The Markforged Mark Two is a 3D printer for serious design and engineering applications. This industrial-grade desktop printer can 3D print parts with a higher strength-to-weight ratio than 60 61-T6 aluminium.
If that sounds incredible, then prepare to be utterly amazed because not only will the Mark Two print parts 27x stiffer and 24x stronger than ABS, but it will do this cost-effectively and with unparalleled consistency too. We have seen first-hand how the Mark Two can revolutionise design and engineering environments; we have seen snap-fit joint prototypes be printed in under an hour and we have seen engineers replace their their CNC and milling operations with this fantastic 3D printer.
Markforged Print Process
The Markforged Mark Two 3D printer uses a patent-pending Continuous Filament Fabrication (CFF) print head alongside a Fused Filament Fabrication (FFF) print head to 3D print parts from nylon with continuous strands of composite reinforcement. The FFF print head is dedicated to printing nylon while the CFF print head is dedicated to printing composite.
The Mark Two is capable of printing both anisotropic and quasi-isotropic ply constructions for different levels of reinforcement. Part performance is largely determined by the types of material used in the part and the ply design. However, part design, end-use conditions and build conditions also come into play. Which is to say, to get the most out of the Markforged Mark Two, every stage of the print process has to be meticulous.
Parts printed with the Mark Two do not require post-processing. They can be used fresh from the print bed so prototypes can be tested straight away. You are also not forced to print with a composite; you can print with just nylon if you like.
Markforged Materials
The Markforged Mark Two can reinforce nylon parts with three different composites. The Enterprise version (more on this below) can also print high-temp fibreglass. Here’s what you need to know about Markforged materials:
Nylon: Nylon is the core build material of the Mark Two and Mark One 3D printers. Nylon is a strong and durable material ideally suited to functional parts, such as living hinges and snap-fit joints. The tensile strength of Markforged Nylon is 53.8 MPa with a tensile strength at break percentage of 260, while the flexural strength is 32 MPa. Parts printed with Nylon are strong and durable, but they become even more so with one of the following materials:
Carbon Fibre CFF: Carbon Fibre CFF has the highest strength-to-weight ratio of all Markforged materials, and it also has the highest thermal conductivity. In third party tests, parts printed with carbon fibre CFF have been shown to be up to 30x stronger and 30x stiffer than similar parts printed in ABS. Carbon Fibre CFF has a tensile strength of 700 MPa and a flexural strength of 470 MPa with a tensile strength at break percentage of 1.5.
Kevlar CFF: Kevlar CFF has the best abrasion resistance and the best impact resistance of all Markforged materials. In tests, nylon parts that are embedded with continuous strands of Kevlar CFF have been shown to be up to 5x stronger and 20x stiffer than similar parts printed in ABS. Kevlar has a tensile strength of 610 MPa and a flexural strength of 190 MPa with a tensile strength at break percentage of 5.5 and a compressive strength of 97 MPa.
Fibreglass CFF: Fibreglass CFF has the highest strength-to-cost ratio of all Markforged materials and it is also electrically insulating. It is the best all-rounder, with good strength properties and a low cost making it ideally suited to prototyping. Fibreglass CFF has a tensile strength of 590 MPa and a flexural strength of 210 MPa with a tensile strength at break percentage of 5.5. It also boasts a higher compressive strength than Kevlar at 140 MPa.
To show you just how strong parts can be, here’s a video of a Carbon Fibre CFF chain link breaking at 22,000 lbf:
Markforged Mark Two Models
There are three different Mark Two models to choose from. These are:
1. Standard – The Standard model can print nylon, fibreglass and carbon fibre only;
2. Professional – The Professional model can print nylon, fibreglass, carbon fibre and Kevlar;
3. Enterprise – The Enterprise model can print nylon, fibreglass, carbon fibre, and Kevlar and high-temp fibreglass.
The Enterprise model has a special extruder that can print materials with a heat deflection temperature of 140°C.
All Mark Two models are shipped with a significant amount of material. With the Standard moel you get 1000 cm3 of nylon and 50 cm3 of fibreglass; with the Professional model you get 2000cm3 of nylon, 200cm3 of fibreglass, 100cm3 of carbon fibre and 100cm3 of Kevlar; and with the Enterprise model you get exactly the same and 3 sets of extra nozzles.
With the Enterprise model you also get more security and admin features, such as two-factor authentication and an admin portal, and you also get access to new features before everybody else.
Markforged Mark Two Applications
With the ability to 3D print parts with a higher strength-to-weight ratio than 60 61-T6 aluminium, the Mark Two is ideally suited to creating functional prototypes and end-use parts such as snap-fit joints. For example, printed composite parts can often directly replace aluminium machined parts. This also has a huge cost advantage; it would cost just £30 to print a snap-fit joint with the Mark Two, but it would cost around ten times that to machine that same part from aluminium.
Markforged Mark Two Specifications
– Build Size: 320 x 132 x 154 mm;
– Technology: FFF/CFF;
– Materials: Nylon, carbon fibre, fibreglass, Kevlar;
– Layer resolution: 0.1mm;
– Software: Eiger, a browser-based software;
– Dimensions: 575 x 322 x 360 mm;
– File types: .STL;
– OS support: Windows 7+, Mac OS 10.7 Lion+ and Linux.
Image credit: Image 1, Image 2, Image 3,
