Australian Rocketry Pty Ltd

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Understanding Australian Rocketry Shop Categories

Model rocketry is not only educational, but a lot of fun too. Like many new activities, sometimes it can be a little bit daunting which can be discouraging. This guide is designed to help you with the basics of model rocketry and also how to navigate the Australian Rocketry online shop. This information will be updated from time to time, so make sure you check back regularly.

Gift Certificates – Looking for a present but don’t know what to buy? These vouchers are the perfect gift and can be redeemed by the purchaser or recipient of your choice.

Kits – Whether you are a beginner or more experienced flyers, Australian Rocketry has kits to suit everyone. There is everything from low power to serious high power, oddrocs (odd shaped rockets) and other assorted flying machines. The size refers to the main diameter of the rocket airframe.

Many kits come with everything that you need to fly excluding the launch controller, rod/rail and motors. Some more advanced kits require extra components, which is up to the individual flyer.

Accessories/Tools – This section contains many items that you will require to assemble your rocket or model. Everything from brushes, screwdrivers, cable ties, knives, PPE (personal protection equipment), measuring devices, clamps and tweezers, glues/resins and mixing equipment.

* We strongly recommend using the 2 part epoxies for structural integrity of mid power and above rockets.

* JB Weld is fantastic to adhere items that will be subject to high temperature such as motor retainers.

* Adjustable Density Expanding Foam is excellent for filling spaces such as TTW (through the wall) fin cans where there is a gap between the airframe and motor mount. This will also add bonding strength to the fins.

Hardware – Here you will find hardware components that you may require to launch to rocket. Basic launch controllers and rods, links for connecting shock cord, shear pins and rivets and launch lugs/buttons.

* Many clubs have rail launch systems often called 1010 (1inch) or 1515 (1.5inch). Rail buttons/linear rail lugs are recommended for all rockets that are >50mm (2inches) in diameter. You can put rail buttons on practically any size rocket, however just be careful when attaching that they do not interfere with any internal components eg. pistons.

Air Frames – Also known as ‘Body Tubes’, air frames are typically cylindrical tubes made from a variety of materials. Commercial rocketry components are based on standard sizes that have been around for many decades. Low power air frames are often made from light materials such as cardboard. Mid to high power air frames can also be made from cardboard, however these can be more easily damaged. Typically these are made from more durable materials as per below:

Phenolic – Resin induced card which although is slightly heavier than cardboard, is approximately 6 times stronger. Australian Rocketry stocks and supplies Public Missiles (PML) Phenolic tubes as they are the best quality available. Other brands have been tested, however sizes were often inconsistent. You can tell a PML tube as the logo is imprinted on the inside of the air frame. Phenolic tubes have spirals which may need to be filled for extremely smooth finishes.

Quantum Tube (QT) – This is a specially blended polymer tube which is very easy to work with. Unlike many PVC style pipes on the market, QT is not as brittle and withstand many hard knocks from flight. QT does not have any spiral grooves which allows for easy, immaculate finishes.

Fibreglass – More expensive and significantly heavier than other types of tubes, however extremely strong. Typically fibreglass air frames are used on high projects such as high speed, high ‘G force’ and larger projects. Many Level 3 Certification rockets are made with materials such as fibreglass. Fibreglass can also be used to strengthen other types of airframes such as phenolic and cardboard.

Carbon Fibre – Usually the most expensive type of tube available, however the lightest for the size. When unpainted, carbon fibre can make for a very attractive finish.

* Carbon fibre can cause shielding on tracking type electronics, causing issues with ground support and/or GPS locks etc.

Blue Tube – Made from vulcanised fibre, Blue Tube is extremely strong for a similar price to other materials.

* Blue Tube is recommended to be stored in an upright position and kept away from moisture.

Avionics Bays/Payloads – Made from the same materials as air frames, these components make it easier to install payloads such as electronic packages or cameras etc. Many dual deployment rockets that require two separation events for a drogue and main parachute will require an avionics to house the desired altimeter.

Payload bays can also be used to lengthen rockets to increase stability margins.

* Depending on what sort of product you select, the kit may contain items such as some airframe or switch band, coupler, rods, eye bolt/u-bolt, sled etc.

