Carbon pan question

[sschering]

I'll probably make another Carbon GT pan for a 2nd GT I'm building.

Question is what is better a super stiff pan or a little flex?

The kids GT I did 3 layers of carbon. It comes out about .075" thick and while it's stiff front to rear because of the sides and braces it will twist a little side to side.
Nothing wrong with that.. it's crazy light, drives awesome and takes punishment only an 8 year old can dish out..

For the next one I was going to go 5 ply for .125" thick.. Just a touch over the 3mm you see in flat carbon pans.

Any thoughts on the issue?

[Phin]

.075 is too thin for a chassus...even old 1/12 cars were atleast . 084 thick. Most graphite chassis were 3/32 or 2.5mm. I don't know if youre already doing it but you can also layup the carbon sheets at different angles to each other to increase stiffness.

EDIT: Whoops. Thanks jwscab.

[jwscab]

3/32" or .093", not 3/16.

agreed, single chassis pan, 3/32" or 1/8". you could go on the thin side with side rails, but you are better off thicker for countersink depth for your screws.

[GoMachV]

im just gonna throw this out....I have a Bullet chassis that was laid up with a wood core and it has been cut up to where just two, 1" rails remain and it is very very stiff still. Might try a thin balsa core and see how it goes. It gives you thickness for the screws and stiffness, as well as keeps it light

[sschering]

The pan I made is 1 ply 12k twill, 1 ply 12k +45/-45 biaxial and another 12k twill.
It has carbon running on 4 axis. 0,90,45,-45. Each ply adds about .025 thickness.


It's a full pan with stock pan height walls.. not just a plate.
The walls are just 2 ply twill.. The biaxial is only in the floor of the pan.

I could do 4 ply.. 2 twill around a 2 ply biaxial core.. that should get .100" or 2.8mm

[sschering]

im just gonna throw this out....I have a Bullet chassis that was laid up with a wood core and it has been cut up to where just two, 1" rails remain and it is very very stiff still. Might try a thin balsa core and see how it goes. It gives you thickness for the screws and stiffness, as well as keeps it light

I saw that one.. Probably worth a try since I have all the materials on hand.. lots of balsa and carbon..
I do worry about delam with a wood core.

I'd like this next one to be a full pan with the 30° kick up.

I have a blue GT pan coming to use as a guide for building the plug.

I may just make a mold from the blue pan.. then it would have all the counter sinks molded in..
Down side is the smooth finish side would be the bottom and the counter sinks would be bumps on the top I'd have to sand off.

Another thought I've had is to just put the biaxial down the center band where the suspension bolts on. the wings and sides don't need all that extra weight..