i would choose carbon fibre hands down every time unlike alloy cf can flex with impact and retain its original shape whereas alloy is bent with a weak spot for life
Thanks for posting some false info to direct the creator of this thread in the wrong direction. CF, doesn't matter how it is layered, is a very stiff and brittle material that cant sustain an impact. Quasi-Isotropic carbon fiber is great for chassis plates and stuff like that that see torsional and longitudinal forces because it is 3 times stronger than its aluminum counterpart. It is terrible for things such as arms where a brittle material will not sufice. Other types of Bi-directional CF only have longitudinal strength, so they are not the best material (actually terrible) for a chassis plate, and also for other parts. I think you guys are talking about molded CF, which will not hold up in high impact areas such as the suspension components. Unless of course you drive at 10mph on flat ground.
Putting on my flame suit…
Carbon … for the most part… has no business being in an off-road RC car. Sure… something like a radio tray may be OK… but not a chassis. The 10th scale guys figured this out 10 ~ 15 years ago. Associated released a carbon pan for the RC10T… and guys would split them on the first good hard hit. (and they were expensive) And if you built a control arm out of layered Carbon … then it would be heavier than an alloy part. Team Losi has the right idea. You lay chopped carbon fiber in a mold… and you impregnate it with nylon instead of epoxy or polyester resin. So you have the durability of your standard plastic part, but the added rigidity of a non-directional carbon mat.
Now… carbon fiber side frames in my RC heli are great. They are light and VERY rigid… but they will explode if I crash. Where the aluminum frames may survive a crash. They will be bent… but they will be reparable.
Lastly… there was a statement about aluminum getting weak when it bends, and carbon doesn’t. Well… that’s just not true. Yes… any metal as it’s bent will “Work Harden.” Thats why as you bend a piece of metal back and forth, it will eventually snap. (on the molecular level, it’s the reason forging works) But if you heat the bent metal close to it’s melting point… then quench it in oil… you will get close to the same hardness as you started with. (actually, it can be harder, but that’s for an other post) Carbon fiber sheet… once it’s bent… will never be the same. If you flex it with any force… you WILL start to break the carbon fiber weave in the mat, and in turn, weaken the part. Sure, if you don’t fracture the resin, the part will return to it’s original shape… but it’s still not as rigid. Oh… and forget ever repairing it. Once you’ve severed the mat… it can be glued together… but you don’t have the strength of the carbon at that point anymore.
OK… that got too long… but I had to make my voice heard on something that is expensive, and not very good for what we would use it for.
I will say this in favor for carbon fiber… it dose have the nice “Bling” factor. And for an on-road car… it can help save weight.
Good post, but it is not taking into consideration the different grades of CF out there. Quasi-Isotropic CF is perfect for chassis plates, and other parts that take non-direct impacts. In a Chassis application Quasi-Isotropic CF can be 3 times stronger than its aluminum alloy counterpart. In an application such as suspension arms, CF is terrible as it is brittle when asked to sustain direct impacts, and will shatter.
i have ordered cf from this place http://graphiteelegance.com/ . its not the glossy stuff but it cheap and its made well. he will make what size u want. i ordered a 12"x24"x.100" sheet for like $60 a while ago.Great info! I think the FG carbon chassis is around 4.5mm. If I can get one for a good price (Less than a new chassis) then I'll go for it.