: Micro-precision printing

For companies manufacturing traditional parts and components, the choice to use injection moulding or 3D printing comes down to simple maths: in most cases, as production volume increases, the cost to produce each part via 3D printing rapidly begins to exceed the cost of moulding. In some applications, that crossover point happens within a few hundred parts.

That is because for most traditional parts using regular plastic, while the upfront mould cost may be high, materials are less expensive, so the cost of each part is less compared to printing. As a result, 3D printing has only made sense for relatively low-volume production runs. For larger volumes, it is more economical to build the mould and manufacture conventionally.

Where has 3D printing been adopted for production parts most widely? In low-volume or custom applications such as aerospace, medical devices and dental moulds.

For microfabrication, however, those standard rules do not really apply, and the maths is almost reversed. Why? First, because the cost to produce a mould for very small components is much higher. Second, the cost of materials as part of the overall investment in 3D printing is much smaller because the parts themselves require much less material.

As a result, even if the 3D printing materials are 10 times the cost of traditional materials, it matters less to the overall cost of producing small parts. In these instances, 3D printing can make sense for small, high-precision parts where production is in the tens of thousands. The use of 3D printing does require the purchase of a printer (or multiple printers), which can be an expensive proposition. However, the cost of those printers is amortised over time, and, unlike moulds and dedicated tooling, the printers can be used to create other parts (and even to create new moulds) without any additional investment.

Advantages of micro 3D printing

Micro 3D printing presents a number of potential benefits for manufacturers that need to generate relatively low-volume production runs of very small and very precise parts or products. Those include:

Flexibility. A 3D printer can be used to produce a wide variety of parts for different applications. Manufacturers can quickly respond to design changes, customer requirements or market conditions without the cost and complexity of creating new moulds and tooling when a modification is required.

Lower material and chemical requirements than traditional 3D printing. A significant amount of the cost of 3D printing is generated by materials requirements. The filaments are more expensive than similar materials for injection moulding or machining operations. For many standard-sized parts, users also have to print elaborate supports that can create costly waste. Micro-scale parts require much less in the way of materials and finishing/cleaning chemicals, so even printing thousands of parts presents a relatively small investment in materials.

Elimination of mould and tooling costs. The development and creation of specialty moulds and tooling for micro-scale parts is significantly more expensive than in the case of a standard-size part. And these moulds and tools can rapidly become obsolete as requirements or designs evolve and change. While 3D printing does require an equipment investment, it eliminates the ongoing need to recreate moulds and tooling. For parts that do require injection moulding approaches, the printers can be used to economically create new micro moulds as well, making them a good fit for blended operations that rely on a variety of production techniques.

While higher part counts (in the millions) at the micro-scale may not be economically feasible using 3D printing, for production runs in the tens and hundreds of thousands, micro 3D printing is an affordable option. The technology can also provide additional improvements and benefits over the long run, that further increase the return on investment.