Topic: School project -model rocket propulsion (Read 8586 times)

Nordlys · « **on:** June 13, 2015, 11:25:09 am »

Good morning to all the clever ones
As part of Grandads homework I have to design and make fly a 30cm model rocket as far as possible (not height)
for my grandsons school project.
Can anyone come up with a few suggestions that might help me to get going on this please?
Doesn't have to be fizzy drinks or compressed air systems.

Nordlys.........

Shipmate60 · « **Reply #1 on:** June 13, 2015, 11:46:51 am »

Jetex Motor, if unsure just google it.

Bob

Arrow5 · « **Reply #2 on:** June 13, 2015, 11:53:46 am »

Limited motor run with jetex. Try FAI rocket launch glider class, big in Eastern Europe, World Championships etc etc . There is also Pure rocket class but that IS mainly for height.

tigertiger · « **Reply #3 on:** June 13, 2015, 01:17:11 pm »

I would check with the school. Seriously.
If you are not just going for height, but distance, then it is a projectile. I am almost certain that there will be legal (police) issues if the rocket were to fly in public areas (beyond the school fence), as well as H&S issues to deal with.
The school may be expecting a non-combustion propulsion system. Which would rule out Jetex.
They may also be wanting the rocket to go as far as possible, but not expect it to go beyond the school playing fields.

Nordlys · « **Reply #4 on:** June 13, 2015, 01:33:46 pm »

These replies have concentrated on fuelled propulsion- I am looking for something homemade,
simple, safe and certainly well within school grounds length of flight.I had in mind a spring launching
method and I'm sure there are a few engineers on Mayhem that might have an idea?
N

Plastic - RIP · « **Reply #5 on:** June 13, 2015, 01:35:18 pm »

Elastic bungee launch using model aircraft rubber motor elastic - like a big slingshot!

hmsantrim · « **Reply #6 on:** June 13, 2015, 01:40:13 pm »

plastic just beat me to it. somthing like this idea.
frank
http://www.rubber-power.com/how-to-make-a-propeller.htm

Plastic - RIP · « **Reply #7 on:** June 13, 2015, 01:45:48 pm »

I was thinking the stuff that's about 6mm x 1mm and comes on a roll - get a bit of 2x2 wood about 6' long and make a launch tower - loop the elastic a few times and have a launch hook (from a model glider) fitted to the side of the rocket - with the elastic fitted to the top of the launch tower, stretch down to the ground and attach to a loop of cord.

Cut cord to launch!

you can make the launcher as strong as you or your rocket design can withstand - expect to reach several hundred feet straight up!

(your rocket will be structurally closer to a crossbow bolt).

hmsantrim · « **Reply #8 on:** June 13, 2015, 01:50:51 pm »

Hi grandad.
some homework for you to swat up on..

frank
https://www.google.co.uk/search?sourceid=navclient&aq=&oq=home+made+r&ie=UTF-8&rlz=1T4GUEA_enGB581GB581&q=homemade+rocket&gs_l=hp..1.0j0i10l4.0.0.0.1266877...........0.hnSWdZRpOXc#q=homemade+rocket+for+kids

https://www.google.co.uk/search?sourceid=navclient&aq=&oq=home+made+r&ie=UTF-8&rlz=1T4GUEA_enGB581GB581&q=homemade+rocket&gs_l=hp..1.0j0i10l4.0.0.0.1266877...........0.hnSWdZRpOXc#q=homemade+rocket+fuel

Martin (Admin) · « **Reply #9 on:** June 13, 2015, 02:00:57 pm »

Water bottle rocket?

Are Estes still around?!

inertia · « **Reply #10 on:** June 13, 2015, 03:00:21 pm »

Are Estes still around?!

