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. https://reprap.org/forum/read.php?1,500260,500260#msg-500260 Thu, 16 Apr 2026 13:58:22 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,500260,557480#msg-557480 Re: 3d printed carbon fiber https://reprap.org/forum/read.php?1,500260,557480#msg-557480 arnab05 General Sat, 12 Sep 2015 20:18:37 -0400 https://reprap.org/forum/read.php?1,500260,500459#msg-500459 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500459#msg-500459
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 ...]]> VDX General Wed, 22 Apr 2015 17:53:11 -0400 https://reprap.org/forum/read.php?1,500260,500443#msg-500443 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500443#msg-500443
Quote
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 (:P)
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.]]> fatesalign General Wed, 22 Apr 2015 17:05:46 -0400 https://reprap.org/forum/read.php?1,500260,500442#msg-500442 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500442#msg-500442 fatesalign General Wed, 22 Apr 2015 17:02:59 -0400 https://reprap.org/forum/read.php?1,500260,500441#msg-500441 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500441#msg-500441
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 (:P)]]> VDX General Wed, 22 Apr 2015 17:01:24 -0400 https://reprap.org/forum/read.php?1,500260,500438#msg-500438 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500438#msg-500438 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]]> alan richard General Wed, 22 Apr 2015 16:51:09 -0400 https://reprap.org/forum/read.php?1,500260,500385#msg-500385 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500385#msg-500385 fatesalign General Wed, 22 Apr 2015 14:41:21 -0400 https://reprap.org/forum/read.php?1,500260,500382#msg-500382 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500382#msg-500382 cdru General Wed, 22 Apr 2015 14:30:08 -0400 https://reprap.org/forum/read.php?1,500260,500370#msg-500370 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500370#msg-500370
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]]> alan richard General Wed, 22 Apr 2015 13:56:38 -0400 https://reprap.org/forum/read.php?1,500260,500361#msg-500361 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500361#msg-500361 fatesalign General Wed, 22 Apr 2015 13:34:20 -0400 https://reprap.org/forum/read.php?1,500260,500312#msg-500312 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500312#msg-500312 fatesalign General Wed, 22 Apr 2015 11:16:11 -0400 https://reprap.org/forum/read.php?1,500260,500299#msg-500299 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500299#msg-500299 fatesalign General Wed, 22 Apr 2015 10:30:47 -0400 https://reprap.org/forum/read.php?1,500260,500298#msg-500298 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500298#msg-500298 m.youtube.com]]]> fatesalign General Wed, 22 Apr 2015 10:28:28 -0400 https://reprap.org/forum/read.php?1,500260,500291#msg-500291 Re: 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500291#msg-500291
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.]]> gmh39 General Wed, 22 Apr 2015 10:11:02 -0400 https://reprap.org/forum/read.php?1,500260,500276#msg-500276 Re: 3d printed carbon fiber https://reprap.org/forum/read.php?1,500260,500276#msg-500276
I also just read on their site that the "magic is in the nozzle" and the filament]]> fatesalign General Wed, 22 Apr 2015 09:27:00 -0400 https://reprap.org/forum/read.php?1,500260,500274#msg-500274 Re: 3d printed carbon fiber https://reprap.org/forum/read.php?1,500260,500274#msg-500274 JamesK General Wed, 22 Apr 2015 09:23:31 -0400 https://reprap.org/forum/read.php?1,500260,500272#msg-500272 Re: 3d printed carbon fiber https://reprap.org/forum/read.php?1,500260,500272#msg-500272
Quote
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.]]> fatesalign General Wed, 22 Apr 2015 09:17:59 -0400 https://reprap.org/forum/read.php?1,500260,500267#msg-500267 Re: 3d printed carbon fiber https://reprap.org/forum/read.php?1,500260,500267#msg-500267 gmh39 General Wed, 22 Apr 2015 09:14:33 -0400 https://reprap.org/forum/read.php?1,500260,500260#msg-500260 3d printing as strong as metal https://reprap.org/forum/read.php?1,500260,500260#msg-500260 fatesalign General Wed, 22 Apr 2015 09:00:52 -0400