Calculating the Cost of 3D-Printed Parts

Which of these two CAD models would be cheaper to metal 3D print?

However, the solid cube presents a challenge because of a larger cost driver - machine time. 'Chunky' parts are difficult to direct metal laser sinter (DMLS) due to the internal stresses that build up in the part during the layer sintering process. They can be built, but the results may require multiple builds to dial in the machine parameters as well as additional post processing steps to get the final part within specification.

In this simple example, the solid cube is a better candidate for a machining operation, while the cross-linked design would be impossible to machine. With less material in the cross-linked design, the machine laser requires far less travel distance compared to the condensed cube. Eliminating laser travel distance results in a faster build. A faster build means a lower-cost part. Support structures are typically required so DMLS parts are effectively welded to the build plate and secured throughout the layering build up. The solid cube must be supported with many layers of support scaffolding to keep it welded firmly to the build plate during sintering. The cross-linked design does not require any self-supporting structures. This translates to a reduction in machine up time and elimination of labor tied to finishing steps required to remove the support structures.

A bottle opener at left, as designed for machining, and a bottle opener at right, 3D printed with support structures.

Here's another example of an everyday application: a bottle opener, depicted at left and below. This bottle opener was designed to be machined. When we aim to metal 3D print the bottle opener as designed, machine and finish costs are the largest contributors to the percentage breakdown of the overall part cost.

This bottle opener has been re-designed to achieve 85% part cost reduction. Features were shelled and thick cross sections were eliminated. It is lighter and functions to open a bottle with no problem. With this design, we see that less laser is required to produce this part. Less laser time translates to less machine expense. In addition, with the smaller footprint and no exterior support structures on the wings, many more of these bottle openers can be printed during one build cycle resulting in high volume efficiency gains.

Here's the bottle opener redesigned for 3D printing (additive manufacturing) at left, and 3D printed with support structures.

Cost of Setup of 3D-Printed Parts

Compared to traditional forms of manufacturing, like casting or molding, industrial 3D printing has one key advantage for designers and developers. With printing, the cost and time associated with a custom tool is completely eliminated. The cost to own a fused deposition modeling (FDM) printer has become readily and widely accessible with low cost of entry. Desktop printers can range anywhere from a few hundred dollars to around $4,000. Most operate with FDM/FFF filament materials that range from $15-$40 per kg.

Check out this cost calculatorif you are interested in learning more about costs associated with desktop printers and operation. Industrial grade machines, however, require significant investment and operational infrastructure compared to the desktop printers.

Here is a percentage breakdown of costs of printing the bottle opener as designed for machining.

For industrial 3D printers the setup costs are much higher than desktop printers due to the power required, material and build volume considerations, and parameter setup validation work required.

These machines can range in price from $20k for a small photopolymer printer to millions of dollars for a large-frame metal printer. Depending on the technology, there may be other operating costs associated with material recycling, inert gases, lasers, part washers, and safe handling operations.

Machine maintenance, calibration, and a skilled workforce are things to consider when investing in an industrial printer. Based on Protolabs' R&D experience with a large format metal 3D printer, the GE X Line 2000R, one can plan for around two months of setup and validation work taking place before the machine is ready to start making parts.