The Fiber continuous carbon fiber 3D printer [Source: Desktop Metal]

In a surprise announcement, Desktop Metal announced a new thermoplastic 3D printer, the Fiber.

This is quite surprising to me, as the company’s entire history has been solely focused on the development of accessible metal 3D printing technology. They have so far released the Desktop Metal Studio system, an inexpensive, office-friendly unit that is capable of producing metal parts.

That product was targeted at those who were unable to afford the very high price of traditional large-scale metal 3D printing options, which often require installation in environmentally-controlled workshops.

They subsequently announced plans for releasing a huge production metal printer that happened to use a different metal 3D printing process. That device has yet to hit the streets, but again, it’s a metal machine.

Then this month Desktop Metal announced a desktop 3D printer they call “Fiber”, and its claim to fame is the ability to 3D print with continuous carbon fiber.

Carbon fiber is an incredibly strong material, and is often found in 3D printing in the form of composite filaments containing tiny chopped carbon fiber segments. While these carbon fiber-reinforced filaments are indeed significantly stronger than plain old filament, they pale in the face of actual continuous carbon fiber that leverages strong molecular bonds for significant distances.

To date there are only a couple of 3D printer manufacturers that offer the ability to embed continuous carbon fiber within a 3D print, two being Markforged and Anisoprint. Each of these companies offer devices equipped with a different toolhead that can spool out and cut carbon fiber that would typically be laid within a print to add strength along the most appropriate axis.

Automated Fiber Placement

But it appears that the Desktop Metal Fiber device may be doing something slightly different. The company says it is doing a form of Automated Fiber Placement (AFP), which Wikipedia defines as:

“Fiber Placement is an automated composites manufacturing process of heating and compacting resin pre-impregnated non-metallic fibers on typically complex tooling mandrels. The fiber usually comes in the form of what are referred to as “tows”. A tow is typically a bundle of carbon fibers impregnated with epoxy resin and is approximately 0.500 in wide by 0.005 in thick and comes on a spool. Fiber placement machines (FPM) generally have a capacity of 12 to 32 tows or when placing all tows at a time in a course, have respective course widths of 1.5 in to 4 in. The tows are fed to a heater and compaction roller on the FPM head and through robotic type machine movements, are placed in courses across a tool surface. Courses are generally placed in orientations of 0°, +45°, -45° and 90° to build up plies which in combination, have good properties in all directions.”

Desktop Metal Automated Fiber Placement

Desktop Metal calls their process “μAFP”, or “Micro AFP”. It’s not entirely clear how this works, as their competitors typically lay a few strands through the center of printed parts, whereas Desktop Metal’s specifications for the Fiber HT model indicate “up to 60 percent continuous fiber loading with advanced matrix”. Does that mean a part could be made with 60% carbon fiber?

Continuous carbon fiber tape? [Source: Desktop Metal]

It also seems that they can deposit multiple layers of carbon fiber tape in different directions to optimize strength.

Even better, the continuous carbon fiber could be combined with 3D printable material (the “matrix”), which could be a variety of high-power engineering materials like PEEK, PEKK, Nylons and more. These material combinations should enable production of absurdly strong parts that offer significant other engineering properties.

Interior of the Fiber continuous carbon fiber 3D printer [Source: Desktop Metal]

The Fiber 3D printer handles the materials through the use of a “robotic tool changer”. I take this to mean that they have up to four different toolheads stored in a kind of garage within the device, and the robotic system attaches a toolhead to the single motion system. The presence of four toolheads offers the possibility of multiple materials, or different types of fiber within the same print job.

Desktop Metal Fiber Models

Desktop Metal offers two models of the Fiber, an HT and an LT version. The HT seems to be able to produce the highest quality parts with “less than one percent porosity”. Both machines seem to have a rather large build volume of 310 x 240 x 270 mm.

Desktop Metal Fiber Pricing

The two devices will apparently be available in spring 2020, but the unusual aspect is their pricing. They are sold with a “hardware as a service” pricing model. Essentially you pay an annual fee for use of the device, somewhat similar to what Carbon does for their equipment. The HT is priced at US$5,495 per year, while the LT is priced at US$3,495 per year.

The question for me, however, is why Desktop Metal took this step. The Fiber, while being a powerful 3D printer, is quite outside their normal scope. I can think of two reasons why the company might pursue this angle.

Desktop Metal Carbon Fiber Strategy

First, it may be that in the course of interacting with the metal 3D printing clients they have learned of a significant demand for this type of product. Having access to those clients already essentially provides for an instant market to sell the devices. If there’s a business, an entrepreneurial company like Desktop Metal will jump on it.

A second possibility is competition with their main rival, Markforged. With the introduction of the Fiber, both companies market now similar devices in both metal and continuous carbon fiber materials.

Via Desktop Metal