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Model Rocket Safety Code
NASA - Beginners Guide to Rockets
How do I get started?
Launch Site Minimum Dimensions
What is clustering?
What is staging?
Engines/Motors Wadding
Flight Profile/Sequence
Excel Rocket Calculations 
- burn time calculator
-speed conversions
- altitude conversions
- how to calculate altitude
- parchute sizing
- Steamer Sizing
Body Tubes
Electronics
- Altimeters
-Beepers
Streamers

Model Rocket Safety Code
  1. Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket.
  2. Motors. I will use only certified, commercially-made model rocket motors, and will not tamper with these motors or use them for any purposes except those recommended by the manufacturer.

  3. Ignition System. I will launch my rockets with an electrical launch system and electrical motor igniters. My launch system will have a safety interlock in series with the launch switch, and will use a launch switch that returns to the "off" position when released.

  4. Misfires. If my rocket does not launch when I press the button of my electrical launch system, I will remove the launcher's safety interlock or disconnect its battery, and will wait 60 seconds after the last launch attempt before allowing anyone to approach the rocket.

  5. Launch Safety. I will use a countdown before launch, and will ensure that everyone is paying attention and is a safe distance of at least 15 feet away when I launch rockets with D motors or smaller, and 30 feet when I launch larger rockets. If I am uncertain about the safety or stability of an untested rocket, I will check the stability before flight and will fly it only after warning spectators and clearing them away to a safe distance.

  6. Launcher. I will launch my rocket from a launch rod, tower, or rail that is pointed to within 30 degrees of the vertical to ensure that the rocket flies nearly straight up, and I will use a blast deflector to prevent the motor's exhaust from hitting the ground. To prevent accidental eye injury, I will place launchers so that the end of the launch rod is above eye level or will cap the end of the rod when it is not in use.

  7. Size. My model rocket will not weigh more than 1,500 grams (53 ounces) at liftoff and will not contain more than 125 grams (4.4 ounces) of propellant or 320 N-sec (71.9 pound-seconds) of total impulse. If my model rocket weighs more than one pound (453 grams) at liftoff or has more than four ounces (113 grams) of propellant, I will check and comply with Federal Aviation Administration regulations before flying.

  8. Flight Safety. I will not launch my rocket at targets, into clouds, or near airplanes, and will not put any flammable or explosive payload in my rocket.

  9. Launch Site. I will launch my rocket outdoors, in an open area at least as large as recommended and in safe weather conditions with wind speeds no greater than 20 miles per hour. I will ensure that there is no dry grass close to the launch pad, and that the launch site does not present risk of grass fires.

  10. Recovery System. I will use a recovery system such as a streamer or parachute in my rocket so that it returns safely and undamaged and can be flown again, and I will use only flame-resistant or fireproof recovery system wadding in my rocket.

  11. Recovery Safety. I will not attempt to recover my rocket from power lines, tall trees, or other dangerous places.

Minimum Launch Site Dimensions

Installed total impulse
(newton-seconds)
 Equivalent
motor type		 Minimum Site Dimensions
(m / feet)
0-1.25
1/4A & 1/2A
15 / 50
1.26-2.50
A
30 / 100
2.51-5.00
B
60 / 200
5.01-10.00
C
120 / 400
10.01-20.00
D
150 / 500
20.01-40.00
E
300 / 1000
40.01-80.00
F
300 / 1000
80.01-160.00
G
300 / 1000
160.01-320.00
2G's
450 / 1500

SAFE DISTANCE TABLE
Total Impulse All Engines (Newton-Seconds) Equivalent Motor Type Minimum Distance From Rocket With Single Motor (ft.) Minimum Distance From Rocket With Multiple Motors (ft.)
160.01 -- 320.00 H 100 200
320.01 -- 640.00 I 100 200
640.01 -- 1,280.00 J 100 200
1,280.01 -- 2,560.00 K 200 300
2,560.01 -- 5,120.00 L 300 500
5,120.01 -- 10,240.00 M 500 1,000
10,240.01 -- 20,480.00 N 1,000 1,500
20,480.01 -- 40,960.00 O 1,500 2,000
 
How do I get started in rocketry?
 
