If You Fly Often, Aerotech Reloadable Rocket
Motors Will Save You Money!

The most expensive portion of a "single-use" composite-propellant rocket motor is the labor required to assemble it. Qualified technicians who assemble rocket motors don't come cheap. With a "reloadable" rocket engine, you provide the labor to assemble it.

Another expense in a single-use motor is the phenolic plastic case that holds the propellant. Every time you fly a single-use motor, you have to get a new phenolic case too. Doesn't it make sense that if you use the case over and over that you'll rid yourself of that redundant expense? That's two ways you'll save money by using reloadable motors.

Here is the conclusion: the more times you reuse the reloadable motor, the more money you save! Tip: To calculate how much money you'll save with reloadable motors, see the Q&A article in Peak-of-Flight E-zine Newsletter issue #189.

In fact, most high-power rockets are flown with reloadable motors because the cost savings is so significant. You can start saving money too, even with mid-power size rocket engines.

Besides saving you money, the motors we offer have other advantages:

• They are legal in all 50 states and USA Territories!
  
  
• No Federal nor State Explosive Permits needed to possess or transport these motors.
  
  
• No "explosive storage magazine" required to store these motors in your house.
  
  
• We can ship them via the US Postal Service: That means there are NO expensive ($20) HAZMAT shipping fees!

There are some restrictions. To purchase and use any size reloadable motor, you must be at least 18 years old. This is a mandate by the government's Consumer Product Safety Commission (CPSC). The first time you purchase a reloadable motor from Apogee Components, you will be asked to fax or mail in a legal form of photo-ID (such as a driver's license) to prove you are at least 18 years old. Once you've proved your age, we'll remember your eligibility status for your future orders.

Each reload kit in the chart above uses a unique metal case (sometime called the hardware). The proper case part number is shown in each of the above charts. The metal case does NOT come with the propellant reload kits. It must be ordered separately.

To order cases, please click here.

The "E" power band, as the chart to the right shows, is greater than 20 Newton-seconds of Total Impulse, and less than 40 Newton-Seconds. The maximum power doubles from one letter to the next. So a "E" motor can have twice the power of a "D" motor; which means it will fly approximately twice as high.

An "E" motor isn't required to have the maximum of 40 N-s of total power to still be classified as an "E". It just has to have greater than 20 N-s but less than 40 N-s. This gives us the power-bands (shown as the colors in the chart to the right).

In our example, the E28-4T has 39.69 N-s of total impulse (from the table listed above). So it would considered a "Full" E motor since it is so close to the maximum of 40 N-s.

The first NUMBER after the power rating letter is the average thrust level of the rocket measured in Newtons. In the example case (E28-4T), the 28 means that it has an average thrust of 28 Newtons (a Newton is equivalent to 0.225 pounds of force).

The number after the dash is the delay time. In this example (E28-4T), the "4" tells us this motor has a four second ejection charge delay. That means that after the rocket takes off and the propellant is consumed, the delay charge burns for four seconds. This allows the rocket to coast into the air before the ejection charge pushes out the recovery device (either a streamer or a parachute). For more information on what to expect when you launch your rocket,
click here.

The letter after the delay time gives us an indication of the chemical propellant formulation used in the motor. See the image below to get an idea of what each formulation will look like:

T = Blue Thunder: produces a pale-blue flame, and wispy smoke.

W = White Lightning: produces a brilliant white flame, and dense white smoke.

J = Black Jack: creates dense black smoke that hides the flame.
FJ = Black Max: creates dense black smoke that hides the flame, more oomph than Black Jack

R = Redline: produces a vivid scarlet-red flame and white smoke. s

G = Mojave Green: produces an eerie green flame and white smoke.
M = Metalstorm
N = Warp Nine

Note: The "T" for the Blue Thunder formulation can cause a little confusion, since Estes use the "T" designation to indicate the size of the motor as being 13mm in diameter. See Estes Items for more about the "T". In either case, you can ignore the last letter since it doesn't really add much to the motor designation.

The Aerotech Easy Access™ motors have slightly different type nomenclature than listed above. The letter after the average thrust level indicates the propellant type. The letter after the dash tells the approximate delay time.

Here is an example: G77R-M

• "G" is the power classification of the motor. A "G" motor must have more than 80 N-s of power, and less than 160 N-s of power.
  
  
• "77" is the average thrust level in Newtons. The higher the number, the greater the kick off the launch pad.
  
  
• "R" is the propellant type. In this case, it is the Redline™ propellant formulation.
  
  
• -M" is the approximate delay time. An "M" means medium delay, which is approximately 10 seconds. If it was an "S", it would be a short delay (approximately 6 seconds). An "L" would be a long delay (approximately 14 seconds).
  
