# Ideas for this fun project?

1. Dec 4, 2013

### matt2matt

Here's the project:
You have a 60x60x60cm box, and a marble (the material of the marble could be steel, glass, plastic, etc.).
There are 2 holes in the side(s) of the box that are 20cm vertically apart.
The marble must start from the lower hole with basically no velocity, and by any non-electrical means shoot out of the upper hole.

How would you do it?
What kind of simple machines / devices would you use to propel the marble?

I am doing this myself, but I am really interested in seeing what some people will come up with!

Last edited: Dec 4, 2013
2. Dec 4, 2013

### voko

If the marble has enough velocity initially, it can simply be deflected to the top hole.

If it does not, well, there must be some source of energy in the box to accelerate it.

3. Dec 6, 2013

### rkum99

Wow, that sounds interesting! Is this for a class?

Anyway, how are the holes oriented? Is the second hole directly above the first, or
is it above the first on the other side of the box. Also, do all mechanisms have to be
contained within the box? Like voko said, its really just a matter of getting the ball to
move, upon which you can add a ramp of sorts that leads to the second hole. So you
could have a lever/hammer thing that knocks it forward.

But that's boring. Currently I'm imagining some sort of rube Goldberg machine right
now, so I don't know if you care to hear it. Guess that depends on the purpose of the
project - to do it as simply as possible or just to create something cool. Anyway, more
info would help.

4. Dec 6, 2013

### matt2matt

the red are the holes.
The project requires the use of at least 2 simple machines, and 3 transformations of energy (springs, inclined planes, launchers, etc). A rube Goldberg machine is exactly what we want! The best thing to do is creatively fashion together things or use old parts from toys to move the marble.

5. Dec 7, 2013

### rkum99

Haha, the two holes right above each other make this a lot trickier...

Well for something like this, legos, k'nex, whatever building toys you can get your
hand on, will help a lot with creating stuff. You could use wood and the like, but
legos and k'nex really help with the trial/error aspect of something like this. K'nex
has many roller coaster track pieces that could be used to carry the ball easily
with some modifications. In fact, I think they have tracks actually designed for balls
as well, though they are for bigger balls...Anyway, onward to some of my ideas.

So some simple machines that can be easily implements... (These are pretty obvious,
so you probably already figured stuff like this out). You are pretty much guaranteed to
need an incline somewhere in your machine, being used as a ramp.You could easily use
a falling mass connected to a pully to directly lift a platform with the marble. Once it
reaches a certain height, the platform would hit a stopper on the very edge such that
it tilts forward (sorry about the bad descriptions). Something like this is fairly common,
so you could try something like the apparatus in this image.

http://http://scioly.org/wiki/images/1/1c/SC-springtype.gif

So essentially, a green spring is held down as a mass falls downward. As it falls, the
spring is stretched. Once the mass has reached the ground, the mechanism holding
down the spring is released, while a mechanism locks the spring on the other end.
As the spring restores itself, a pulls a string that drags a platform forward, pushing
the marble along. I have no idea how effective this would be - the stronger the spring,
the faster the marble will move. But then you would need a heavier mass to deal with
the larger restoring force. Also, construction would be tricky :P.

I don't have an image for this one, so it'll be harder to understand. Anyway, a marble
could roll down a ramp into a......spoon like extension? The extension would be attached
to an threaded axle. The velocity of the marble would cause the spoon-like extension
to begin spinning in a circle. Similar to a wing-nut, it would slowly rotate downward, like
a wing-nut would on a threaded rod. At the bottom, it would hit another ramp, upon
which the marble would roll out. Hope that makes sense!

Anyway, thats all I can think of now.....I hope I helped! :)

Edit: Realized I didn't even overview a simple system. Something pretty simple would
be a launching mechanism (Spring or falling mass) connected to a lifting mechanism
(another falling mass or an incline). From there, you can just have it roll right back
to the exit hole. Once you have that, you can stick in all sorts of other stuff.

6. Dec 7, 2013

### voko

The requirement that the marble starts at the lower hole with basically no velocity means there must a source of energy in the box. That could be a falling mass. Its fall must be triggered by the marble.

I have put together a sketch of a possible machine. See attached.

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7. Dec 7, 2013

### matt2matt

These ideas are GREAT! I really appreciate you guys' help. I'm amazed at the elegance, and they are sparking some of my own ideas, too.

I am not done yet though, so ideas are still MORE than welcome from anyone else.