Amazing & Graceful Egg Drop Contraption

 by wkl
IMG_3044.jpg
clip_image002.gif
Recently my AP Physics class was assigned the egg drop project. After experimenting with a few designs I found one that works very well and looks good too.

Although some of the restrictions for the classic egg drop project vary, some of the same prinicples found in this design might be applied to your own device.

The winner for our competition was determined based on the highest P-score. Where the P-score is equal to the below equation (h being the maximum height survived, m being the mass in grams and V being the volume in cubic centimeters). I think my device ended up with a score of about 430 (more than four times the second place score).
 
Remove these adsRemove these ads by Signing Up

Step 1: Materials

IMG_3050.jpg
The materials I used to create my device:
2 toilet paper rolls
1 manila paper folder (any kind of thicker paper would work just as well)
5 yakitori skewers (long thin sticks)
2 straws
ziplock bag
some thread (optional)
tape

Tools:
hot melt glue gun (not totally necessary but helpful)
x-acto knife (again not necessary but helpful)


anthony190255 says: Feb 27, 2013. 12:15 PM
lol
csbrocket3 says: Dec 11, 2012. 6:03 PM
Thank you for your help! Amazing! :D I am making a Rotor egg drop device for Science Olympiad so this helped a bunch!!
xxepicxgamerxx says: Feb 23, 2012. 6:13 PM
ummm you only used four yakitori sticks in this picture and i dont know if we need 5 or 4of them
luigithehoverboardinventor says: Jun 18, 2011. 9:14 AM
that kind of paper was inventend in our country,philippines
kacee3 says: Apr 22, 2011. 8:39 AM
I'm confused. Do we need 3 toile rolls? I cut my first roll length wise and then put the other one inside of it and taped them together... but do I need another one to cut in half??
dancer101 says: Mar 13, 2010. 9:24 AM
Thank you so much for creating this! Its amazing! it totally works and is super easy to build. I have to create one of these for my 9th grade Physical Science class and we have to drop it off of our stadium. We also have to write a paper on the laws and forces that are acting on the vehicle...got any ideas?
marty109 says: Nov 24, 2009. 6:05 PM
have any clue about what the weight was?
MissNanners says: May 9, 2009. 4:41 PM
I have done this design, but with smaller rectnagles, and my contraption is spinng crooked and all over the place, also, instead of skewers I used straws, could this be the reason? And, is there a better number of blades, like 4 bug ones, or 8 smaller ones?
wkl (author) in reply to MissNannersMay 9, 2009. 7:21 PM
hmm. Perhaps the weight isn't evenly distributed? if the straws are bending then that's a problem. You'll want to find something that can support the drag created by the blades. Also make sure that your rotors are all at a 10 to 15 degree angle (from the horizontal). As for the number of blades, you basically just want to create as much drag as possible while keeping a good spin going. I found eight worked well but you can certainly experiment with fewer.
MissNanners says: May 3, 2009. 4:25 PM
I have a few questions.
*MY limit for size is 12inX12inX12in....so what would I need to alter
  • Do the rotor blades actually move? Like spin..isn't that the point?
*I am not allowed to use skewers, so what could be replaced?

Thanks....perfect for what I was lookin for...
wkl (author) in reply to MissNannersMay 3, 2009. 5:17 PM
The whole device spins not just the rotors. So if you can't use skewers you can just glue or find some way of attaching the rotors at an angle. Maybe you could cut slots in the tube for the blades to fit in. The angle of the blades maybe an important factor. My belief is that you want the blades as close to horizontal as possible while still getting nice rotation. 10 to 15 degrees from horizontal is probably best.

For the size constraints.. actually my 30cm cube constraint is almost exactly the same as your 12in cube one (30cm = 11.8in). So my dimensions should work perfectly for you.
hithere12 says: Apr 29, 2009. 2:21 PM
How many grams is thatt?
wkl (author) in reply to hithere12May 2, 2009. 1:35 PM
sorry i forget.
kaylakat says: May 1, 2009. 6:11 PM
could you give me an estimate of fall time.
wkl (author) in reply to kaylakatMay 2, 2009. 1:34 PM
Sorry I have no clue about the time. I do know it easily survived a 5 story fall and seemed to maintain the same speed meaning that it could probably sustain any fall as long as it keeps spinning in a vertical orientation.
uguy says: May 25, 2008. 11:10 AM
I have to wonder, how many eggs are wasted in the numerous egg drop competitions such as this. PEOPLE ARE STARVING OUT THERE AND WE WASTE EXTREMELY NUTRITIOUS EGGS. Shame.
Patrik in reply to uguyMay 25, 2008. 7:23 PM
Eggs are what - about 15 cents each? The goal of this exercise is *not* to break the egg, but I assume a few presumably break as the team refines their design. Let's assume they're really wasteful, and each team member breaks 6-7 eggs, or about $1 in eggs a piece. $1 for a very valuable lessing in practical engineering seems like a great investment to me!

Sure, you could donate eggs to a homeless shelter, or dehydrate them and include them in food aid to Burma and China. Trust me - people who run homeless shelters and food aid programs know exactly how cost-effective eggs are when it comes to feeding the poor and starving. And they most likely prefer to get that $1 in cash instead, which gives them a lot more flexibility.

So now your question becomes:

Is it more important to spend $1 to teach an engineering student a valuable lesson, or to donate that $1 to feed starving people... In the end, a $1 egg experiment is going to be FAR more cost-effective than a similar experiment using and extra $10 in cardboard, elastic, rubber balloons and hot glue instead.

