Carbon Fiber parts, interest?

Spiller1327 said:
I didn't mean to say carbon is brittle, just that a diff. cover is a good application for it. Where did u work or learn your composites Apollyon.
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Did you mean isn't a good application? I tend to agree given that there are better, cheaper, easier materials to use for that specific application.

I worked for Fiber Materials in biddeford. If you aren't familiar, they design composite materials for military applications, things like rocket nozzles and heat shields for re-entry vehicles. They actually have a heat shield that is going to be entering the Mars atmosphere on the next rover mission. I regularly got to pick the brains of some of the engineers, who where also gearheads, about this very topic.

Spiller1327 said:
I still don't understand what you are saying about wet and dry carbon.
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I think the terms he is using is refering to wet carbon as infused or something that is laid up and the resin slathered on just like the fiberglass you would use on your car. That would have a very high resin content or %. Dry is usually refering to pre-impregnated sheets that have fiber and resin all ready to go, nothing else is needed. This usually has a very low resin content and because of this is "generally" the lighter of the two.

 
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I did mean to say not a good application. You hit the nail on the head apollyon. Exactly what I was gonna say. My instructors won't let us hand lay carbon it needs to be vacuum infused with epoxy or its not nearly as reliable. I am hoping to work at Hodgdon Yachts after school on their military spec boats.

 
Hey Spiller & Ray, I don't suppose you guys took the Pre-Engineering Electrathon/Composits class at Foster Applied Technology center? Perhaps under John McDonald? He is one of the greatest carbon fiber and composites experts that I have ever met. I actually worked on the Gen 2 Mt. Blue electric cars. You guys probably got to work on Gen. 3 or Gen. 4 since I graduated in 2001. I also got to drive the Gen. 2s in 2 races, Louden & Beach Ridge in 2000 & 2001. We built 3 or 4 of the Gen. 2 cars total. Incedentally I was the one that crashed the car that was painted flat grey at beach ridge. Some of the guys that worked on the car a few weeks before had over torqued the bolts on the Carbon Fiber/Nomex Rims that we built. I made it about 35 to 40 minutes in to the race and suddenly both wheels folder over sideways in the first corner. The car fell on to its belly and I spun out and off the inside of the corner. Mc.D was pretty mad that the last set of carbon fiber wheels had been destroyed because we could not make more, it was discovered that the special light weight filler we used for the center of the hub to fill the nomex was considered Toxic and innapropriate for use by High School Students. I still raced at louded on the spoked rims though, and we took 2nd overall and 1st in the High School Series IIRC. The guy that beat us was the one that always helped out the Falmouth kids... Mike Lewis I think his name was? That might be a ways off. His car looked like a 3 wheeled carbon fiber corvette.

 
Also, I don't know if anyone mentioned it already but I don't think that carbon fiber by itself is really thick enough to keep it from flexing. You should probably use Nomex or Balsa to stiffen up the areas that need increased flex resistance without significantly increasing weight since nomex gives it volume but its hollow, so doesn't weigh much. Same goes for balsa, once its infused with vinylester or polyester or epoxy resin depending on application, it gets a lot stronger. I remember having a sample piece of nomex with dual layers of carbon and kevlar fiber on both sides and I beat it for an hour with a hammer before it finally gave it, a little, ha ha. We also experimented with other composits, but pretty much went with the Carbon/Kevlar over Nomex or Balsa combo. Aluminum, despite our efforts, doesn't stick well to composite materials.

 
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Also vaccume bag it all the way, and don't wet-lay the materials in a large mold for an important part. Always infuse it dry bag, that way its less messy, less resin is used and the part looks professional and high quality. Not like some piece of messy, hairy, sticky fiberglass crap. The vaccume that you pull on the inside of the bag will pull the resin in by itself, no additional pump necessary. The pressure of the atmosphere pressing on the bag with force it in to the carbon cloth and any other porus light wight composite materials you are infusing. If remember right NASA and companies like lockheed go so far as to infuse the parts under the pressure of multiple atmospheres in a pressure chamber and heat it in an autoclave oven to speed up curing and increase strength.... Damn, its time for me to shut up, I keep thinking up stuff to say about this.

 
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Both me and Ray took his course. We didn't build any cars because he kind of changed the course outline to better fit the composites outline. I really enjoyed the course and all he taught us, Mc. D knows his stuff. All the stuff you are saying is spot on.

 
I talked to him earlier this year, he said he was thinking about building a solar car and having that be part of the class and wanted to have something to show the kids as an example, I told him I have 3 20ft solar arrays in my back yard and a skystream 3.7 wind turbine. He seemed interested but I have been busy and we haven't talked since.

 
so im bringing the carbon fiber thread back from the grave cuz i was wondering how hard it would be 2 make CF light pod kits. 2 pods, each with 2 lights like this

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Since your not trying to save weight fiberglass would be a better application for Light pods. That wouldn't be that had you'd just have to make each side individual since they're different. If I was still at my old high school I'd totally make a set for u man

 
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