Questions from new rocketeer

[RICHARD COLARCO]

My granddaughters have shown an interest in rockets. We are lucky to live near NASA/Goddard Space Flight Center, who host a rocket outing every month. I have purchased an Estes starter kit, which looks pretty straightforward for a beginner. I would like to launch from my front yard, which is about an acre and pretty square. Of course I would like to recover the rocket, so I want to start small. The kit comes with the following motors:

A8-3
B6-4
C6-5

The rocket, sans motor, weighs 1.25 ounces. Running the rocket equation leads me to believe the A8-3 will raise the rocket to about 437 feet, the B6-4 to 1700 feet, and the C6-5 to almost 6000 feet! (ignoring drag) Am I missing something? Are these numbers realistic?

Of course I would like to recover the rocket, which does not appear to be a good expectation if I use any but the smallest motor.

Can I get a smaller motor for a good first proof of concept flight? Which motor should I get? What is the lowest impulse motor I can use?

Thanks for the help.

 

[Jim Hinton]

Het Richard;

Given the size of your field, you should be fine with A's and B's given a calm to light breezes day. You want to make your initial flights with little to no wind until you get an idea of what kind of drift to expect etc. I would guess that the altitude estimation for the 'A' motor is about right. With the B it should go to about 1000', the C will go to about 2000'. You double in total power with every letter of the alphabet. A 'B' has twice the power of an 'A' etc. I would make my initial flight on an A 8-3, with little to no breeze, check the sky for aircraft in your vicinity and let them clear prior to launch. B's will make for a more interesting flight, a C will fly it out of sight (literally). Have fun and be safe!

Jim

 

[jsdemar]

There are rocket flight simulators to give a more realistic altitude estimate.
https://www.thrustcurve.org/simulation.shtml
https://www.thrustcurve.org/simulators.shtml

Here's a free online simulator: https://www.rocket-simulator.com

 

[RICHARD COLARCO]

Het Richard;

Given the size of your field, you should be fine with A's and B's given a calm to light breezes day. You want to make your initial flights with little to no wind until you get an idea of what kind of drift to expect etc. I would guess that the altitude estimation for the 'A' motor is about right. With the B it should go to about 1000', the C will go to about 2000'. You double in total power with every letter of the alphabet. A 'B' has twice the power of an 'A' etc. I would make my initial flight on an A 8-3, with little to no breeze, check the sky for aircraft in your vicinity and let them clear prior to launch. B's will make for a more interesting flight, a C will fly it out of sight (literally). Have fun and be safe!

Jim

Jim,

Thanks very much. I will start with the A motor and measure the altitude with the protractor thingy, then go from there.

- Rich

 

[RICHARD COLARCO]

There are rocket flight simulators to give a more realistic altitude estimate.
https://www.thrustcurve.org/simulation.shtml
https://www.thrustcurve.org/simulators.shtml

Here's a free online simulator: https://www.rocket-simulator.com

Thank you. Those are very useful.

 

[smugglervt]

My granddaughters have shown an interest in rockets. We are lucky to live near NASA/Goddard Space Flight Center, who host a rocket outing every month. I have purchased an Estes starter kit, which looks pretty straightforward for a beginner. I would like to launch from my front yard, which is about an acre and pretty square. Of course I would like to recover the rocket, so I want to start small. The kit comes with the following motors:

A8-3
B6-4
C6-5

The rocket, sans motor, weighs 1.25 ounces. Running the rocket equation leads me to believe the A8-3 will raise the rocket to about 437 feet, the B6-4 to 1700 feet, and the C6-5 to almost 6000 feet! (ignoring drag) Am I missing something? Are these numbers realistic?

Of course I would like to recover the rocket, which does not appear to be a good expectation if I use any but the smallest motor.

Can I get a smaller motor for a good first proof of concept flight? Which motor should I get? What is the lowest impulse motor I can use?

Thanks for the help.

A little tip...cut out the logo on the Estes parachutes to create a spill hole. The rocket will drift less and still come down slow enough to prevent a hard landing.

 

[RICHARD COLARCO]

A little tip...cut out the logo on the Estes parachutes to create a spill hole. The rocket will drift less and still come down slow enough to prevent a hard landing.

Excellent advice, thank you. This why it is good to ask people with experience!

 

[Rex R]

I feel that I would be remiss if I didn't mention that most model rockets come with a list of recommended engines(including suggestions for first flight).
Rex

 

[RICHARD COLARCO]

Rex,

Thanks. My Estes kit makes no reference to the engines, except for launch site dimensions. Even these are poorly explained. The Estes catalog has a lot more information.

- Rich

 

[Rex R]

so which kit/set did you get?

 

[GlenP]

only set I know of that includes engines:
https://www.estesrockets.com/rockets/starter-sets/005302-rocket-science-starter-set

 

[OverTheTop]

Welcome to the forum Richard. If you are working towards bigger motors I suggest you buy another rocket kit . You can fly that when you lose the other one in a tree or on a roof. Been there, done that. If you look at kits with bigger diameter they don't go as high with the bigger motors, and look more impressive.

To check if your rocket is stable with the larger motors, Google "swing test rocket". Don't forget "rocket" in the search term or you might get some weird stuff. The simulators will check stability also, but for small rockets a swing test is easy. Kits should be stable with all recommended motors but it doesn't hurt to check.

Enjoy .

 

[Rex R]

assuming that is the set, then about 200' on an A8-3 (need about 100 foot square for a 10mph breeze). on a C6 you probably will not see it again .

 

[K'Tesh]

Welcome!

If you want to spend the time, you can always download OpenRocket (OR) and sim up what you've got. RocketReviews frequently has sims (.rkt files) of various kits. That said, RR doesn't have any quality checking, and the info on it can be downright wrong sometimes (Latest example I found someone gave the kit number for the Estes Menace (missile version) as 2041... and not 2173). So, caveat emptor.

 

[Matt_The_RocketMan]

I can personally tell you that an Alpha rocket is best to start off with its easy to build, it teaches you almost everything you need to know about simplistic model rocketry. I would personally use A8-3 engines due to their overall performance. Also 1 acre is plenty enough to shoot L.P.R.in just don't shoot near trees they kill rockets and kites. If you have , more questions ask me Im personally a Model Rocket Commander and we shoot for a living / training almost 3 times a week ... but don't be afraid to ask the more experienced guys also on this topic

 

[K'Tesh]

Oh, the old Alpha with the old nosecone... That looks so much better than the current version of the nosecone.

Though I must say... I like the new paint scheme seen on the facecard with the white nosecone and the blue fin.

To the OP... I have a sim of the Alpha in my OpenRocket files thread.

 

[Matt_The_RocketMan]

Oh, the old Alpha with the old nosecone... That looks so much better than the current version of the nosecone.

Though I must say... I like the new paint scheme seen on the facecard with the white nosecone and the blue fin.

To the OP... I have a sim of the Alpha in my OpenRocket files thread.

This rocket is so generic like its cousin Alpha III its also one of those super easy build and is reliable to thousands of shots.