Next installment of the RC Hypercar project. I go over the design of the monocoque and initial testing of the first prototype. #radio #3dprinting #motorsport
Hey, that's an amazing project, I would love to see more. I reminds me of my years in the Formula SAE in the university. I always wanted to do something similar to that but didn't find the time/motivation to start it. One idea that I have to improve the strength of the flexures is to use a thin metal strip (something like a shim with thickness based stiffness you want) as the flexible element. That way, you have also a more deterministic stiffness on the flexure that you can calculate and include it in your roll stiffness calculation. Keep this perfect content!
Thanks! That’s a great idea to use metal strips. I’ll test that out. I’ve already found that the fatigue life of the plastic flexures may not be that good. 3d printing leaves a lot of non-uniform stresses in the plastic.
Wow I love how thought out this car is. What are your thoughts and experiences with having the motors in the wheels? How heavy are they? I feel like as they are only sprung by the tire their mass has a different impact on car stability than the mass in the body, which is sprung by the tires and the suspension. Also due to the wheel mass being far from the center and the rotational inertia of the whole car being relatively small (due to most of its weight being in the center) the inertial forces of the wheels bouncing up and down could easily flip the car, right?
The motors weigh 74g each. It's definitely a compromise for the purpose of aerodynamics and individual wheel control. Compared to a spindle from one of my normal RC cars that has the bearings and stub axle, the motors weigh about double. I'm not running the car with any dampers or roll springs in these tests so I can't really get a feel for how much it affects the handling dynamics. The wheels are prototype parts as well, so they're quite heavy. I also think an RC car's tires with the foam inserts have more dampening than a full size car with pneumatic tires. So it's hard to know without mounting a sensor to the control arm. I'm not sure about the car flipping. I probably should have tried to model that. The handling without roll springs right now is very quirky (Also the battery is just flopping around inside the monocoque). I only flipped the car once by accidently hitting a pothole. I know adding the full body with the wings and everything is going to drastically change this. I have a test print for the body done and it adds a lot of mass to the ends of the car with the wings.
to hight from the ground u shoud cover the wheels cover the front and read rods use a edf fan at the bottom with skirts for up to 1.0273 times the down force to the weight so u can hang it up side down and u shoud make it from carbon fiber it needs alot more flexibility the wheels are to thin the floor needs a difuser need more agresive side pods and also wider body to control better the dirty air
There will be a full body with wings and a diffuser. I may add a fan to the car at some point. The monocoque looks higher because the sides will be part of the venturi tunnels. Next video I’ll go over the aerodynamics of the car.
I use Fusion 360 for everything. Everything is PLA right now. The front and back are two separate sections that are glued. I didn’t mention it in the video, but since the two sides are symmetrical I just design one half and mirror it as the last step.
I just used gel type cyanoacrylate or super glue. From what I've read with PLA and most plastic's it's the strongest. Someday I may print the car out of ABS or Polycarbonate in which case I can solvent weld those plastics.
