r/CarbonFiber

I used PETG-CF when 3D printing the frame for this infinity LED dodecahedron I recently created. Carbon fiber was the perfect choice for both its strength and its matte, premium finish to encase the 540 LEDs which are reflected into infinity.

Iam exited to hear what engineers?manufecture here think.

I am a Body Shop Mechanic trying to get into any kind of Motorsport or Additive Manufacturing business. To build out my portfolio and practice on a larger scale I decided to 3D scan my Go Kart last year and turn it into a one-off carbon fiber show-Kart. Today marks the day I am finally finished with the project (for now) and I am happy to present to you: the carbon fiber GoKart!

Wrapped by the amazing @sexyout on instagram

I plan on bringing the kart with me every time I go to the track, as a sort of Guerilla marketing campaign.
Whether or not I will ever drive it like this… remains to be seen but the curiosity is killing me!

I’d love to have your thoughts and input on the whole project and feel free to ask me questions.

My instagram is @blauwasser_racing if you’re interested in my other projects. Next I plan on making a full carbon fiber e46 bodykit - small teaser in the last image!

Chopped carbon, and epoxy, no clear coat or post polish//cleaning. Made on a resin mold, and processed in a headed hydraulic press.

A follow-up to my previous thread. As per a suggestion there, I blowtorched my carbon tube to determine the true nature of the layers (thank you so much for this advice, it worked amazingly well).

As one can clearly see, my original request of the manufacturer, which was "0-degree (longitudinal) in all layers except the very outer layer, which should be 0/90" was NOT what I was given.

Now, the fact that I'm not getting what I asked for is its own concern, but I have at least determined that it's not the end of the world, since I have now also blowtorched previous batches I have received, and they are identical, which means all the strength testing I have done previously is still applicable to this batch. The tubes have performed well. And it seems like perhaps mostly 0-degree fibers would have sucked anyways?

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So a new question arises: is this a good layup? Should I bother telling them to do it differently? As far as I can tell, it works well for my application, but I'm wondering how much more strength/weight I could be getting without losing some of the "toughness" of the hoops and 0/90s.

For context, these tubes are about 21" long, 29mm OD (~1.15"), 1mm wall thickness, and they fit together like tent poles. The direction of the force is primarily longitudinal compression. Do you guys think that, given these circumstances, this layup is close to optimal already?

A couple of videos showing the tubes in action, so you can understand the forces at work:

https://www.youtube.com/watch?v=ih3FQw-j66o

https://www.youtube.com/watch?v=eBpAHqe993c

I ordered a batch of CF tubing requesting that all the layers be 0-degree fibers except for the outermost layer, which I wanted to be 0/90. The tubing is 1mm wall thickness and 29mm OD, for a bit of extra context.

Today I wanted to confirm that the layers are as I specified, so I took a knife and delaminated one of the tubes into 3 sloppy pieces (bottom is the innermost layer, middle is the middle, and top is the outermost layer).

The *bottom* piece in the picture is the innermost part, which means it should definitely be 0-degree at this point. However, that looks like 0/90 to me (red circled section). I know that 0-degree cloth often has some 90-degree fibers just to kinda hold it all together for layup, but would that appear this way when it's cut/delaminated? Or, maybe I'm just seeing resin weaved through and it's giving me the illusion of 0/90 fibers?

I don't have enough experience to know what 0-degree looks like post-resin, so I'm hoping someone could offer some insight.

Also, what's up with the 90-degree fibers that are clearly visible in all 3 pieces? Does some "0-degree" cloth come with a fine layer of integrated 90-degree carbon just to add a bit of crush resistance?

Any insight from those more experienced would be appreciated.

I want to make my own carbon fiber parts for an ebike like in this video. Could somebody explain or link a video on how to make molds like this based off the original parts? as I cant find any info on this specific process.