In my opinion, go out and buy an Estes starter set. My first one was the Alpha III (Estes Product #1406). It came with the rocket and launch pad. You will need to buy glue, finishing supplies, wadding and the engines. The rocket is easy to build and flies to 1100 feet! See the links section for places to purchase rocket kits.
Here are the specs:
Length: 12.3 in.; Dia.: 0.98 in.; Wt.: 1.2 oz.; Parachute Recovery; One piece plastic molded Fins; Max. Altitude: 1100 ft. Recommended motors: A8-3, A8-5, B4-4, B6-4, B6-6, C6-5, C6-7
 
I also recommend you join a club. The members are always willing to teach you something new and show you how they built their rockets. You can find links to some of these clubs in the links section. Don't forget to check out the club calendars. They usually contain their lauch schedules.
 
Other recommendations:
 
Rocksim from Apogee Components - This is a software package that allows you to model and fly your rocket before you build it. This is great when you decide to start building your own rockets from scratch. My first scratch rocket was built using the Estes Designer kit (Estes Product #1463) which I bought on Ebay. I designed it on Rocksim first, launched it, watched it follow the Rocksim flight profile and make a graceful landing into the middle of a lake.
Estes Rocket Builder Marking Guide - This little gadget helps you align your fins correctly.
Get the book "Model Rocket Design and Construction " by Timothy S. Van Milligan. This book talks about creating unique and exciting model rockets that work.
 
Other fun sets:
Estes Mean Machine
SPECS: Length: 78.8 in.; Dia.: 1.64 in.; Wt.: 5.8 oz.; Parachute Recovery; Die cut balsa Fins; Max. Altitude: 600 ft. Recommended motors: D12-5
Estes Snapshot
Length: 18 in.; Dia.: 1.35 in.; Wt.: 3.0 oz.; Parachute Recovery; Plastic molded Fins; Max. Altitude: 500 ft. Recommended motors: C6-5 only.
Estes Max Trax
Length: 17 in.; Dia.: 1.35 in.; Streamer and Parachute Recovery; Plastic molded Fins. Recommended motors: B4-2, B6-2, C6-3, C6-5
Estes Cosmic Cobra
Length: 19.5 in.; Dia.: 1.35 in.; Wt.: 3.1 oz.; Helicopter and Parachute Recovery; Two piece plastic molded Fins; Max. Altitude: 530 ft. Recommended motors: B4-2, B6-2, B6-4, C6-3, C6-5
 
Tips and Tricks
Sometimes on a light weight model it makes sense to use a streamer instead of a parachute to avoid the risk of the rocket drifting a long distance before landing. Also cutting a few slots in the parachute can make the model come down quicker.
 
Here are some screenshots of Rocksim
 
 
 
What is staging?
 
Using multiple engines stacked on each other and then fireing in succession is staging. A good beginers rocket with staging is the Estes Express (Length 28.38" Dia. 1.33" Wt.: 2.7 oz  Engines: Single Stage; C11-5, D12-5. Two Stage Booster: D12-0. 2nd Stage: C11-5, C11-7, D12-7).
 

 
What is clustering?
 
Simultaneous ignition of multiple rocket engines to attain higher thrust liftoff. It's a good idea to use the same ignitors in all of the motors. You should also check that they are all in good shape. 
Total thrust and impulse = sum of thrust and implulse of the individual engines.
This came from my Flis Kits Tres manual.
 
 
Engines/Motors
 
How does a model rocket engine work?
1. The engine is ignited, produces thrust and boosts into the sky.
2. After the propellent has burned up a delay is activated and then tracking smoke may be emitted.
3. After the delay a ejection charge is fired deploying the recovery system.
 
 
First, let's start with the designation codes on the engine. The first letter is the power code (Total Impulse/Total Power).  As an example, a "B" engine has twice the power of an "A" engine (see figure below). The second number is the average thrust level. For instance in a B6-4 the engine produces 6 newtons of thrust over it's burn time (a newton is equivalent to 0.225 pounds of thrust). The last number is the delay time in seconds before the ejection charge will fire after the burn is complete (also called burn-out). So on a B6-4 there will be a 4 second delay after burn-out before the ejection charge fires. With these designations you can also calculate the approximate burn time. Using the table below, divide the maximum power by the average thrust.
 
Here is an example using a B6-4.  5 (maximum power - see table below )  / 6 (average thrust level)  = .83 (approximate burn time)
 
Code Newton Seconds
1/2A 0.625 1.25
A 1.26 2.50
B 2.51 5.00
C 5.01 10.00
D 10.01 20.00
E 20.01 40.00
F 40.01 80.00
G 80.01 160.00
H 160.01 320.00
I 320.01 640.00
J 640.01 1280.00
K 1280.01 2560.00
L 2560.01 5120.00
M 5120.01 10240.00
N 10240.01 20480.00
O 20480.01 40960.00

So, why do you care? Well if you want your rocket to survive the launch you will need to know these numbers. You don't want to select a thrust level that's will rip your rocket apart on launch or does not have enough thrust to lift the weight of your rocket. You also don't want a delay that fires your ejection charge when the rocket is still at a high coast speed or already on the ground.
 
