How to build a rocket model

• Rocket model should have minimum diameter to contain the motor for peak altitude
• Longer rocket enables smaller fin area for any given stability
• Lighter isn’t always better, every rocket has an optimum mass
  • Motors with very short burn times have a greater optimum mass than motors with long burn times
• A thinner rocket produces less wave drag than a thicker one
  • Theoretically, super-thin rockets can have structural issues
• Limiting factors for length and diameter are carrying a specific payload or the dimensions of your engine
• If carrying a payload, put the weight towards the front of the rocket to move the CofG upwards
  • Longer the rocket, the smaller fins needed
• Start with a 10:1 fineness ratio when building a rocket model
• Use OpenRocket which has an optimization feature determining the dimensions for the builder.

• For a basic rocket that goes 1000 feet, you don’t need anything complicated like sensors or electronics.
  • Designed correctly, the rocket’s path will be controlled passively by its natural response.
• To build a small rocket that could get up to about 1000 feet, ignoring the rocket body itself, you need:
  • Motor mount kit
  • Model rocket motor
  • Parachute or plastic and embroidery string to make a parachute from
  • Body tube
  • Plastic nosecone that fits body tube
  • Balsa wood to cut fins from
  • Shock cord
  • Supplies: wood glue, craft knife, sandpaper, finishing supplies like primer and spray paint if you want to paint it
• A launch pad and a launch controller are needed.
• One should consider starting with building/flying a known-good design, then design/build/fly your own design.
  • The Estes Alpha is a classic rocket that would be a good fit here.
• Building an OpenRocket model at the same time with a few kits can weigh each part and override the weight of each part in your simulation model.
• Once completed, both the kit and the simulation model, then you can fly the simulation numerous times with different motors and under different conditions to watch what happens. This will give you the best chance of a successful flight and recovery.
• When ready to move beyond the basics, Handbook of Model Rocketry by Stine & Stine and “Make: Rockets” by Mike Westerfield with three goals is recommended.
• Reddit users suggested some additional tips:
  • Go to dollar tree/Walmart toy section for long pool squirt guns for body tubes.
  • Cut egg cups, Christmas tree ornaments make great nose cones.
  • Use extra long hair bands or elastic from the sewing section for shock cord material.
  • Go to an auto parts store or any mechanic shop and ask them if they have any used wiper blades. Rip the rubber off the blades and the metal strips holding the rubber are actually great for making engine stops just like the ones they sell in kits.

• The principle of building rockets is the same all over, and a simple Estes rocket found in a hobby store is a great place to start.
  • There are 100 different techniques people use, and it’s recommended to simply begin building kits to figure out what works best for you.
• Apogee Components provides educational videos on different aspects of building rockets.
  • It’s better to first build pre-made sets sold on Estes or Apogee to get a feel for all the components to design your own rocket later on.
• Motors are classified by total impulse, with the motors classified only up to “G” class.
  • There is a letter and number pair, followed by a hyphen and a number that tells you how strong the motor is and how long before a black powder charge pops the rocket.
• OpenRocket is a free program that lets you add every component of your rocket and simulate how that flight would go.
  • There’s a lot of studying to do to know all the ins and outs of getting an accurate prediction.
• NASA has an annual competition called the Student Launch, and schools are selected to compete by designing a rocket that flies to a specific height, with a rover/drone that has a task of collecting soil, etc.
• Build a water rocket to understand the basics of building a rocket.

• Description: Advice for thickness of rocket fins made of balsa wood.

  • 1.5mm thickness is available.

    • Two boards of 1.5mm thickness could be sandwiched together to create double the thickness and provide more strength.

    • For low-power rockets, single 1.5mm thickness is fine.

    • For an E45 rocket, 6mm basswood or 3mm marine plywood fins with large root chord are recommended.

    • Type of balsa used also affects fin strength; wind turbine industry has impacted availability and quality.

  • Fin Flutter Calculation should be performed for expected flight conditions.

    • This helps determine if the fins are strong enough.

    • Using a laminar flow airfoil template when creating fins can help.

  • Recommended resources for building rocket models:

    • The Beginner’s Guide to Rockets by Mike Westerfield.

    • Apogee Rockets Education Downloads (various topics available).

• Questions about building a model rocket
  • Building a liquid fuel rocket is not easy, requires time and thousands of dollars
  • Machining cost is relatively constant regardless of size
  • 3D printing and casting may be used for complex parts with little machining afterwards
  • Best option for small scale is solid fuel due to higher thrust to weight ratio
  • Regulations and commercial availability of motors and parts differ a lot from country to country
  • Model rockets use only commercially produced motors, available in the US and Canada
  • Weight limit of 1500 g on the pad, no more than 125 g of propellant, limit of 80 N of average thrust and no more than 160 Ns of impulse
  • Building your own motors is considered “experimental”
  • In Europe rocket companies usually hire locals due to laws and usually require experience
  • Only 2 major “companies” related to space in Europe: ESA and Arianespace
  • Doing it solo would be very difficult if you would like to see your design fly eventually

💭  Looking into

What are the safety regulations for launching model rockets?

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What is the maximum height model rockets can reach without a permit?

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What types of Estes rocket kits are most suitable for beginners?

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How thick should cardstock or plastic be for model rocket body tubes?

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How thick should the balsa wood be for model rocket fins?