After all, it's not as if eggs are a limited resource. Eggs are a great renewable resource - that's why they're so cheap in the first place...
uguy in reply to PatrikMay 28, 2008. 8:09 PM
You miss the point completely. It's not about the money, it's about the wasted food. Even if they donated an egg for every one wasted, it would still be a waste of an edible nutritious egg. You can't tell me there are no other ways to learn about "how not to break an egg".
Patrik in reply to uguyMay 28, 2008. 8:42 PM
Except that it's not wasted.

An egg is multi-functional: yes it's food, but it is also a valuable engineering lesson. Eggs are also used to manufacture flu vaccines, for example - would you call that "wasted"? Biology students do all sorts of interesting experiments using fertilized chicken eggs - great for observing embryo development, for example. Why would it be more acceptable for a biology student to "waste an egg" in a valuable learning experience, than an engineering student?

There are so many other types of waste more deserving of your attention. Go ahead, break an egg or two to learn something useful. Then go dumpster diving for dinner...
instructiondude in reply to PatrikJan 24, 2009. 9:47 AM
I agree with uguy first of all the egg is wasted because after you use the egg i dont think anyone will go and eat it. they will just throw it away even if it did not break. i bet you wont eat it either after you used the egg in your experiment.
ElChick in reply to instructiondudeMar 6, 2009. 1:14 PM
I'm sorry, but I have to pipe up and add my 2 cents and agree with Patrik.

The point is that even though the egg is not being eaten, it is not being wasted, because it is being used to educate. Instead of becoming "stomach-food," it is literally becoming "brain-food!" :)
JennyROX94 says: Feb 16, 2009. 1:38 PM
if you put an egg inside of a sponge and wrap it around in cottonballs and then surround by mesh bath scrubber material it actually works
bob the builder #1 says: Jul 21, 2008. 9:57 AM
I had to use straws and masking tape(yes there was a limited amount)And I lost to some kid using an easter egg filled with water.
liny says: May 28, 2008. 7:16 PM
my eggdrop competition was stupid. in my school, when i did that competition in 6th grade in a camp, i just put my egg inside a tissue roll, that tissue roll inside and nother big tissue roll, and a big cereal case full of tissue. I put everything together to make a monitor sized pillow. The egg didn´t break. : D
CameronSS says: May 25, 2008. 7:08 AM
Nice! The last egg drop competition I was in allowed the use of helium. I got ninth with a super-light structure and a parachute, and places one through eight were taken by kids who did no engineering at all, just attached helium balloons to ziplock bags until they showed under ten grams on the scales, including the egg. Yeah, I'm bitter.
bhunter736 in reply to CameronSSMay 28, 2008. 8:11 AM
Dont be bitter. Be proud. You have the mental power to work with a great deal more situations. And you also recognize that there is more than one way to do things. The other competitors just took the easy way. Now if it was not supposed to be a competition for the best way to handle the situation then you could be bitter. You didnt use a limited resource wastefully. Your design would hold up over time, the helium would escape the balloons in short order. Imagine if the goal was to air drop the eggs in another country and there was 2 or 3 days in transit and handling before the drop. The balloons would have lost their helium before the drop! Your design would be ready to go. Yours is also re-usable it sounds like. Keep up the good work. : ) PS - You gained a lot from the competition, the balloonists did not. They do not know any more than my 4 year old son about floating stuff. He loves balloons. You just need a competition suited to your higher abilities.
CameronSS in reply to bhunter736May 28, 2008. 10:04 AM
Actually, I overheard a teacher talking to a judge, saying that they were disappointed that the rules had allowed their students to do so little work and still do well. That was the last year I was eligible, so I haven't checked, but I think they were planning to take helium out of the "permitted" list, as it killed the competition.
CameronSS in reply to bhunter736May 28, 2008. 9:03 AM
:-D I was kind of joking, actually. I'm used to that kind of thing. I have morals, and even when I have an easy chance, I refuse to cheat or copy in class. I then see someone sitting next to me passing their quiz to the person behind them. It's obnoxious, but it's life, and I can't do anything about it. Mostly, the annoying bit was that the first prize was a TI-84. Ninth prize was a few pencils and a keychain.
Rock Soldier in reply to CameronSSJan 23, 2009. 5:24 AM
What's a Tl-84?
CameronSS in reply to Rock SoldierJan 23, 2009. 6:54 AM
bhunter736 in reply to CameronSSMay 28, 2008. 9:49 AM
Oh well. A TI-84 would have been nice. At least pencils can do the same thing with the right operator. ; ) Just not as much fun.
Bongmaster in reply to CameronSSMay 25, 2008. 8:29 AM
the fiends :(
bhunter736 says: May 28, 2008. 8:13 AM
Excellent build! : )
Mr. Squiggles says: May 25, 2008. 5:57 PM
I find that air-filled balloons can keep one side facing up and with the right wind let the egg drift down
theRIAA says: May 25, 2008. 12:08 PM
the best egg drop contraption iv'e ever made was a small, padded on the inside cardboard box, just big enough for the egg, attached with rubber bands to a 11" cube frame made with cardboard folded in triangular tubes, 1/2 assedly ducktaped together. The egg would survive well above the boxes terminal velocity. Even me and my teammate threw it at the floor and brick walls at our school as hard as we could, it wouldn't break.
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!