* It is important to install and configure avionics bays correctly. Many electronic packages require vent holes for barometric pressure sensors.

Centering Rings(CR)/Bulk Plates(BP) – CR’s are typically used to centre motor mounts into air frames. Depending on the length of the motor mount and arrangement of fins will determine how many CR’s should be used. A minimum of two (2) CR’s is usually required. For clustered motor mounts (more than one (1) motor), clustering centering rings (CLCR) are required.

BP’s are typically used to close off sections of tubes or the AFT end of a nose cone, or used as end caps on avionics bays. These are often great places to install eye bolts or u-bolts for attaching shock cord to.

Coupler CR’s and coupler BP’s (that are to be used in coupler tubes) are referred to as CCR and CBP.

Couplers – Made from the same materials as air frames, are smaller to fit into air frames ie. The outside diameter of a coupler should be the same as the inside diameter of the corresponding air frame. Couplers are typically used to lengthen air frames acting as a joiner for two (2) tubes. They are also used in avionics bays.

Electronics – There a number of different electronic components available including switches, mounting hardware, data acquisition cables, timers and avionics packages.

The most common electronics in rocketry are altimeters which are used primarily to calculate the altitude of a rocket and if capable and required, firing deployment charges for recovery events. Most altimeters will use barometric pressure sensors to measure the atmospheric pressure and/or accelerometers to measure the speed of the rocket. Combinations of these sensors and others will allow for various data acquisition and/or different events to be performed throughout the flight.

* Each altimeter has a description of its functions and capabilities. It is important to mount electronics in accordance with their relevant instructions to perform correctly.

* When using 9V batteries, we recommend using Duracell MN-1604 or MX-1604 batteries as they have welded internal components, which permits a higher level of stress during the rocket flight. It is important to understand what stresses may be on your rocket during flight to suitably pick the electronics package and battery.

Fins/Fin Material – Fins are often made from timbers such as balsa (low power) or plywood and fibreglass. Australian Rocketry sells sheets of balsa for low power and G10 fibreglass in a range of thicknesses which can be used to make suitable fins for any size rocket.

* Custom design fins or replacement fins from kits can also ordered as required. Australian Rocketry can cut fins to almost any shape or size.

Motor Mounts(MMT)/Accessories – MMTs are what your rocket motor is inserted into. These are usually the same materials and diameter as air frames excluding Quantum Tube.

Adaptors are required to use smaller diameter motors in larger MMTs eg. 54-38mm Adaptor will allow a 38mm rocket motor to be flown in a 54mm MMT.

Retainers are what we like to call an insurance policy and recommended to be purchased for every rocket. Low power retainers are often hooks that will keep the motor in the rocket when an ejection charge fires. Two (2) piece machined retainers are available for 18mm and up rocket motors and these are by far the best solution. With the MMT slightly protruding from the AFT end of rocket, one (1) piece is glued or bolted to the AFT centering ring on the rocket. Once the motor is inserted, the screw on cap is attached which allows for AFT retention throughout the flight. Rocket motors that are ejected from flight can be an expensive exercise for the flyer and also dangerous.

* Reloadable rocket motors usually have a slightly enlarged AFT closure which will act as forward retention. Low power and some mid power motors do not have a forward retention ring and will either require a ring to be attached or and engine block install to prevent the motor shooting through the rocket.

Nose Cones(NC) – Low power NCs are usually made from balsa or injection moulded plastics. Mid power and high power are made from plastics, urethanes or fibre glass. Different materials will offer different strengths and weights with hollow NCs sometimes allowing space for payloads (such as the intellicone) or additional weight to be added if required for rocket stability.

NCs come in different shapes and lengths which allow for different performance characteristics. For mid and high power rocketry, we have found Australian Rocketry’s Plastic NCs (PNC), to be the best on the market having withstood flights in excess of Mach 2.4.

Tailcones/Transitions –Tailcones/Transitions are used to create transitions of airframe sizes eg. Change the rocket diameter from 75mm (3”) to 54mm (2.1”). They can also be used to reduce the airframe diameter at the AFT end of the rocket which will help decrease overall drag in flight.