• Webpage: Best model rocket kits of 2023
  • Rocket kits are good for all ages and occupations
  • Different kits suit different skill levels
  • Some kits are for blasting off, while others are just for building
  • Consider the age of the user before buying a rocket kit
  • Check the space required to launch the rocket before buying
  • Safety features should be considered, especially with young children
  • Best overall: LEGO NASA Apollo Saturn V
    • 1969 pieces, three removable rocket stages, and two mini-figures
  • Best LEGO: LEGO Star Wars Ultimate Millennium Falcon
    • 7,541-piece model, comes with two crews of mini-figures, an engine room, two escape pod hatches, a removable hull panel, a boarding ramp, and blaster cannon
  • Best for kids: Original Stomp Rocket Jr. Glow Rocket
    • Foam-rocket toy that teaches the basics of force and trajectory
    • Simple enough for even the littlest kids to operate
  • Best for experiments: Playz KABOOM! Science Kit for Kids
    • Designed for kids ages eight and up
    • DIY rockets, fizzy bombs, color explosions, and helium balloon bombs for a variety of experiments
  • Best budget: 4M Water Rocket Kit
    • Transform a simple soda bottle into a high-powered water rocket with just a bicycle pump and water
    • Safe and simple at-home kit
  • FAQs:
    • Is it legal to launch model rockets?
      • Yes, these picks aren’t powered by propellant, so you don’t need to worry about breaking the law when launching your rocket
    • What is the maximum height model rockets can reach without a permit?
      • Any rocket that goes above 150 km, or 93.2 miles, into the air, is no longer classified as an amateur rocket and will face more restrictions than one which flies lower
      • Most model rocket kits fly far below this limit, so you shouldn’t need to worry.
    • What model rocket goes the highest?
      • The highest-flying model rocket was created by the Civilian Space eXploration team. They flew it to 72 miles high a height in 2004.
  • Conclusion:
    • Rocket kits give practical STEM practice while getting kids outside and away from the screen

• To get started building a model rocket, building an Estes kit is recommended.

  • Estes Rockets offers a technical manual that answers several common questions.

• OpenRocket is a free simulation software for computer that is great for planning and simulating model rockets.

• Best to start with an easy Estes kit, like an astrocam or an alpha 3, and then move on from there to level 1 kits, figuring out build techniques like laminating fins and stuff.

  • LOC Park Fliers, Rocketarium, and Semroc kits are good for learning “through the wall” techniques and things like baffles.

• Learning something like Openrocket by cloning old rocket kits (search for like “fat boy plans” or “estes exocet plans”) would be the next step towards designing rockets.

• Mentors and organizations like NAR and Tripoli chapters can be very helpful, especially for students.

• The book “Make: Rockets, Down to Earth Rocket Science” is a great learning place as well.

• The best way to make a model rock cost-effective is to start with kits.

• Materials to use for the body, engine, and fins of a model rocket have not been mentioned.

• None of the comments mention specific design and simulation software to consider when building a model rocket.

• Reddit post on how to build a model rocket
  • Use Estes rocket kits to start with as they are affordable and include instructions
  • apogeerockets.com has tutorials
  • Openrocket (free) and Rocksim (paid) are software alternatives to plan and build rockets
  • For materials:
    • Use balsa wood for fins
    • Use cardstock or plastic for body tubes
    • Engines come in different sizes and classifications, such as A, B, C, D, and E; there are loads of options based on rocket size and power needed
  • Go to your local hobby shop for beginner-friendly Estes kit and basic materials
  • Follow NAR safety code
  • Join a local NAR club for mentors and liability insurance
  • Make: Rockets by Mike Westerfield is a good book on designing non-kit rockets and using OpenRocket software.
  • Some helpful websites:
    • www.thrustcurve.org
    • www.aerorocket.com/finsim.html
    • www.rasaero.com/
    • www.openrocket.info/
  • Common beginner mistakes:
    • Not following instructions
    • Not sealing the fins
    • Not using enough glue
    • Overpainting the rocket
    • Unbalanced rocket design
  • Keep an eye on costs to make it cost-effective

• Reddit Post: “I need first-time help with DIY rockets”
  • Suggestions:
    • Most rockets that size are made of paper tubes
      • Check out local hobby or craft store for Estes kits
      • Kits are cheap (~$20)
      • Can get a launchpad for a similar price
    • Once you understand how to build with kits, you can make them from scrap for free
    • Verify custom designs in simulation software like OpenRocket first
  • Disagreements:
    • User’s successful experience with 3D printed rockets
      • Design for printing lightweight and verify with a simulation
      • Can print safe rockets for low power
    • 3D printed rockets can be heavier and ill-suited for instantaneous shock loads
      • Fin alignment jig can be printed
  • Recommendations:
    • Read Estes’ Model Rocket Technical Manual
    • Read “Make: Rockets” by Mike Westerfield
      • Understand design and work through building a non-kit rocket
      • Learn to use free OpenRocket design simulation software
    • Purchase Alpha 3 or Big Bertha Estes models for low power

• How to Build a Model Rocket
  • Start with an Estes kit or another basic model rocketry kit available at your local hobby shop
    • These kits include instructions and are affordable
  • Get interested and move to more advanced rockets
  • Download software programs to plan and build rockets
    • Recommend SpaceCAD
      • $80 and includes a database that has almost every sort of engine, parachute, nose cone, etc. on the market
      • Simulate launches
  • Launch pads are sold separately if you don’t have a model rocketry club close by
  • It’s best to start small with kits before moving on to using software and making stronger, more powerful rockets

💭  Looking into

What is the best rocket model to build?