Material can be most anything but it has to be made correctly. It's not that hard to do, I just rebuilt my wood motor mount that I screw to the old plastic firewall. I built it in about an hour late one night so I could mount a brushless motor after I fried the original esc. I had to go float flying again the next day. I'm sure with proper tools and materials you could do a much better one in a few hours.
I've also used some sort of cardboard fibre-ish stuff that came from the bottom of a cheap set of drawers. It cuts, holds and feels a lot like ply, but seems more durable. Unfortunately I'm misplaced my stock of it so I can't take a photo... But I did use it for my p51 and funbat builds that are somewhere in this forum topic...
I am just getting into this hobby and I am curious as to what I should use for the firewall. I have access my laser cutters here so I can build my own but I just can't seem to figure out what is the best material to use.
What do the flite test guys use, plywood? What are the dimensions, i.e. thickness and ply count?
The Only info I can remember from past videos is that the FT guys use 3/32" aircraft grade plywood. Not sure what type. I really would like to find some but haven't been able to get any at the LHS, they only have hobby grade plywood. I was able to get some stronger plywood at Michael's but it was a little thicker. I may have to go back to that since I can't find any.
I just went to Michael's and found the birch plywood at the same thickness 1/8" (labeled 3mm), it's a little thicker than the FT stuff, but it's 3 layers of sandwiched ply, I've actually taken the softer outer layers and kept the inner harder layer for control horns on previous builds. I'm making landing gear brackets for my anycopter hex out of them and will see if I keep it full thickness or not. I may also wick some CA if needed for strength as well.