Mechanical Engineering Project, Need A Creative Mind

[yb1013]

Mechanical Engineering Project, Need A Creative Mind! Please Help!

Ok well I think I've figured out what I am going to do for my project, but I just need a little help to finish it off.

So the idea is that there is a semicircle fountain/pond and we have to build an object that will get an orange from one side of the fountain to the other. You cannot just go straight through the center of the fountain however because there is an inside barrier that would stop you (think of it like a track). The challenge is to get the orange there in the quickest time possible. You also cannot use remote controls, so it would definitely make it very hard to control when going around the semicircle.

Now, my idea is to have a sturdy platform with a steel plate at the bottom (acting as an anchor) so that it will just stay in place at the beginning of the race. Then I will have a crossbow aimed towards the other side of the fountain (45 degree angle) that will shoot the orange into the water residing on the opposite side of the fountain.

Now, the only problem is that I am not allowed to technically set it off for the shoot once the race starts. So I am going to have to time it somehow to shoot off in a few seconds. I thought maybe of lighting a string as a fuse and maybe finding a way to work like that??

Idk, I'm kinda stumped at this point, anybody have any ideas please?!

 

[Danger]

How about just using a water-soluble substance for the safety device. An Alka Seltzer with a couple of holes drilled through it for string anchorage works pretty well.

 

[yb1013]

hmm, so your saying like use alka seltzer to hold the strings back?

The only problem with water soluble is that the point of the platform is so that the crossbow won't dip into the water. So the alka selzer would take a long time to let go if its not getting wet..

 

[yb1013]

does anybody have other ideas to offer?

 

[Danger]

So the alka selzer would take a long time to let go if its not getting wet..

I misunderstood the situation. If it's not going to be in the water, a simple clockwork mechanism should suffice.

 

[yb1013]

I misunderstood the situation. If it's not going to be in the water, a simple clockwork mechanism should suffice.

oo alright, but how does the clockwork mechanism work?

could you please give an example of how would use it, because I really don't know how to make a simple design that would fit this situation.

Thank you

 

[Danger]

The easiest way, which I used a lot when I was a kid, is just to get a mechanical (not electric) alarm clock. Tie your trigger string around the alarm (not time) winding key and set the alarm. When it goes off, the key unwinds quickly, reels in the string, and you have your trigger activated.