When you think about 3D printing, you probably envision a thermoplastic being printed layer by layer. This is fused filament fabrication, and while it is the most common type of 3D printing, it is but one of more than a dozen types.
For engineering applications that demand metal parts, Markforged created two new 3D printing technologies: CFF (Continuous Fibre Fabrication) and Metal FFF
These technologies produce parts in composites and metals respectively and models can be designed to utilise both technologies to solve engineering challenges, such as weight reduction, complex geometries and precision fittings.
Metal FFF
Metal FFF is a 3D printing technology utilised by the Markforged Metal X. It prints parts using a high metal content filament. The parts are then washed and sintered to remove the binding agents and transform the part into a dense metal. This gives parts the strength and mechanical properties of solid metal in all directions.
CFF
CFF is a 3D printing technology used by the Markforged X7, X5 Mark Two and Onyx Pro. It prints in nylon and reinforces parts with continuous strands of a composite material (carbon fibre, fibreglass, high-temp fibreglass or Kevlar). Parts with continuous reinforcement can replace machined metal parts in various applications.
Hybrid Tooling with the Markforged Ecosystem
Utilising the best technologies available to us is crucial for solving engineering challenges and finding solutions to manufacturing limitations. This is why we have been experimenting on weight savings vs strength with Markforged technology.
A recent project saw us manufacture a gear system using a combination of Metal FFF and CFF to produce a metal and composite gear system.
Here’s the gear in all its glory:
We 3D printed the inner and outer parts in Stainless steel 17-4ph using the Metal X and we 3D printed the inner section in Onyx on the Mark Two. We used an exposed infill on the composite part to further reduce weight and material use.
The gear is 65mm and weighs 70.75g in total. It is a 100% 3D printed, digitally forged gear system made from solid stainless steel and nylon-carbon-fibre.
An equivalent metal part produced in Stainless steel 17-4ph would weigh 190g. This represents a weight increase of 168.5% over the 70.75g part. The composite part weighs 62.7% less than the equivalent metal part.
It functions as intended with the same performance as the full metal part. The only difference is our part is lighter.
No post-processing is needed for the composite part and no machining is needed for the metal part. The metal part only needs sintering before use.
The cost to produce the part was around £16.50 in materials. By bringing together the Markforged ecosystem of software, hardware and materials, we were able to significantly reduce the weight of the gear while maintaining the strength of a full metal part.
Overall, this project was a resounding success. Gears up!
