Avanine-Commuter - 8-11-2006 at 18:24
Hi!
I've already googled it; I've found a few models that WOULD work if I was allowed to use rubber bands, but unfortunately I'm not.
So basically I have to drop an egg from a two story building.
I get graded on:
creativity
how light it is (the lighter the better the grade)
how big it is (the smaller the better the grade)
If the egg is broken or not (If it breaks you lose a lot of points)
My materials:
Boba straws
tape
glue (hot glue gun)
string (cannot be outside the straws, only allowed to string through the straws to connect them)
I have unlimited supply of each material. I can only tape the ends of the straw 1/4 in. in, so I can't just wrap everything in tape. Does anyone have
any suggestions for models?
And no, I cannot use anything else; no insultations or bubble wrap.
THanks for the help!!
bereal511 - 8-11-2006 at 18:32
I had to do this at my science camp too. But these materials seem so limiting 
.
I wonder if it would be possible to build a sort of parachute device by gluing together the Boba straws into something like a rectangular sheet of
straws, make a straw sack to place the egg in (several layers of straws for maximum strength), then attach the straw "parachute" to the sack using
tape that's rolled into sort of a string type material.
Hopefully you're allowed to cut the straws, so that you can mold them around the egg. If it seems a bit confusing, you can IM me for a picture of it.
Avanine-Commuter - 8-11-2006 at 18:42
Wow I appreciate the quick reply!
Sorry I was unclear on a few certain rules:
Yes you may cut the straws
No you may not glue the straws on their long-sides. Glue and tape may only go 1/4 in. into the edges of the straws.
String and tape cannot be hanging loose for a parachute.
Thanks for any other suggestions!
The_Davster - 8-11-2006 at 20:23
Did one of those once, did not have a size limitation though. I suspended the egg in the centre a a half metre square cube made of straws. Rubber
bands and string held the egg in the centre of the cube.
I imagine it could be scaled down a bit.
Or arrange the straws such that when it hits the ground the first thing that hits the ground it the end of a straw. Like a hedgehog of straws around
the egg.
dapper - 8-11-2006 at 20:36
suspend the egg inside of a structure like fullerene. c60. geodesic dome... make a sphere.. itll absorb some impact. support the structure with straws
12AX7 - 8-11-2006 at 21:19
How many straws do you get?
Align the straws parallel to the surface, make it a reasonably regular shape like a dodecahedron or buckyball or some other bastardized semi-spherical
shape. Put down a good bunch of layers. The idea is to store impact energy in squashing straws on the side. Bending them is too hard (and being
long beams, they flex rather easily once buckled) and axial loading is too stiff. Put in something good to reinforce the egg's shell, or else dampen
it further (some creative use of rubber band suspension could definetly be interesting).
Imagine, say, a cubic foot of straws bunched together (similar to they way they are boxed and sold, but without the box). Put your egg in the center
of this. As long as it's crushing from the lateral (i.e. not axial) dimension, this will work very well. If any position is necessary, a sphere like
this will work nicely. If position can be selected, then a relatively small mat can be made to heavily cusion the impact side (with due regard for
center of mass while falling) and thinner armor on the other sides for when it bounces and inevitably rolls over. If you are limited in straw use,
then you'll have to figure out exactly how much you need to cusion and some creative strategy may be necessary, e.g. more open framework.
Tim
Avanine-Commuter - 10-11-2006 at 15:20
Thanks for the suggestions!
I would like to try to do a suspension thing where the egg is suspended through string in a sphere of straws, but the problem is we are not allowed to
have loose hanging string, and so the egg MUST be secured by straws. DOes anyone have an idea to get around it?