Very much so, it seems - along with a lot of other rocketry stuff http://www.modelrockets.co.uk/shop/
The project did say "design" though. I wonder how far commercially-available items could be included in that. I think TT is right in that it would be a good idea to find out just what the school are expecting. It's a bit vague as it stands.
DM

Nordlys · « **Reply #11 on:** June 13, 2015, 03:36:34 pm »

Ok, the school brief says :- No ready made balloon pumps, no electricity,water or chemicals in any element of the
design.
Use only everyday mat'ls to manufacture the rocket and for the launch use stored energy, such as stretched elastic
as an example.
I have in mind a single compressed spring - sounds a bit tame?
It may well be! But its not built yet, it may fly , it may flop.
But I'm still very open for other ideas guys?
Thanks...
Nord.....

malcolmfrary · « **Reply #12 on:** June 13, 2015, 04:27:33 pm »

Perhaps someone should get the school to invest in a dictionary or at least look up technical terns on wiki - a device launched by an elastic band is not a rocket - a projectile, yes.
https://en.wikipedia.org/wiki/Rocket
Are they looking for a flying device, something propelled by a self contained energy store, or just something that can be persuaded to travel? A hand propelled tennis ball will go a fair way, probably further if swatted with a tennis bat.

Arrow5 · « **Reply #13 on:** June 13, 2015, 05:49:29 pm »

Rocket ? Not being pedantic but a rocket is just that. What is this school teaching ?

tigertiger · « **Reply #14 on:** June 13, 2015, 06:00:44 pm »

Stored energy. Hmm? Does that include trebuchet?
It also says no 'ready made' balloon pumps. That implies that if you design and build a pump you can use it. A girt big pump making compressed air would be stored energy, and a rocket.

Maybe a big bellows feeding into a bottle with fins. Maybe a small bottle. If you have a push friction fit, and then maybe jump on the bellows, you won't even need a valve.

Netleyned · « **Reply #15 on:** June 13, 2015, 06:27:11 pm »

Quote from: arrow5 on June 13, 2015, 05:49:29 pm

Rocket ? Not being pedantic but a rocket is just that. What is this school teaching ?

Rocket Science ??

Ned

Arrow5 · « **Reply #16 on:** June 13, 2015, 08:53:28 pm »

Quote from: Netleyned on June 13, 2015, 06:27:11 pm

Rocket Science ??

Ned

You think ?

tonyH · « **Reply #17 on:** June 13, 2015, 10:21:07 pm »

The elastic/spring system is only the same as a basic bow and arrow. All the thrust is at the start which means that the 'rocket' has to be fairly strong to withstand the initial 'urge'.
If you look up the pulley system on what is called a 'compound' bow, the urge is progressive and the 'rocket' would be accelerated and could be made lighter.

Could be a more efficient option but that's assuming that they do mean a projectile as Malcolm mentioned?

Good Luck

grendel · « **Reply #18 on:** June 14, 2015, 06:22:51 pm »

what about launching using a 'throwing stick'?

tonyH · « **Reply #19 on:** June 14, 2015, 10:26:27 pm »

Isn't that a Woomera? If so there's a precedent already set

Jerry C · « **Reply #20 on:** June 14, 2015, 10:33:55 pm »

Google Dutch Arrows.
Jerry.

Arrow5 · « **Reply #21 on:** June 15, 2015, 11:27:30 am »

Ah did an` just got a lot aboot Holland an` aw that stuff aboot tulips an` clogs an` winmills.

Perkasaman2 · « **Reply #22 on:** June 15, 2015, 01:35:27 pm »

Some of these kid's homework projects are a nightmare for parents.

hazegry · « **Reply #23 on:** January 16, 2016, 03:54:29 am »

co2 cylinder powered slot car. use the same materials they use for the gravity cars like the boyscouts make put eyelets under tha car and run a string from one end of the parkinglot or flat surface to the other. we built a box with a nail on a spring that had slots for the wheels so there was just enough resistance for the nail to punch a hole in the cylinder. the string keeps it from becoming a hazard make sure its tight and at the same level as the eyelets so the string doesn't act like a brake. Even if you used an elastic band to launch it the string keeps bad things from happening

Umi_Ryuzuki · « **Reply #24 on:** January 16, 2016, 06:23:01 am »

Booster glider.... Since it isn't a true rocket, a couple of swept
wings might keep it gliding for distance.

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Author Topic: School project -model rocket propulsion (Read 8586 times)

inertia