CBR250R Vetter style aero mods

[low&slow]

The coroplast doesn't bend that well and is much better for straight panels. The sign paper is weather resistant, bends easily and is great for the curved portions of the structure. 1"x 3/4" wood lathe is light , rigid, easy to attach with glue and screws. I also used some bamboo for x-bracing and just hot-glued it into place. I tested the new tail today and it works great. The only modification I'll need to do is add another attachment from the tail structure to the MC frame as it as tipped downward slightly. I run another tank and see how much improvement there is with the new tail.
I'll post some pictures on my build thread. Let me know if you additional info.

[euromodder]

Originally Posted by low&slow

The coroplast doesn't bend that well and is much better for straight panels.

Do you score it on the inside of the bend to make it bend better ?

[sendler]

That's what I was thinking too. Use a dull knife to fold in the inner surface between each rib with a score mark. How long will Coroplast hold up to weather and sun? Does it expand and wrinkle in the sun?

[low&slow]

I use a heat gun for gentle bends in the coroplast. I would avoid scorng the coroplast as it would reduce its stiffness and strength. Thats why the coated sign paper iworks so well. The coroplast is very durable in the weather and can last for years, no problems with expansion, shrinking or wrinkling.

[sendler]

I played around with some coroplast last night. It can be bent in one direction but you have to actually slit between the ribs on the inside and it still tends to be uneven. Also, while I was washing off the dirt from the piece that has been kicking around in my garage, I noticed that it expands enough from spraying hot water on one side or the other to make it warp. Don't know if the sun would ever make it wrinkle but it seems like it could. Luckily, my local race car supply shop sells .025" aluminum in 3x8' sheets for a mere $19. So it looks like my tail will be shiny.

[Electictracer]

I think aluminum sheeting is an often over looked medium to work with. It is strong, can be corrosion resistant, easy to cut and bent, and most importantly light. If it’s good enough for airplanes, it’s good enough for hyper milling vehicles. Compound curves are difficult without the tools and most importantly the experience to use them, but this is often easy to design around. You can probably build it completely out of sheeting if you do it right, with bulkheads.

Any way I’m biased so this might not be a very objective comment.

[bschloop]

Aluminum sounds like a great idea. you might want to try going straight to the supplier for your sheeting though. They should have a "drop rack" where they sell the stuff with dings in it that they can't sell to companies, and it's really cheap, if they have what you are looking for that is.

[sendler]

$.75 per square foot. He is selling me .025 aluminum cheaper than plywood.

[bschloop]

That's really good. I guess you'd probably pay the same at the factory, but you are getting a slightly better product. He's really giving you a deal.

[Grant-53]

I use cereal box cardboard to make 1/4 scale prototypes of compound shapes for fairings. This translates to 4mm coroplast full scale in stiffness. I use .015" Lexan for slot car bodies and it is quite flexible. Coating the aluminum with a coat of resin or plastic would help the denting somewhat. We use plywood laminated between aluminum or melamine for railcar panels. Check into paper model techniques for getting the shapes you want.