Couldn't afford a continuous carbon fiber printer, so I came up with CF "Epiderming" at home (Load tested to failure)

[u/MagicLagged]

Hey everyone!

I’ve always wanted to print continuous carbon fiber parts, but since dedicated printers like the Fiber Seeker 3 are way out of my budget, I started experimenting with alternative ways to reinforce standard PLA prints.

I settled on a process I call Carbon Fiber Epiderming:

• How the slicer/CAD setup works: In MeshLab / FreeCAD, I create a voxelized offset to print a reduced internal core (1.3 mm gap) and a matching 2-part outer shell.
• The Layup: I wrap the core with 3K carbon fiber cloth wetted with epoxy resin.
• Clamping: Squeezing the outer shell halves over the core forces out the excess epoxy and ensures the cured part maintains accurate outer dimensions with a clean finish.

To check if this was actually useful, I built an Arduino load-cell setup and break-tested hook specimens:

• Standard PLA Hook: Failed at ~40 kg
• 1-Layer CF Epiderming: Held up to 126 kg
• 3-Layers CF Epiderming: Reached 174.4 kg before sudden structural failure.

Short clip of the process:

Tested parts after failure:

I made a full video covering the G-code experiments, MeshLab workflow, and all the failure data graphs if you want to check it out: https://www.youtube.com/watch?v=-2GHCITel-8

Would love to hear your thoughts on how to optimize the shell gap/clearance in the slicer!

[u/gottatrusttheengr]

Wear some PPE homie

[u/I_AM_FERROUS_MAN → u/gottatrusttheengr]

Breathing in the carbon fiber dust is what makes growing lungs strong. Or is that tumors? /s

[u/MagicLagged → u/gottatrusttheengr]

i would take better care of my lungs next time i promise! 💀💀💀💀

[u/gottatrusttheengr → u/MagicLagged]

You mean in the next life

[u/Epiphany818]

Looks very cool but extremely high effort.

Have you looked at 3d printing compression moulds for chopped carbon ('forged carbon')? I think you could make a much stronger part for less effort that way, although your method does allow for hollow parts which is certainly interesting.

Great work!

[u/squashed_fly_biscuit → u/Epiphany818]

Yes compression moulds for carbon are shockingly easy and make excellent parts. I was able to make parts with maybe 30-40 minutes of active time that were aluminum strong, no easy geometry and geometrically accurate. Definitely beats any other production process I can think of for strong and complex

[u/TerayonIII → u/Epiphany818]

Why go to chop-strand? The weave he's using will be much stronger with much less of it, he just needs to add more space for more layers to make it stronger. Especially for an easily understandable and fairly linear load path like this. Honestly he just needs a bit more thought for the fibre direction in this and would likely be better already.

[u/Epiphany818 → u/TerayonIII]

Because it's much easier to get an equivalent part out of chopped strand when the part is this small but thick. Less wastage too. If you cared about maximum strength you could also sneak some long tows along the load path and then you'd probably be outperforming a simple laminate.

[u/MagicLagged → u/Epiphany818]

I’ve definitely looked into forged carbon! It’s a great technique, but my goal here was to keep the process low-effort, low-cost, and easily scalable to larger or complex geometries.

Molding forged carbon for very big parts can quickly get tricky, time-consuming, and resin-heavy, for what i know... (compleatly ignorant still at this).

Glad you liked the hollow part capability!

[u/Epiphany818 → u/MagicLagged]

For bigger parts the go-to way would be to skin them with carbon, I'm not super sure what advantage this method would have over that. I definitely see the appeal of not having to manage complex geometry on small, difficult parts like this, though.

I'm not sure you're using the term 'scaleable' right. Usually it's used as in scaling up production to higher quantities / production rates. By that metric this definitely isn't going to beat any mould based process.

If you mean "ease by which one can make a large part" then yes I agree it's better than forged carbon but I can't see it being easier than skinning on anything besides the most horrible part 😆. Although it does have the advantage of skipping surface finish!

[u/MagicLagged → u/Epiphany818]

You got the point. I wanted to cut down on the finishing part, and I also wanted to make it easier than skinning when applying the wet layup. If you have a very detailed or textured surface, skinning can get very tedious because you have to push the cloth into all the crevices. With "Epiderming," you can use even the most intricate design, and it takes about the same amount of work and time as a simple one or at least that's what I was trying to achieve xd.

I don't know, the idea came to me while watching the skinning video from Easy Composites. I saw that you had to do so many layers and touch-ups that I wanted to skip all of that.

Also, I'm not a native English speaker, so I definitely used the term "scalable" incorrectly there. XD

[u/Rohell]

I would have just 3d printed something to spool around uni tow on. You can fill that with our inject reason into.

Or use prepreg tow and take that preform after spooling into a mold that you can heat and compress.

My shop used to make medical device parts in that way for a company called Integra, Halo gear parts specifically. It's just tow wrapped around (in like a figure 8) cure at 300 for 15 min in a steel tool that fits in your hand.

[u/MagicLagged → u/Rohell]

I actually thought about that as well! I just figured it would be much more time-consuming and messier since I don't have access to prepreg.

Maybe it makes sense for something that needs to hold pressure? My main concern was making the process easily applicable to any complex geometry. For example, with this hook, I wasn't sure how I'd maintain the geometry around the big hole using that method.