Cub Scout Rocketry

[Eliza]

Very basic questions here:

I see the rockets take various engines -- how do you choose which engine to get?

And, any launch pad recommendations?

[rdclements]

Eliza,

 

The letter codes on the engines indicate the 'impulse' range of the engine. Impulse is calculated as how much force for how much time. As the engine letters go up, the total impulse roughly doubles.

Look at a common engine, like an A8-3.

The A class indicates a total impulse between 1.25 and 2.5 Newton-seconds.

The 8 indicates that the engine produces 8 Newtons of thrust (average).

The 3 indicates that the delay time from the end of the thrust phase to the ejectino charge is 3 seconds.

 

For the average kit rocket, overall height for a flight will roughly double for each succeeding class of engines. This means you can fly the same rocket in a small field on an A engine and then fly it in a larger field on a B or C.

 

The basic launch gear that you find in a hobby store, like the Estes controller and tripod pad, works fine. It is a lot more fun to build your own. I still use some stuff that I built in 1974.(This message has been edited by rdclements)

[Eagle92]

The rocket kits will suggest what size engines to use. if memory serves, 1/2A and A are the same diameter, B and C engines are teh same diameter EXCEPT C11-6, which is the size of D engines.

 

I found a deal on C11-6 engines, 30 engines for about $20 with shipping, only to find they do not fit the C size engine mounts one I got them for.

 

SOOOOOOOOO I had to buy a bigger rocket for my engines (This message has been edited by eagle92)

[5yearscouter]

Oh and when our pack was planning our first rocket launch day

we looked for rockets, and realized that the ones on scoutstuff.org are estes model rockets that those NAMES of rockets are being discontinued, but the shape/design/size of the rocket was still around most likely in a different color.

so we bought a sample rocket at Michael's locally with their coupon in the paper for 40% off one item, put it together checking out how long, how detailed, what supplies, and how to make it so even the youngest scouts could do PART of the work. then put it together, bought a small pack of rocket engines that would fit used a launch controller and launch pad we already had, went to the location we wanted to use and checked out how far it would probably go when we launched it so we had some ideas of what we were working with.

 

we also cancelled launch day 4 times due to excessive wind for the park area we were using.

 

 

[SeattlePioneer]

>

 

 

Bummer.

[Eliza]

rdclements

Thank you for explaining the engine differences. I had noticed that the Wizard, for example, took various engines. Now I see why. We are in the suburbs, without big, empty fields, so I am thinking that the smaller engines will do for us.

[ScoutNut]

You can not hold a rocket launch in your back yard. You will be losing rockets in power lines, trees, and neighbors back yards. Not fun.

 

You need to find a large open field somewhere.

 

A ball field might work if you put your launch pads at the far end with the wind behind you. Even then, we used a ball field once and still lost a number of rockets to power lines.

 

Check out your local Park District, or Forest Preserve. Many picnic areas have large open spaces.

 

Even if you have to travel a bit to a good spot, it is more fun for the boys if they can retrieve, and re-launch their rocket a number of times.

 

 

 

[clemlaw]

Let me reiterate SP's original question:

 

>>>>What are likely ways of acquiring enough experience with those to use them in a Cub Scout outing?

[Eagle92]

What I did was buy a starter kit, specifically the Star Wars Naboo Fighter Kit, that included the following:

 

NABOO Fighter model rocket

Wadding

parachute

launch pad

R2D2 launcher

 

All I had to buy extra was batteries and engines. Read all the safety instruction in hte kit, helped boys put it together, went to the field, prayed it would work, and WHAM it launched. Total time to prep, launch, and recover was bout 2 hours of work, and one night of glue drying.

 

With the great weather tomorrow, I'm thinking launching some rockets before PWD.

 

And yes if you bought yourself a Star Wars Naboo Fighter rocket kit, you might be a Star Wars fanatic

[clemlaw]

Ah, read the instructions. Why didn't I think of that!

[5yearscouter]

We had issues with the county parks having a no Estes rocket policy.

I guess someone launched some rockets and made a mess and then someone thought they'd also catch fire to brush--although that is pretty unlikely.

 

to get the experience, go out and buy a sample like I said from Michaels, and read all the directions 3 times then build and launch. launch it several times til you run out of engines. Ask if anyone in your pack has any experience with rockets, you'll probably find someone who knows how to do it. there are some more info at Estes rockets online that may help you feel more prepared. and read the safety rules with the boys and parents before launching.

 

[5yearscouter]

We also have a star wars rocket.

unfortunately the little star wars ship doesn't fit on the rocket anymore. it hit too hard one time with a parachute malfunction.

[Eliza]

SeattlePioneer

I almost forgot to thank you for your original post -- I told the teacher who runs the model rocket club at my son's school about the prices and he was thrilled to get the info.

 

Thinking about your question about experience -- would any of the elementary schools near you have model rocket clubs? Someone who runs one would have experience with the Cub-level age group and also might be a help with any local regulations, good places to launch, etc.

 

Also, another slightly related thought -- there is a wonderful, based-on-a-true-story movie called October Sky, about a high school boy, in the late 1950's who built model rockets (and went on to become a NASA engineer).

[rdclements]

Yes, a simple kit like the Wizard uses the 18mm diameter engines. The larger ones are 24mm.

It does help to have someone with experience, so grabbing a starter kit and learning by doing is a good suggestion.

As 5year mentioned, brush fires are are possible, so have some water buckets standing by.

 

There are some good resources on the Estes web page for teachers. Here's the link:

http://www2.estesrockets.com/cgi-bin/WEDU100P.pgm

 

Here's a link to their recommendations for the size of the field needed for each engine size:

http://www2.estesrockets.com/pdf/launchsite.pdf

 

I built a 4 position launch pad. If you have multiple single launch pads you can get the same setup.

Use some stakes and flagging to mark out the launch safety area.

Only scouts loading their own rocket along with their helpers are allowed out to the pad.

Once a set of rockets is loaded and wires connected, everybody gets behind the safety line.

Safety check, circuit check, launch warning, clear range, countdown, launch - either singly or in a group.

If you plan ahead, model rocketry can lead to many scientific learning activities. Each age group can do their own thing to prepare and enjoy the launch event.

[61rover]

We found good pricing at: www.acsupplyco.com. The Generic bulk pack is very affordable ($5/rocket) and is designed so the boys can decorate how they wish. Engine bulk packs are a good deal too.