Launching a Penny Accurately - Advice Needed

[newtonsmac]

Greetings fellow smart people.

I am looking into making a device that can accurately launch a penny 0.0m to 10.0m quite accurately. I do not know whether I should a siege projectile launcher such as a catapult or trebuchet or something using compressed air. I want to try to make this out of common household stuff and recyclables but I probably will have to buy a few things from a hardware store. I don’t want it to be dangerous and I am willing to spend a lot of time and patience on it.

I myself am interested in air, but then again I have no idea how to make one without using compressed CO2 or a bike pump. I want it to be made with a home made compressor.

Trebuchet and catapult are fairly simple but aren’t that original. If you guys know of any other mechanisms that can launch a penny accurately please let me know or tell me which one I should use.

Thanks a lot.

 

[Danger]

Welcome to PF, Newtonsmac.
You might want to start with something simpler and cheaper, such as a ramp with an adjustable spring.

 

[newtonsmac]

how would you adjust the spring accurately?

 

[Danger]

Just connect the front end (for an extension spring) or the rear end (for a compression spring) to a threaded rod which protrudes through the case. An adjustment nut can then be turned to move the rod in and out. Calibration would be by trial runs, with notes taken of the position required for a particular distance.