Rocket Cars
From HeatSync Labs Wiki
Contents |
Synopsis
This project will involve creating a set of rules and guidelines for HSL-sponsored Rocket Car races (fiascos?).
Examples From the World Around Us
- http://blog.makezine.com/archive/2010/04/rocket_powered_car_races.html (where the idea was sparked)
- http://www.rocketcarday.com/ (better videos from the same event Make picked up on)
- http://www.instructables.com/tag/?q=rocket%20car&sort=none (slew of 'ibles surrounding rocket cars)
- http://www.maximum-velocity.com/rocket_cars.htm (simple design, and available for purchase. Specifically, note how the car has eyehooks *on the bottom* for the string-track.)
Parts
Car
- A model rocket engine
- Typically, a C6 engine is used.
- Whether or not to use an engine with an ejection charge is up for debate. On one hand, not having a small explosion at the end is safer, but we could have a lot of fun watching cars inadvertently explode :)
- A car or some other wheeled vehicle
- In the cheapest and jerry-rigged fashion, a Hot Wheels car and a zip-tie were used.
- In a more elegant and creative fashion, custom vehicles are designed.
- Pinewood Derby cars might be a good place to start.
Track
- Guides
- Single Guide-wire
- This allows the cars to stay on a straight line.
- If the car is imbalanced or too small, it can spiral around the wire.
- Double Guide-wire
- Prevents spiraling while the car is in motion
- Adds extra friction and ability for the car to jam, if a car's connectors aren't aligned properly
- Guide Positioning
- Side(s)
- Works for both single and double guides
- Probably the best layout for double guides. A single on the side encourages barrel rolls
- Potentially limits the width of the car (lane size notwithstanding)
- Top
- Usable with single/double guides
- Limits the height of the car
- Bottom
- Certainly a more "traditional" track feeling.
- Requires minimum ground-clearance
- Helps eliminate the chance of rolling/spinning when using a single-guide, if the wire is taut.
- Side(s)
- Material
- Wire. Durable, fairly rigid, and won't burn up from the exhausts
- String. Cheap, easily replaced. Flammable.
- Single Guide-wire
- Mounting
- 2x4 start and finish lines
- dirt cheap, and easy to work with
- L-Brackets for suspending the guides
- metal, sturdy, easily attached to 2x4s
- Doubles as a blast plate at the starting line
- Eyehooks
- Small, cheap, easy to tie things to.
- Does nothing to contain exhaust at launch time.
- 2x4 start and finish lines
- Eye-Candy/Extras
- Photogates
- tied to a computer, can provide data regarding velocity, acceleration, accurate time trials
- Finish Line Sensor
- Simple set of switches to indicate 1st, 2nd, 3rd places. Arduino, small tactile pushbuttons, and some LEDs would easily accomplish this.
- Photogates
Launch Mechanism
- Requirements
- Need a way to fire off multiple rockets simultaneously.
- Make Volume 20 had a "Mega Launcher" from a boyscout troop. Pops 10 at a time (or individually) Schematics: http://makezine.com/20/megalauncher/ (Nate has all the parts to make this. consider 'em donated!)
- Need a way to fire off multiple rockets simultaneously.
- Extras
- A digital countdown timer would be sweet
- The Mega Launcher has a countdown buzzer, I believe. A digital clock could easily be inserted
- A digital countdown timer would be sweet
Rules
- Use Common Sense
- If it looks unstable and unsafe, it probably is. Participants should decide as a group if a questionable car should race or not.
- Test your car, first. A simple track can be built at home pretty easily.
- 3 Wheels
- In order to qualify, a minimum of three wheels must be on the ground a majority of the time. Bumpy asphalt can cause cars to jump and bounce, but it should be pretty obvious if a car is out of control
- One Engine
- No tandem or multi-stage engines, period.
- Car Size/Weight
- This is up for debate. The prior rules pretty well dictate how cars should be built. (Nate's opinion is "anything goes.")