Automated Launcher: Launching 4m & 50g Projectiles

[Daruki]

i'm trying to build a launcher that automatically launches after a period of time. it has to launch 4m and launches a projectile weighing no more than 50g. what kind of mechanisms would i need to use?
thanks!

 

[russ_watters]

Welcome to PF.

There are boundless possibilities here. Can you give us more information on your requirements and your ideas?

 

[Daruki]

Basically, it's mounted on a car. The car and the projectile together cannot be bigger than 40 cm by 30 cm by 25 cm approximately.
I don't really have an idea right now, but I've heard electronic fuses work. It has to have a high degree of accuracy.

 

[Fish4Fun]

OK, you need to give us more information:

Are you launching vertically or horizontally?
Are you launching a projectile from your car?
Is the car moving during the launch?
Do you have a "target"?
Can the project include IC engines, batteries, springs, compressed gasses, etc, etc?

You have utterly failed to define the problem in such a way that anyone can help you. If the object is simply to move a car 4M as precisely as possible, I would use a stepper motor with a uController. Similar "Science Competition Projects" define similar project goals, but with very narrow parameters for power source and control mechanisms.

Fish

 

[Daruki]

Okay, here are more details.
I'm planning to design a car that travels to a destination, stops, and then launches the projectile sideways to the left relative to the car itself. The projectile launcher must use only gravitational and elastic energy, must activate after the car reaches its destination(give or take 10s) and must shoot straight, sideways to the left 4m.
No electronically designed mechanisms, except for the timer, but as of yet, I have no clue as to how to set one up.
There is a target, which is basically a target similar to the game "Darts", where the middle circle is the most accurate which also endows the highest mark.

 

[Danger]

If the car has some kind of stopping mechanism such as a wall or an arresting cable, as opposed to just coasting to the proper area, I would use that mechanism as the trigger for the launcher.

 

[Mech_Engineer]

How about an hourglass? Or a water timer? Spring and flywheel? There are a lot of mechanical ways to do it, and many electrical ways to do it as well.

 

[carsy7]

Hey I'm new to PF, so be gentle if my first few posts aren't gold.
Assuming the car stops on impact...
Have a spring or elastic that releases its stored energy upon impact of the car via quick-release mechanism. From this, you could calculate the stored potential energy and use that to determine the initial speed of your projectile. By altering angle of elevation and height you determine the optimal trajectory to launch the projectile 4m. Hopefully this is on the right track to a solution