The Toecutter said:
Thank you for posting this. I learned a few things while reading this thread. I will be watching this thread regularly, also to see what comes of this. It is scarily similar to what I had in mind in terms of function, but with an entirely different approach and layout.
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I thought the same thing when I read your thread. I'm just a bit too addicted to torque, I guess =)
The Toecutter said:
Milling out the faring shape you want would take a lot of work out of the project. I don't want to spend a bunch on tools and do not have access to 3D printers or mills, so I am a bit more limited on what I can do. Zote-foam is extremely light and easy for a DIY builder to shape with cheap tools. I hope folding Lexan onto a mold is as easy as it seems, because I am going to have to do such a thing for my build.
After looking at the guy that
3d-printed a motorcycle with 1.00mm single-wall PLA, that guy printing panels for his Aston Martin DB-4 recreation, and looking at the Rotovelo, I think I'll try to actually use a 3d-printed ABS fairing, not simply a core. With ~25% infill I could actually have a more rigid fairing; 80% the strength per volume, and a quarter the weight. I'll probably add some shallow internal ribs as well. The Solidworks-compatible plugin 3dPrintTech will make slicing large components simple. I won't actually model it until I build a frame, that way I will have real measurements to use. If it turns out the fairing isn't stiff enough, which would be surprising since it wont actually be weight-bearing, then I can simply lay up over it and use it as a core.
It'll need to be painted or UV-treated, however.
recumbents.com has some great info on fairing design. A lot of people stack and glue high-density foam together, then use a simple hotwire to carve it into the shape the want. Then, comes the hard part...
The Toecutter said:
Do you have any literature or info that you can share on NACA air ducts, mirror shapes, and body shapes? Before you had access to Solidworks, what information did you use in the brainstorming of your design? I once read "Streamlining and Car Aerodynamics" by Jan P. Norbye, and "Aerodynamics of Road Vehicles" by Wolf Heinrich-Hucho, and a bunch of SAE papers from my former University's library a few years ago, but have none of the items handy for reference. I used their information in the design of aerodynamic body parts for my electric Triumph GT6 conversion.
You'll find a bunch of info
here, including how to build NACA ducts. Which are kickass, by the way.
I plan on using a NACA duct with either a sliding cover, or a ramp floor that can be raised.
Only a matter of time commitment.
