Sometimes Simple Is Best
Additive manufacturing and 3D printing can truly build impressive parts, but impressive can mean many things. Oftentimes you will see pictures or samples to demonstrate very intricate or precision features. Surface finish is another area that is often demonstrated in sample parts.
With the Markforged continuous fiber system, we can do all that, but where the system really shines is strength. This can be a hard one to demonstrate with a basic sample piece. However, Markforged and East Coast Additive have a super simple stick the size of a key fob that really does a fantastic job of conveying what a fiber embedded part can become.
The sample fob that we make at ECA is a small stick; 14mmwide, 70mm long, and only 3mm thick! That is less than 1/8th inch thick. This small piece is built in Markforged Onyx material which is a nylon with microscopic carbon fiber blended in. It is a very capable material by itself, but the real magic happens when we embed a continuous fiber. The dual head Markforged printer uses a second print head to inlay a CONTINUOUS strand of carbon fiber on each print layer that we specify.
There are materials with chopped or short strands embedded in the raw filament but the continuous material really binds the part together and dramatically enhances the material properties. We also lay each layer of continuous fiber at a different angle than the previous layer which builds up a mesh matrix giving the part strength in multiple directions. Our sample stick is printed in a 45 minute build cycle on one of our Mark Two printers.
So now we have this small and unassuming part, but what do we do with that?
Simple: hand it to somebody.
Intuitively everyone wants to grab it with two hands and give it a bend and that is when the lightbulb goes off. The rigidity of the part and the preconceived notion of printed part clash and it is clear that this is some thing different.
I usually have a keyring full of various materials to speak to and the carbon fiber embedded piece is far and away the strongest. CF embedded onyx parts rival 6061 aluminum in strength and outpace it in flexural strength. So it is immediately clear that this is not your nephews PLA print.
If I am being honest, it was this same moment that convinced me that the Markforged system would be the centerpiece of our printing operation and allow us the flexibility to meet customer needs.