Apogee Components has decided to sell their equipment because of the high quality of the parts and ROUSE-TECH's commitment customer service.

The ROUSE-TECH reload casings are identical in size and fit to those made by Aerotech. They are licensed by Aerotech and endorsed for use with the Aerotech reload (propellant) kits. Basically, the only difference you'll notice is the color of the metal casing.

The aircraft-grade aluminum reload hardware consists of three parts: the case, the forward closure and the aft closure. Here is what each is used for:

The case holds the propellant inside. It is anodized yellow or bright blue to make it easy to find if it ever should fall to the ground.

The forward closure screws onto the front end of the case. It serves multiple purposes. First, it holds the hot gases of the burning propellant and keeps them from shooting forward into the body of the model rocket. It also holds the special slug of propellant called the "delay grain." Finally, it has a small receptacle at the tip to hold the black-powder ejection charge.

The aft closure screws onto the base of the aluminum case. It also performs several functions. Like the forward closure, it is a bulkhead that holds the hot gases inside the case so the motor can produce thrust. In the middle of the part there is a big hole, which allows the nozzle to protrude out the back end of the assembly.

There are two other features of the aft closure that make it convenient in most rockets. First, the diameter is bigger than the case. When you push the motor into the engine tube of the rocket kit, it stops when it butts up against the aft closure. In effect, it acts as the engine block. This way you can leave the engine block out of the kit if you want to use it with different length reload motors.

The aft closure also has two notches that can be used with conventional engine hooks. They would simply clip over the engine and nest inside one of the two notches.

Each metallic case was designed to be used with a limited number of reload (propellant) kits. The reason has to do with "rocket science" (the laws of physics) and with government and shipping regulations.

Aerotech designs the individual propellant kits to operate effectively within the dimensions of a specific size case. If the propellant is too short to fill up the case, the motor is inefficient because you're carrying excess weight into the air. If the propellant is too long, it may not even fit into the case. If the grain geometry is incorrect, it could over-pressurize the case and blow out the nozzle. If the nozzle size is too big, the rocket may not create enough thrust to lift the rocket. It is a delicate balancing act to design efficient motors.

Before ordering a reloadable hardware kit, check that the propellant kit you want will fit into that case. See the chart above. If you need help, please give us a call (719-535-9335).

The motor type in the chart above is not as confusing as it looks. The RMS stands for "Reloadable Motor System."

The first number after the dash is the diameter of the motor in millimeters.

The number after the slash (/) is the maximum total impulse that case would be able to hold. For example, a "RMS-29/120" is a motor that is 29mm in diameter and that can produce a maximum of 120 Newton-seconds of total thrust (G motor).

The RMS-29/40-120 case is designed to hold smaller motors, from an "E" to a "G" motor.

Note that the propellant kits designed for the RMS-29/120 (P/N 60005) are not interchangeable with the RMS-29/40-120 cases (P/N 60006). The cases look the same size, but they are significantly different.

In rocketry, you'll come to find that modelers describe everything in terms of Newton-seconds. If this concept is difficult to grasp, please give us a call. We'll be happy to help you out so that you can converse with the modelers in your area, without appearing to be a newbie.

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. Can I use the 24mm diameter reload engines in my current fleet of rocket kits?

A. Yes! If you compare the length of the Estes D12 motor to the RMS-24/40 case, it appears that the reloadable one will not fit. But, notice in the figure to the right that the RMS-24/40 motor steps down toward the right side (the forward end). That reduced diameter section is designed to slip through the engine block that you have in your rocket. In this way, you can insert the motor into rocket kits that you have already built. IT DOES FIT !

Q. What about the engine hook? How does it work with the RMS-24/40 case?

A. If you have an engine hook in your rocket, you'll find that it simply snaps over the back edge of the casing in one of the two gaps provided in the black ring on the back of the motor casing.

Q. If I leave the engine block and hook off the rocket, what keeps the rocket from sliding into the rocket?

A. The lip on the back of the motor butts against the aft edge of the engine tube. This prevents the motor from sliding forward. Cool, isn't it?

To prevent it from sliding aft, you have two options: 

1. You can put a layer of tape over the top. Click here for more information.

2. You can use an engine retainer as shown to the right. Click for information on Engine Retainers

Q. What kind of hook should I use to hold the 29mm reloadable engines in my rocket? I noticed that the Apogee web site doesn't have long engine hooks.

A. Engine Retainers. These are useful on rockets that use the 29mm diameter reloadable motors that are extra long.

Q. Can I make my own metal cases?

A. Not recommended. Each reloadable case is precision engineered and manufactured to exacting 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. How easy is it to assemble a reloadable rocket motor?

A. It will take you about 5 minutes to put one together. If you want to see how easy it is, watch our YouTube video where we put one together (click here).

Step 1: Pick the diameter of the engine. Clicking on the diameter will take you to more information about each diameter motor so you can select the correct casing.

• 24mm Dia. Motors (power: E - F )
• 29mm Dia. Motors (power: F - G )
• 29mm HPR Motors (power: G - I )
• 38mm Dia. Motors (power: G - J )
• 54mm Dia. Motors (power: I - K )
• 75mm Dia. Motors (power: K - M )
• 98mm Dia. Motors (power: K - N )

Step 2: Pick the Aerotech Propellant kit that you want to fly in your rocket. To be honest, this is the most time-consuming step. Contact us if you need help. We'll direct you to the RockSim software that we use to help pick the right rocket engines for your vehicle. Technical Publication #28 gives you a step-by-step procedure for picking the motors that might work in your rocket.

Step 3: Match the propellant kit that you just selected in step 2 to the appropriate Rouse-Tech Monster Motor Case.

The aluminum reloadable casing is also called the "reload hardware." Why not let Apogee Components be your hardware store?