I designed this rocket with simplicity and weather tolerance in mind. I utilized the spiralize printing technique and minimal fin area to reduce the wind effect on rocket trajectory without sacrificing stability. I used RockSim to validate the design. Result is a lightweight model rocket that can fly using an 18mm Estes A8-3, B4-4, B6-4, & C6-5. I have used a 12in parachute or a 1.25 x 36in streamer for recovery. This rocket is 20in long making it easy to see. Low parts count and simple assembly make it a fun project.
Things you will need besides printed parts:
-Small screw eye for nose cone
-18" of 300# test Kevlar kite line
-18" of elastic shock chord
-1.25" x 36" streamer for recovery or 12" Estes Parachute
-(1) Small Fishing Swivel
You will need to print (1) Nose cone, (1) Body Tube, (1) Coupler, (1) Fin can, (1) mount, & (1) clip. I set the shell thickness to 0.72mm. I set the infill to 100% for the nose cone and clip.
Once printed, trial fit parts together. Nose cone should be a nice slip fit. The coupler should fit snug into the body tube & fin fan. The mount should also fit snug into the fin can.
I use Gorilla glue super glue to glue together. I lightly sand the mating surfaces to rough them up. 1st, glue the coupler into the fin can and front fin can. It is 2in long and should be centered.
Tie the kevlar line to the motor clip. Tie the elastic to the Kevlar string. I used 300# test Kevlar kite line. I also put a piece of heat shrink tubing over the knot for added security.
Glue the motor clip to the motor mount. Glue securely!! Align the motor clip opposite the launch guide tube on the lower fin can and push into place to test fit. If all is good glue securely place. The mount has a notch to guide the Kevlar. Push the mount in until it is flush with the back of the fin can. The motor will stick out of the back 1/2". The mount clip will stick out about 0.75".
The coupler joins the body tube to the fin can. The joint should be centered in the coupler.
Slide the shock chord through the body tube and glue the body tube to the fin can. Make sure that the tubes are aligned, the launch lugs are aligned, and the rocket rolls without wobble on a flat surface.
Screw in the small screw eye into the nose cone. Tie the elastic shock chord to the nose cone using a bowline. Leave a small loop so the elastic is knot isn't tight to the screw eye.
For recovery, use either a Estes 12in parachute or a 1" x 30" streamer. I use a small fishing swivel to keep the tangles down and to make the recovery switchable.
Congratulations!!! Your new rocket is complete!!
Please see the recommended rocket engines for this rocket. I use (4) squares of recovery wadding to protect the recovery parachute or streamer. Check the balance and refer to the pictures for the proper location.
Good luck and safe flying.