AGM-12D Bullpup - Extreme Series Model Rocket Builder's Kit

Introduction:

The Extreme Series of Builders Kits were designed to print, assemble, and fly easily.  These rockets can be flown on lower-powered motors in a park, or with higher-powered 24/29mm motors.  Typically, an Estes F15 can loft these rockets to over 1000 ft, thus the name Extreme.  

The construction is simple.  This model includes a one-piece fincan with the fins attached.  The inside diameter of the fin can is designed to be lined with a 29mm motor tube.  Between this tube and the fin can is a small channel for a piece of kevlar kite string (~1mm thick).  This should also be epoxied in.  

Motor retention on this model is a little different than with other models in the Extreme series.  You will need a motor with an aft thrust ring, like Aerotech or Quest motors.  For Estes motors, I have included a thrust ring model that slips over the aft end of the motor.  It is a tight fit but it will slip on with some "encouragement".   The nose cone can be flown in two configurations, with the electronics sled or with the plug.  Both are identical except the plug does not incorporate the sled.  They will accept a ¼-20 eye-bolt.  Both include two holes for venting altimeters and routing e-matches for electronic deployment.

Also included is a detailed OpenRocket simulation file with potential motors that should work. 

If you print and enjoy this model, please consider clicking the LIKE (Heart) button and posting a Make.  It really helps me and I would love to see other models made from this. 

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I love designing, building, and launching rockets.  I also love giving back to the rocketing community.  However, filaments, printers, rocket motors, and parts aren't free.  By clicking on this link and contributing, you help me acquire the resources that keep this going.  You are under no obligation and everything here is free for you to download and use.  You can remix this stuff too.  Go nutz!  All I ask is that you tell 'em Frogglicker sent yas, and if you can afford a few dollery-doos, it really helps.

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If you have a need for a custom part or project, reach out to me.  I might be able to help you with a solution.

Models Included:

• Nosecone
• Nosecone Coupler
• One-piece Fincan - Requires support
• Tailcone Retainer
• Aft-end Thrust Ring for Estes 29mm BP Motors
• Tube Cutter
• Electronics Bay Sled
• Nosecone Plug
• 1010 Rail Guides and Buttons - Choose your preference

Note: I have included launch lugs, motor adapters, etc in my Extreme Series Accessories, though not all parts will work with this model

Materials Needed:

• BT60 Estes Body Tubing
• Approximately 6 ft or 1800mm of Kevlar shock cord – approx 1mm diameter.  I use Emma Kite String made of Kevlar from Amazon
• 29mm Motor Mount tubing (MMT) -  I use LOC tubes but Estes or Apogee will work too
• 15 (or more)-minute epoxy
• ¼-20 eye-bolt (or two) for the sled/plug
• 18in parachute and wadding or fire blankie
• OPTIONAL:  Reflective Tape and/or mylar strips as added streamer material – This rocket is small and hard to see when lofted over 1000 feet.

Building Guide:

Before starting, read this build guide.  If it's not clear, doesn't fit, or seems straight-up crazy, send me a message.  I am happy to answer any questions.  

Starting with the fin can, your motor tube (MMT) should be flush with the top of the coupler down to just before the threads (see illustration).  The motor thrust ring sits beyond the more narrow section.  The length of the MMT should be 100mm (reference red MMT in the picture below).  If the MMT extends aft into, or past the thread area, it will interfere with the tail cone retainer.  Dry fit your MMT into the fin can.  If you encounter moderate resistance, either sand the inside of the fin can or sand/peel the top layer of the motor tube until you can slide the tube in without kinking it.  If you kink the tube, the motor will not insert easily and can become jammed after flight.  

Once the dry fit is complete, run one end of your shock cord down from the forward end until about 25mm (1 in) is sticking out the back.  Apply a thin coat of epoxy to the aft end of the MMT and slide it in from the forward end until the tube is flush with the top of the fincan coupler and flush with end of the narrow part of the fincan (see illustration).  You must align the shock cord in the modeled internal channel to accommodate it.  Once the fincan MMT is locked in, you can trim the excess shock cord from the aft end of the fincan.

Next, you will need ~7-in (170mm) of Estes BT60 body tubing.  Use the included body tube cutter to trim off the desired length.  You can cut the tube back to the desired length after assembly.  Apply a film of epoxy to the inside aft end of the tube and slip it over the fin can.  Give the tube a little twist to make sure there's good coverage of epoxy on both the fincan coupler and the body tube.  Make sure to feed the shock cord through.

The Nosecone has a separate coupler that needs to be epoxied into the nosecone.  

Safety Police Disclaimer:  

Rocketry is a safe and rewarding hobby.  With knowledge and experience, you can experience the excitement of yeeting a rocket thousands of feet into the sky.  There is nothing else like it.  

Having said that, you are responsible for the rockets you fly.  If you build and fly one of these rockets, you should understand the NAR Safety Code and the potential risks involved with launching any rocket, especially these.  They were not designed to be toys.  They are real rockets that can potentially go very high and carry significant energy.  This rocket is intended to be built and flown by experienced rocketeers who understand the risks and can mitigate potential issues through experience.  By printing and flying this model, you do so at your own risk.  You are solely liable for any unexpected results and you agree to hold me and any manufacturer harmless of any liability.  I recommend you join NAR or Tripoli, join a club, and ask lots of questions.  Launching a rocket as a NAR/TRA member at a sanctioned event provides you with insurance you don't get at the park.  If you show up with one of my rockets, you're gonna make a friend! Money-back guaranteed :) 

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