Balerion Mk2A1

Introduction

This is a “kitbash” of sorts.  I took the best (IMHO) parts of each 3D project and smushed them together into a model rocket that just terrorizes the Colorado landscape.  This is a builder's kit in that you need to have a fair bit of experience building and flying model rockets, especially with higher-power motors.  This rocket can fly on ‘E’ class motors but it really shines in the F-G range.  Be safe and please follow the Model Rocket Safety Code set forth by NAR

Attribution

I would first like to thank Digbaddy, Vecinimod, Wardy89, and SiegeCraftPB for their contributions to this model.

Notes on Building

• You need to build the fin-can strong and light.  You should experiment with your infill types and density and refer to DigBaddy's original post.
• You should experiment with the density of the nose cone.  I came up with a center of gravity for this rocket that was very unstable and had to add ~ 50 grams of weight to the nose cone.  YMMV
• This is a heavy rocket for its size.  Do NOT use trash bag parachutes.  Use rip-stop nylon from a vendor, such as Top Flight

Things You Will Need:

• BT-60 Body Tube - I used ~180mm length but you can adjust using the attached OpenRocket Sim.
• 29mm Motor Mount Tubing - I cut mine at 12cm then trimmed excess
• 4-6 feet of 150# Kevlar cord - the rule of thumb is ~4x body lengths worth.
• ¼" Eye-hook
• 18-24" parachute - Colorado air is thin so I used a little bigger
• Epoxy (5 - 30min will work) or medium-thickness CA
• Rail buttons

Build Steps:

• Print all the parts.  The retainer file contains both short and tall caps.  I used the tall to accommodate the Aerotech S/U motors but having both is handy.
• Dry fit your parts and adjust accordingly.
• Dry fit the MMT in the fin-can.  The fin-can was modified to accommodate the 29mm MMT but it might be tight.  DO NOT force the MMT or you will wrinkle it and cause more work.  Either reprint with a wider opening or file out the fin-can until the tube slides in without force
• Be sure you understand how this goes together before reaching for the epoxy
• Add the shock cord to the fin-can.  I pulled enough length to wrap once around the bottom of the fin-can where the MMT extended.

These steps can be done together, if you plan ahead and use a slower-setting epoxy

• Join the MMT to the fin-can.  The forward end should be flush with the top of the fin-can and there should be enough excess to mount your motor retaining ring. 
• Wrap the shock cord around the MMT at the aft end of the fin-can and join the motor retaining ring (not the cap) snugly to the aft end of the fin-can
• Join the eye bolt to the avionics bay and lock it in place with epoxy on the threads, bolt, nut, and washer.
• When all is cured, feed the other end of the shock cord through the BT-60 body tube and join the body tube to the fin-can.
• Once everything is cured, join your nose cone and your parachute to the shock cord. 
• Test fit a 29mm motor or motor adapter (included in .STLs) to verify fit.
• Add weight to the nose cone to achieve a stability caliber of at least 1.  I try to shoot for 1.5.
• Add a rail button ~¼"  from the aft of the fin-can and a second one somewhere 1-3" from the top of the body tube. 

I have flown this once on an Estes E16-7.  It was a great flight except the delay was too long and shredded the chute.  It was lost in a field of ‘Wookie Grass’.  The Mk1A2 version will have a Top Flight chute with a tracking device attached.  

This rocket wants to fly on a G80-13.  It will go over 4000 feet, and you will lose sight of it, so tracking is important.  You might consider adding a shiny mylar streamer and a JollyLogic Chute Release.

When I build the next one, I will do it for YouTube and will post the link here.

If you build this, please post a picture or video to let me know how it went.