Any suggestions and tips are also appreciated

Hi all, the clear coat on this carbon fiber was peeling very bad. I watched a few videos specifically for m3/m4 carbon fiber roof restoration and they said to use lacquer thinner to remove the resin from the weaves before painting. After a little sanding, I did this on this part and before I could finish, I had an appointment for an oil change at a nearby dealership. The car was at the dealership for maybe an hour. I told the dealership not to run the car through the car wash but they did anyways. The roof now looks like this. The white part is where I used the lacquer thinner. How can I fix this?

I removed my stem for the first time, to change stack height, and noticed these scratches, one of which looks a little deep. There is no movement when pressing, no feeling of loose fibers, no cracks inside the steerer either. Does this mean it's just cosmetic?

the wind blew my bike over yesterday and i’m so sad, first bike is before i did anything , second and third is after i polished it , if i took it to a paint shop could they make the blemish disappear?

I am actually so confused right now. This hasn’t happened to me before I just sanded 801,000 1500 2000 3010 compound buffed and hairdryer it dry maybe it was to hot and there were some traps solvents that just popped out because the clearcoat layer got so thin and more maybe that it pushed through. I can’t really figure this out because these little bubbles are raised not like air pockets I sanded into it’s like they came out of the surface very confused right now. Should I I’m like almost down to the carbon and I did sand into the carbon in one spot so I do need a little bit more clearcoat, but not sure as this happened to anyone?

Hi there,

this is my very first look into carbon fibers. Please be kind, if I make obvious beginners mistakes.

I'm looking into making a new carbon end cap for a motorcycle exhaust, as these parts can not be purchased in EU anymore. At least I couldn't find a single shop with this part in stock. There are shops in UK, but due to Brexit, it's very expensive to import this part (> 140 Euro plus taxes).

I did some research on how I could solve my problem:

I guess I will prototype a good fitting part with an fdm 3D printer. Then I will have to make a mould and then use this to make the final cap.

My problem is, that I cannot find a resin with a maximum operating temperature, that seems viable: According to AI, I should use a resin with at least 180 °C, the more the better. But the highest temperature I could find, was 160 °C.

I haven't decided by now, if I will try a compression mould with chopped fibers or wet laminating with a household vacuum bag.

Are there any suggestions on this specific problem?

1. High temperature (>180°C) suitable resin for compression moulding chopped fibers?

2. High temperature (>180°C) suitable resin for wet laminating?

3. Should I even try to make this on my own?

4. Do you have experience with lower temperature ratings for carbon parts on motorcycle exhausts?

Best regards from Germany ✌️

Went a lil to crazy with the clear coat rushing to get it done and build up layer to cover weave texture and I guess I trapped some solvents in the clear what do you guys recommend sand it? More clear? It’s been 24hrs since I sprayed a lot and I really did like 15 passes stupid but whatever this is my only part I need to fix it

Hi.
Wanna share my first contact with carbon.
My seatstay failed due to impact. Professional repair shops wanted a lot of money for repair so i thought it is time to learn more about carbon.

There is not a lot of good resources on the internet how to repair bicycles. Most of repairs are road bicycles where people uses 2x2 twill rolling tube around.

For the repair i used:
80g UD carbon for 0 and 45 degrees and 90g plain for final 360 layers.
Epoxy el2 from easy composites and shrink tape

I was using trick with fake prepreg wetting carbon in between the plastic foil. It was much cleaner and better fiber epoxy ratio then wetting on part.
Also it helps prevent shifting carbon on part.

Post curing was done in a cartoon box with a heater and temp. Regulator for 6h.

Then sanded down, adding xcr epoxy, sanding, 2k gloss painting.

It was already tested on downhill tracks and is doing fine.

What i did wrong:
- did not protect rest of the part, leaving epoxy mark which cannot be easily cleaned.
- it is not perfectly flat. I should add more layers directly on the narrower part of repair.

After all I am very happy of repair because it looks quite ok and what is most important working perfectly fine.

Gloss painting is used instead of black paint as i am proud of repair and would like to keep it visible.

Let me know your thoughts.
What can be done better etc.