Using Rocksim is a great way to determine if the engine you have selected is appropriate for your rocket.
 
If you see a letter at the end of Aerotech motors they indicate the propellant formulation.
 
W - White Lightning
T - Blue Thunder
J - Black Jack
FJ - Black Max
R - Redline
 
Now let's talk about the color coding on rockets. This is pretty simple.
 
Green - Single stage.
Purple and Blue - Top stage of Multi-staged rocket.
Red - Booster and Intermediate staged rocket.
 
Motors also come in standard diameters.
29mm      Used for H thru I power motors. (G motors are also normally 29mm)
38mm      This is the most common high power motor size, used for H thru J power motors.
54mm      Motors for 54's usually begin at J and go to L power.
75mm      (or 76mm) Also called 3-inch motors. They are usually K thru M in power.
98mm      Also called 4-inch. These are for L thru N power motors.
152mm   This is six inches.
 
In reloadable motors the tubes of propellant are called grains.
 
Types of propellants. 
The two main types of propellants are black powder and composite.
 
What is the difference between Model Rocketry, Mid Power Rocketry and High Power Rocketry? Well it's the type of motor used.
Model Rocketry - A,B,C,D
Mid Power Rocketry - E,F,G
High Power Rocketry (HPR) H,I,J,K,L,M,N,O
You must be level 1 certified to fly H and I motors, level 2 certified to fly J, K and L motors and level 3 certified to fly all others.
 
Reloadable Motor Systems
 
With reloadable motor systems you can enjoy flying high powered rockets at a greatly reduced cost.  THe first thing you will need is the motor. This usualy consists of a motor casing, and a forward and aft enclosure. A case will usually have a number like 29/240. This means the motor diameter is 29 millimeters and the maximum total impluse is 240 N-sec. Next you will have to puchase the reload kit. You must make sure you purchase a reload kit that fits your casing. Most rocketers will have multiple sized casings. You can even get reload kits for engines as small as a "D". This is a good place to start and learn how to assemble these motors.  Be sure to pay attention to were the spacers and 0 rings go. I destroyed my level 1 rocket when I put the O rings in backwards.
 
Do not fly a rocket engine combination whose lift-off weight exceeds the enigines recommended lift-off weight.
 
Wadding
 
Wadding is a fire resistant material that is placed between the ejection charge and parachute.  The material needs to be biodegradeable.
 
The wadding for low power rockets is pretty straight forward. You buy the sheets from Estes or Quest. I have to admit it took me a bit of time to figure out what was used for high power rocketry. After doing some research online I found out that the wadding is cellulose insulation available at any large home building store. I bought a huge bail at Menards for $4.74
 
Body Tubes
 
 
Name Inside Outside
Dia. Dia.
     
BT-5 0.515" 0.541"
BT-20 0.710" 0.736"
BT-30 0.725" 0.765"
BT-50 0.950" 0.976"
BT-55 1.283" 1.325"
BT-58 1.498" 1.540"
BT-60 1.595" 1.637"
BT-70 2.175" 2.217"
BT-80 2.560" 2.600"
 
These do vary from manufacturer to manufacturer
 

Electronics

I've purchased my first altimiter and it's the PerfectFlite A15K which I purchased from Apogee Components. As you can see from the picture it is extremely small and has data transfer capabilities. The data transfer kit must be purchased seperately.

Perfect Flight Alt 15K Data Capture

A sample of the data capture program included with the altimeter. This was an acutal flight.

Beeper

If you need a load low cost beeper. Go to Radio Shack and purchase one of their Mini Personal Alarms. The part number is 49-428.  These have a pin that when it is pulled out produces and ear ppiercing 140db alarm. Hook one end to you nose cone and tape the other end to your shock cord. When the nose ejects it will pull the pin and turn on your beeper.

  Streamers

Use streamers on any small rockets with a mass less then about 1.05oz. The area of the streamer depends on the weight of the rocket. In general the streamer should be at least 10 times its width. Checkout my Excel spreadsheet of calculations for more precise sizing.     Excel Rocket Calculations