3d printing as strong as metal

I was wondering if anyone knew anything about the markforged 3d printer that supposedly prints parts as strong as metal (using carbon fiber). The reason for the question is that they said they invented a new hot end that can dispense the carbon fiber. So does that mean all we really need is one of their nozzles, and we can essentially print metal? If anyone know anything about this, I'm really curious. I can't afford their $3500 printer, but it seems if they would just sell their hot end, anyone could do it. I just think the company is thinking too small. If they could sell their hot ends and filament, it would open it up to all of us here. I'm sure most everyone would buy one.

Edited 2 time(s). Last edit at 04/22/2015 09:48AM by fatesalign.

Just kidding. read more into it and I was wrong...

Edited 1 time(s). Last edit at 04/22/2015 09:19AM by gmh39.

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greghoge.com

HUGE 3D PRINTER PARTS SALE!!!

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gmh39
It looks like they are just creating new filaments doped with the different fibers. Kinda like how the conductive filament is doped with carbon black to make it conductive.

They are also probably not using a a nozzle made from an atypical material so that they fibers do not wear down the interior or enlarge the hole as the filament is extruded.

Possibly. All I know is that the prints they've shown off are incredible. They have claimed the strength is stronger than aluminum's weight to strength.

Interesting machine. If they are using long strand fibers then I assume their print head will have to be able to cut the strand before each head move. I wonder how they match the fixed length of the fibers to the variable extrusion ratio. That seems difficult.

I will say there is more to it. It prints nylon and then carbon fiber with just one nozzle. But once again, if they could sell their nozzle, everyone would buy one.

I also just read on their site that the "magic is in the nozzle" and the filament

Edited 2 time(s). Last edit at 04/22/2015 09:41AM by fatesalign.

Does nylon take a while to cool down when printed? If so, then they are probably setting the carbon fiber strands into the nylon while it is still soft so that they stay in place, then printing more nylon over top to seal it in.

you can get carbon fiber tow (carbon fiber string) in pretty thin thicknesses. So long as you can keep the whole strand together as it is routed through the printer it seems pretty feasible from a Reprap stand point. That's assuming they are in fact inbedding the CF into while the Nylon is soft.

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greghoge.com

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No it isn't part of the nylon. They are sold separately. Also, they say they put the nylon and then the carbon fiber on top. Here is the video: [m.youtube.com]

Edited 2 time(s). Last edit at 04/22/2015 10:33AM by fatesalign.

I'm not sure. It might be. It is definitely interesting. I'd be happy to spend upwards of 200 for a nozzle.

I just watched the rest of the video. The guy said there are 2 print heads. The one that prints carbon fiber can also print fiberglass

Anyone else?

I'd agree with gmh39.

Listen to how he says it on the video - It 'melts it into the plastic layers below'
He does say there are two print heads.

To me it's a separate heated nozzle that is dispensing dry, unmelted strings (carbon, glass, kevlar) and squishing it into the plastic layers with the heat of the nozzle.
Once its stuck down, the fibre should just pull itself thru the nozzle without needing an extruder.

If it were a dual x gantry printer, the fibre wouldn't need cutting, the excess could be trimmed off after printing.
If it were just a dual head printer you'd need to think about cutting the fibre after applying it so it didn't just follow the rest of the print around.

The guy, Mr Mark, mentions 'pausing prints to drop nuts in' in the vid. There could also be some pausing and manual intervention involved in stringing the fibre that he doesn't go into.

a

Has anyone actually seen or heard of someone that has this printer other than the MarkForged?

Ya I just don't know. And how is the resin mixed? Either way, it's extremely interesting. They've already been shipping, so if anyone has one, please let us know. I'm crossing my fingers on them selling replacement parts. I'd totally get a nozzle if that's all I need.

Totally get a nozzle if you wish. I suspect there's more to it than that.
There's no resin either - that's the printed plastic.

At 3:58 "We have two heads - a nylon printhead which puts all the form around and a carbon . . . printhead which essentially melts the fabric into the part below it"

Anyone can build one. If they learn enough and put in enough development time which, it looks like Greg Mark of Markforged has done.

There was an old posting on these forums somewhere about thread/ fibre embedding in prints.

a

... reinforcing plastics with carbon fibers is a good (and very common) way to get superior stability -- but with laying it down only in horizontal strands you don't recieve uniform stability values ... this is one of the big goals many developers/companies are targeting since some ten years now!

The best stability/rigidity is achieved with woven carbon fabric, cut and seamed together, then inflated in a form/mould and impregnated with polymers.

There are some older developments around carbon nanotubes, graphene and now 'air-graphite' for generating strong 3D-structures out of ultra-rigid carbon -- tests with carbon nanotubes shows their mechanical limits like 5x the stiffness and up to 2000x the tear strength of steel fibers!

Imagine the properties of complex 3D-parts, fabbed/knitted/woven out of pure carbon, outperforming any metallic or ceramic material

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

There might be more to it. I'm just hoping not. We could actually print functioning tools. The possibilities would be pretty fantastic. Maybe I'm jumping the gun, but from what I saw, it was quite strong. I just wish someone who owned one could come here and discuss it.

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VDX
... reinforcing plastics with carbon fibers is a good (and very common) way to get superior stability -- but with laying it down only in horizontal strands you don't recieve uniform stability values ... this is one of the big goals many developers/companies are targeting since some ten years now!

The best stability/rigidity is achieved with woven carbon fabric, cut and seamed together, then inflated in a form/mould and impregnated with polymers.

There are some older developments around carbon nanotubes, graphene and now 'air-graphite' for generating strong 3D-structures out of ultra-rigid carbon -- tests with carbon nanotubes shows their mechanical limits like 5x the stiffness and up to 2000x the tear strength of steel fibers!

Imagine the properties of complex 3D-parts, fabbed/knitted/woven out of pure carbon, outperforming any metallic or ceramic material

Since it's melted, couldn't you lay it down in honeycomb pattern like any other printer? That should give it some pretty incredible strength. I've worked with fiberglass but never carbon fiber, so I'm not sure of its properties.

Edited 1 time(s). Last edit at 04/22/2015 05:06PM by fatesalign.

... the carbon fibers weren't melted - they only have this strengths as 'endless' reinforcement strands across the horizontal plane.

If used as short fibers, like in glass-fiber filled plastics, then they add much to rigidity, but only a small part to tear strength ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

i think it has 2 nozzles