Posted by Thomas A. Frank.
Engineer on team #121, The Islanders/Rhode Warrior, from Middletown (RI) High School and Naval Undersea Warfare Center.
Posted on 4/14/2000 1:59 PM MST
In Reply to: Egg drop help Please… posted by Travis Covington on 4/13/2000 8:35 PM MST:
: Soo…Yes its an egg drop vehicle. But theres a catch. The project is worth 80 or so points. If the egg survives you get 70 points if it breaks you get 35. BUT the thing is for every gram your device ways its minus 1 pt. SOOOO im at a loss for words. I dont know what to do. Oh and one more thing…-50pts for ballons or parachutes. hehe there is also 10+ pts for a report etc.
Let’s see if I can offer some advice, as I’ve been there, done that. You didn’t mention the height…in our case, it was out a 7th floor window of the Johnson Engineering Center (RPI) onto the concrete patio below…where a large target was placed. You had to hit it bullseye to have any chance of winning.
We had a 1 kg weight limitation, and the contraption had to fit in a box 10x10x10’ pre-launch (sounds suspiciously like a FIRST project, eh?).
I will say this, the associated rules you describe definitely make it a different contest than when I was doing it! That penalty for weight is nasty, and takes away the usual approach to the problem…which is to float the egg in a container of salt water (such that the egg is neutrally buoyant), so the shock load of the impact is equally distributed across the whole shell of the egg (eggs are amazing strong in compression, if the compression is evenly distributed across the whole shell). I’ve also seen grape jelly and a number of similar substances used (personally, I preferred Caro syrup). Did it four years in a row at college, and never had an egg break…but I wasn’t very good at hitting the bullseye. And the final year I did it, when I thought I had the solution (which amounted to an Egg bazooka, with a rocket shaped thing that extended at launch, and which had an Estes rocket motor so I could accelerate it into the ground to limit cross wind effects…the rules said we couldn’t DEcelerate the egg, nothing about ACcelerating the egg…but they wouldn’t let me light off the rocket…something about the safety of the onlookers…). But I digress.
The next logical thoughts are of course parachutes and balloons…but again, there’s a sever penalty. I wonder what the organizer is looking for? Maybe…
Since accuracy of hitting a target is not mentioned, I would take a piece of urethane packing foam - the very light weight (usually yellow) stuff that you typically find really delicate things (like glassware) packed in (you can buy it at most any sewing store, as padding for chairs and the innards of pillows, or a good camera shop as camera case foam liner), make it the maximum size allowed (if there is no size limitation, about 12’ on a side would do), hollow it out to take the egg, and drop it within this ‘block’. The fellow who did this one year at RPI was most successful in protecting the egg; however, just as he tossed it out the window, a updraft lifted the thing, and it went UP a good 250 feet more, before freefalling back on the other side of the building from where the contest was being held…no points for accuracy, but the egg was fine.
You might also consider a bunch of popsicle sticks forming a box, with the egg supported on rubber bands within the box structure.
I would not be surprised to see negative scores on this one. 70 grams is not a whole lot to play with.
Please let us know the results.