Replacing aluminium with carbon fibre part

[JimBear]

I am thinking of replacing an aluminium part (2 mm thickness, bottom plate for a car build) - with carbon fibre (or Kydex). 

From what I've read (very much a non-engineer!), carbon fibre seems more rigid at the same thickness (but lighter). I was thinking the carbon would have more flex at a given thickness. The Kydex, I've less of an idea. 

Does it need to be thicker than the aluminium, or can I keep the carbon at 2 mm thickness?

 

[Mo Powah]

You could even go thinner, around 1.5mm. It is strong stuff. 

 

 

 

[KILLorBE]

It depends...

The carbon plates of a few of my cars all have a thickness of 2mm (Top, bottom and damper stay,) my F103 however has a bottom plate of 3.2mm and a top plate of 1.6mm.

It also depends on your goal, there are always trade-offs, a stiffer/more rigid car isn't always desirable as it will put more stress on other parts... but it's not as simple as that.
As the car is somewhat lighter because of the carbon it will exert a little less stress on other parts, but it may also be a little faster, and as a result put more stress on those parts.

Personally I would stick with 2mm thickness, even though I don't know what car it's for, but it probably makes things easier.

[JimBear]

Thanks both of you, @Mo Powah and @KILLorBE. It's just a test, for a (very distant) future "build your own car from scratch". I think I am going to make one bottom plate out of carbon and one out of Kydex to compare, using the 2 mm thickness and see what's what. It's for an onroad car (outdoors, tarmac). 

[Mouc-RC]

Hey Jim,
A good friend of mine made a Blackfoot "racer" with Kydex. In my eyes, it's much more sexy than carbon fibre

https://rc-vintage.com/viewtopic.php?t=27569

(Sorry it's in French, but you don't need to translate the pictures )

[JimBear]

2 hours ago, Mouc-RC said:

Hey Jim,
A good friend of mine made a Blackfoot "racer" with Kydex. In my eyes, it's much more sexy than carbon fibre

https://rc-vintage.com/viewtopic.php?t=27569

(Sorry it's in French, but you don't need to translate the pictures )

Oh la laaa ... I am not going to embarrass you with my almost-non-existent french, but that was a fine example of some Kydex put to good use! ORV and Kydex, that's a good match. I think. I'll save that for the future. 

[JimBear]

I've been turning this about a bit in my head, and then I remembered I have some 2 mm Kydex that I bought for another project. It's white but I could use it for as a test piece. Just need to put it on the to-do-za list and actually get to this project, too ...