Another form of tailcone is known as a Boattail. These are generally shaped like a truncated nose cone and can often be slotted for fins to stick through.

Recovery – Here you will find everything required to safely return your rocket after deployment.

There are different types and sizes of shock cord (SC) including nylon, Kevlar, tubular nylon and elastic. The best type to use will depend on the size and weight of your rocket. Often referred to as the ‘recovery harness’, the rule of thumb for how much shock cord to use is 3:1 for low power rockets and 5:1 for mid and high power rockets.

Parachutes are the most common form of recovery and Australian Rocketry stocks a range of sizes for every size of rocket. Custom parachutes can be ordered on request. Most mid and high power rockets use a nylon material which is strong and durable. Many low power rocket kits contain either plastic or mylar parachutes which are relatively inexpensive, however often do not last as long as higher quality material parachutes. Nylon parachutes are also available for low power rockets.

Parachutes often contain a ‘spill hole’ which although allows some air to escape, also makes them stably float without swaying from side to side.

Streamers are also a commonly used form of recovery for small rockets and one type of drogue for dual deploy high power rockets. Streamers are also available in nylon or mylar. Streamers come in varying width and lengths.

Most parachutes and streamers deteriorate over time due to the hot ejection gases and flames caused by ejection charges. To help mitigate against these, Nomex blankets, pistons and baffle kits are great ways to help protect your recovery device. Recovery wadding is also handy to help protect parachutes and most clubs have this available for free at launches.

* When packing away your rocket for some time, it is a good idea to not leave your parachute packed inside the rocket. Often the parachutes can crease and remain in that shape when removed after long stagnant periods making them harder to deploy in future flights.

Motors – Rocket motors listed here are broken into two categories Single Use (SU) and Reloadable.

SU – There is two types of SU propellant available, Black Powder (BP) and Composite Propellant (APCP). SU means that once you have used the motor, they are a throw away item.

BP – Primarily low power motors and a small selection of mid power motors (A – E impulse motors). Typically these motors are 13mm, 18mm and 24mm in diameter.

APCP – These motors are far better in performance than BP motors and are designed for the high end low power and above rockets (D impulse and greater motors). Typically these motors are 18mm, 24mm and 29mm in diameter.

Reloadable – Reloadable motors use APCP and come as separate parts to be assembled into motor hardware (see Motor Hardware). Consumer reloadable motors range from D impulse through to O impulse, therefor cover high end low power all the way to high end high power. Typically these motors are 18mm, 24mm, 29mm, 38mm, 54mm, 75mm, 98mm and 152mm in diameter.

Reloadable rocket motors will generally stipulate what hardware is required to use that particular load.

Many motors below 75mm contain delay elements or smoke grains. The often can be adjusted down using the appropriate delay drilling/adaptor tool.

For more information about how rocket motors work, please see “How do Rockets Work?

For more information about the purchase and use of rocket motors in your local state, please see “Who can buy rocket motors?”

Motor Hardware – Machined aluminium cases are used to house reloadable rocket motors. The hardware will include a case (the tube), one or two closures and depending on the propellant manufacturer, sometimes a thrust ring, snap rings and nozzle washer.

When referring to a ‘Case’, that means the tube only. When referring to a ‘Motor’, that means all components required for that size hardware eg. If you own a 38mm 5grain motor, you could simply purchase a 38mm 3grain case and use the existing closures from your existing hardware.

Although some motor manufacturers make propellant that is interchangeable with other manufacturers hardware, this is not always the case and should be checked before attempting this.

Other accessories such as closure wrenches are recommended to make installing closures easier. Delay drilling/adaptor tools will allow you to change the length of the delay element in applicable motors. Certain reloads require the application of lube/grease which is also available.

Igniters/E-Matches – Igniters are used to initiate the rocket motor burn. E-Matches or Electric matches are used to activate ejection charges. Both items can be used for either purpose, although often may not always function correctly and should be avoided where possible. Some manufacturers have special mechanisms to help with the initiation of propellant and will often supply a suitable igniter.

These items are NOT detonators and under no circumstances should be referred to as such.