  Why the approximation for the delay time? Because the actual delay can be altered slightly by the assembly of the rocket engine. Getting a little grease from the o-rings on the delay can affect how it burns, so that is why it is an approximation. If you need something more exact, you should consider using a timer or altimeter-based ejection charge system.

If you have any questions about the motor designations, please give us a call, or send us an email.

Even though they are not classified as explosives, some Aerotech Mid-Power motors currently require shipment through a certified hazmat carrier (such as FedEx-Ground, or UPS-Ground). This is because the motors either contain more than 30-grams of propellant, or because they are not certified to be shipped through the US Postal Service.

Both carriers require the motors be marked as hazmat, and because of that, they charge a $25 per box hazmat fee. Unfortunately, we cannot do anything about this, even if you order just one single motor. Sorry, but the the per box fee is the same.

Because of this, it makes sense to order as many large motors as possible to leverage the Hazmat fee. You may ask your friends in your club if they would want to go in with you on your order to minimize the effect of the Hazmat fee.

The one piece of good news is that FedEx-Ground and UPS-Ground are quicker shipping boxes to you than is the government. And it is far easier to track it trough the system from our dock to your front porch.

When you order these motors, you will be charged one Hazmat fee per box. Most boxes can fit 6 motors in them, although in the shorter sizes we can fit more. If additional HazMat fees are required, you will be contacted by our staff. If you have any questions, you are welcome to call us at: 719-535-9335.

NOTE: We cannot ship HAZMAT outside of the United States, to Hawaii, Alaska, or any US Protectorate.

Also, there MUST be someone 18 years of age or older at the time of delivery to sign for the package. If there's a chance you won't be home, have it delivered to your place of work.

There are two restrictions.

1. To purchase and use any size reloadable motor, you must be at least 18 years old. This is a mandate by the government's Consumer Product Safety Commission (CPSC). The first time you purchase a reloadable motor from Apogee Components, you will be asked to fax or mail in a legal form of photo-ID (such as a driver's license) to prove you are at least 18 years old. Once you've proved your age, we'll remember your eligibility status for your future orders.
   
   
2. You must already have your "Level 1" high-power certification. Click Here to see how to get certified (coming soon).

"How easy is it to put together a reloadable motor from Aerotech?" That is a question that we hear a lot. It is not difficult. But in case you don't believe me, please watch the YouTube video on this web page. It will show you that they go together in about 5 minutes without having to use any special tools.

Q. Is it simple to use a reloadable motor?

A. Like anything in rocketry, there is a learning curve. There is a proper sequence of assembly steps, each with a verification step (to check for quality control). If you follow these steps (for both assembly and disassembly) with proper cleaning, you will find that it is fairly easy to assemble a reloadable rocket engine. Watch the video on this web page and judge for yourself if it is easy or not. We think you'll find that it is straight-forward if you follow the instructions.

Q. It is safe and reliable?

A. Yes, if you use them as prescribed by the detailed instructions.

Reloadable rocket motors are designed to be rugged and safe. If you assemble them incorrectly, they are designed to spit out the aft closure (where the nozzle is held in place). Once this happens, the pressure inside the motor is released, and most times the propellant will completely stop burning.

Q. When should I switch from single-use motors and use the reloadable variety?

A. As soon as you are sure you won't stop flying rockets (we all know how addictive they are). The metal case, into which you insert the propellant grains, takes a commitment to purchase because of the initial expense. You must look at it as an investment that pays for itself over time (like the RockSim software), because of the reduced cost per flight for the reload propellant grains.

Q. When should I avoid using a reloadable motor?

A. Reloadable motors are not for everyone. If you're under 18 years old, you may not use them.

There are also some situations where it is advisable to use a single-use motor, like the Apogee Medalist or Econojet motors. The biggest reason to use a single-use motor is in a rocket where there is a higher than average chance that the rocket will be lost after the flight. For example, launching the high-flying Apogee Aspire kit, which can easily go over 1 mile high and become a tiny speck in the sky, is a good place to use a single-use motor. This is the major reason why we at Apogee Components, do not sell the 18mm reload casing; there is just too high of a chance of losing the rocket on each flight.

Other "not-recommended" situations are when the launch area is surrounded by thick forests and/or lots of water. If you lose the rocket, you've lost the expensive metal reload casing.

You might not want to use a reloadable motor in contests, where you want to keep the rocket light. Typically, a single-use motor will be lighter in weight, and should allow the rocket to fly higher and stay in the air longer.

