Can you help with a science/engineering project?

[skymama 37]

The assignment: Make a working roller coaster no longer than 2m long. It must contain 1 loop and 3 hills. Use whatever you want to run down the course (they chose a marble).

My son is doing this as a group project. We are trying to keep costs down. They tried using Legos for the supports and poster board for the track (they folded up the sides to keep the marble in) but Nick said the Legos kept falling over. They were at someone else's house, so I didn't see what they did. I think Legos should work...maybe just make a larger base? It has to be something they can carry into school.

Any ideas for different materials or where to put the loop compared to the hills is greatly appreciated! We have to go away this weekend for a soccer tournament so it's really cutting into the time available to mess with different materials. Thanks!

She is Da Man, and you better not mess with Da Man,
because she will lay some keepdown on you faster than, well, really fast. ~Billvon

[kingbunky 3]

if they're willing to sacrifice the lego, a few drops of glue will help keep things together. i imagine that if they were building tall thin towers it wouldn't take much for them to snap and topple.

"Hang on a sec, the young'uns are throwin' beer cans at a golf cart."
MB4252 TDS699
killing threads since 2001

[cocheese 0]

plastic tube(pvc/vinyl) and coat hangers for support.

[turtlespeed 226]

Quote

plastic tube(pvc/vinyl) and coat hangers for support.

That's what I was thinking - also - for the track they can use 1/4" copper - soldered together. That way they can adjust it "just" right.

Off to work -

I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

[cocheese 0]

Cut a length of vinyl tubing and bend it to do the required loops etc. drop the marble and adjust where necessary. Buy a lot more than you need. Make cuts and stuff if necesssary. use duct tape to rejoin it.

[turtlespeed 226]

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Cut a length of vinyl tubing and bend it to do the required loops etc. drop the marble and adjust where necessary. Buy a lot more than you need. Make cuts and stuff if necesssary. use duct tape to rejoin it.

Ooooh Duct tape - forgot about that one.

Gotta have duct tape or it just ain't right.

I know a metal fab shop here - we could make it out of stainless.

I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

[huka551 0]

I imagine that the slopes would have to be pretty steep to get the marble around the loop...don't you think?

Muff Brother 3723

[turtlespeed 226]

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I imagine that the slopes would have to be pretty steep to get the marble around the loop...don't you think?

All a function of how long it has to build up speed - and how tight the loop is - of course there is a "bell curve" but for the most part - even a shallow angle can produce the speed needed, given that the surface that the "coaster" is riding on is smooth enough.

I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

[skymama 37]

Quote

That's what I was thinking - also - for the track they can use 1/4" copper - soldered together.

That sounds expensive!

What area in Home Depot would have vinyl tubing?

I don't have wire hangers. Didn't you see the Joan Crawford movie?

She is Da Man, and you better not mess with Da Man,
because she will lay some keepdown on you faster than, well, really fast. ~Billvon

[cocheese 0]

No. One steep drop 1 1/2 - 2 times the length of the loop and three small hills at the end. The tube already has a nice natural bend to it.

[DJL 235]

Garden hose would make a good track if the diameter is right. Try using a lead 50 caliber ball for a blackpowder rifle. You can get them at most Walmarts. Throw in a little math: kinetic and potential energy .

"I encourage all awesome dangerous behavior." - Jeffro Fincher

[turtlespeed 226]

15 - 18 dollars for what you would need.

Vinyl is available - even - i think - at Wal-Mart - the same stuff you hook up your icemaker to.

I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

[skymama 37]

Wouldn't a garden hose be too heavy for Legos to hold up?

Turtle...are you talking about something in gardening, plumbing, small tools or what? Super Wal-Mart is huge!

She is Da Man, and you better not mess with Da Man,
because she will lay some keepdown on you faster than, well, really fast. ~Billvon

[DJL 235]

The support would have to be different, something stiff enough to hold the floppy, winding hose in place. Liter soda bottles filled with water? Cheap and portable, they could refill them at school.

"I encourage all awesome dangerous behavior." - Jeffro Fincher

[davedlg 0]

Cheap, lightweight and easy to construct is half paper towel / toilet paper rolls. You can make cuts near the top of half rolls to get them to bend. For support, I would use either balsa wood or even rolled up paper in an A-Frame, suspending the track underneath. You could use a styrofoam base to get the supports to stick and hold well.

I would put the loop first followed by the series of hills. The marble will have to start on the top of a hill which is higher than the overall height of the loop.

[wartload 0]

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***
What area in Home Depot would have vinyl tubing?

I don't have wire hangers. Didn't you see the Joan Crawford movie?

The plumbing area should have clear vinyl tubing, or clear reinforced vinyl tubing that would be less likely to collapse. They should sell both of them by the foot. I'd personally get the reinforced and use a marble or a large ball bearing. You can still see through the reinforced stuff enough to track the marble, but I think it's less likely to "pinch".

There's also a plastic toy set called "marble run" that is like legos, but is intended to make stuff of this sort ... may be cheaper to use the tubing, though. I second the idea of using something like water-filled plastic containers as stands ... and duct tape. The purpose of something like this, if the teacher has a grain of sense, is not to see who can make something lovely or expensive ... just functional.

[Slappie 9]

got to Toys'R'Us they sell Hotwheels tracks with loops and hills. Has all the supports you need and even the vehicle. Build it...

Then copy it with whatever materials you want. Go cheap, spensive whatever.

"Find out just what any people will quietly submit to and you have found out the exact measure of injustice and wrong which will be imposed upon them."

[monkycndo 0]

I helped out with something like this before. We taped the tube to a piece of cardboard laying flat. Just stand it up and drop the marble in. It is very easy to adjust the shape and slope of the track. The only concerns are where the loop crosses over itself and to make sure you don't make the loop so tight that you compress the tube out of round. Either buy the tube bit larger then the marble or make a nice smooth loop. I agree to have the loop first and then the hills. Takes the most speed to get through the loop. It is stable and easy to carry, just takes a couple end supports taped on the back that get turned 90 degrees and the thing stands up by itself. You can color/decorate the cardboard to make it look like an amusement park.

Hope this helps,

Monkeyboy

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