Finally, if you are in a time-crunch, such as working on a school project where you have to fly the same rocket multiple time in a single day, you might want to avoid a reloadable motor. The reason is that it can take a significant amount of time to clean and reload the casing after each flight. The weather may change quickly on you during those periods of prepping for flight. Also, when you are stressed for time, you are more apt to make an assembly mistake that could cause you to crash the rocket.

Q. Will reloadable motors work and will they even fit into my "built" kits that I already own?

A. Yes. For more information on the case sizes and how they are designed to fit into your existing kits, please see the FAQ's on the casings page.

Q. How do you select the right reload motor to use?

A.You select a reload motor based on the rocket you intend to fly and it's mission objective. This is exactly the same way you'd choose a single-use motor.

Start by using the RockSim software. Create or load-in your rocket design, then try out various motors until you find the right one that will keep the rocket safe and will meet the mission objectives. I highly recommend reading Technical Publication #28, which describes the procedure for selecting motors.

Q. Can I make my own metal cases?

A. Not recommended. Each reloadable case is precision engineered and manufactured to exact specifications using high-grade aerospace materials. They are made this way to be safe and reliable. Why? Because, if they should fail because of improper assembly, they need to burst open in a pre-designed manner that won't cause harm to spectators. Safety is everything in model rocketry!

Q. Is the rocket fuel (propellant grains) interchangeable between motor casings?

A. No. Each type of propellant grain is made to be loaded in a specific metal case. The reason is that the grains are different geometries (some have holes, some have slots) and are different sizes. They each burn differently which affect how much thrust they create. Additionally, the grains must be matched to the correct rocket nozzle so they create the proper amount of pressure inside the metal case. Too much pressure and the case will burst the aft bulkhead. Too little pressure and the motor will not make enough thrust to lift the rocket safely into the air. In other words, there is no such thing as a "generic" reload case.

Q. Can I make my own reload propellant (such as black-powder) and put it into the metal reload casing?

A. No. Black powder is classified as an explosive. The metal reload case is not designed to hold explosives like black powder. It will burst open in an uncontrolled manner. This is highly dangerous!

Q. Can I reload a single-use motor with the reloadable propellant grains?

A. No. During the "burn," the inside of a single-use case is severely charred and eaten away. The nozzle also erodes and changes shape. Should you try to reload the case, it will burst open and could cause you harm. This is why the NAR safety code prohibits modelers from doing this dangerous activity.

Q. What does "Easy Access" mean?

A. It is Aerotech's designation for reloadable rocket motors where the individual propellant grains weigh 30 grams. Why is 30 grams an important number? That is the maximum amount of propellant that is shippable through the postal system. If the fuel grains weigh over 30 grams, they cannot be shipped through the postal system; they would have to go via UPS or FedEx. These companies charge a hazmat fee ($20 per box) for shipping flammable items like rocket propellant. By keeping the propellant grains under 30 grams, you save money by avoiding a hazmat fee.

Note: the 30 grams is the maximum weight of the individual propellant grains. Many of the Easy Access™ motors use multiple grains (two or more slugs of propellant); which is why the total propellant weight inside the motor is greater than 30 grams.

Q. Why don't you ship rocket motors to countries outside the USA?

A. There are too many shipping regulations. We're a small company, and we don't have the manpower to track the regulations for each country in the world. So to keep our prices as low as possible, we only ship motors to USA customers.

Q. Can you ship motors to me by this weekend?

A. All rocket motors must be shipped by surface transportation (truck). While we ship the motors usually the same day the order comes in, you should plan extra time for the postal service to deliver them via third class mail (Parcel Post).

Q. How is maximum lift-off weight determined?

A. The maximum recommended lift-off weight for each delay depends on the size of the rocket, its drag coefficient, launch angle, and the wind conditions at launch. We recommend running a RockSim computer simulation for each rocket design and launch conditions to select the proper motor delay. For help selecting the correct delay time, see Apogee Technical Publication #28.

Q. What launch controller can I use to ignite the motors?

A. We offer two different controllers that can be used for mid-power size rockets. The Aerotech Interlock and the Pratt Hobbies GO-BOX Controller.

Q. Which igniters should I buy for these larger composite propellant motors?

A. Get the First Fire Jr.™ igniters. Click Here for more information.

Q. What is Recovery Wadding, and why do I need it?

A. Click Here for more information about Recovery Wadding.

Q. What kind of hook should I use to hold the 29mm reloadable engines in my rocket?

A. Aero Pack Engine Retainers. These are useful on rockets that use the 29mm diameter reloadable motors. And yes, they can be installed on existing rocket kits.

Q. How do you stage composite propellant motors?

A. You need some extra equipment in the rocket. We call them staging electronics.