Introduction: Building a Model Rocket - Introduction

Building a model rocket is a fun pastime, but it can be easy for someone new to the hobby to make a mistake.  This guide is intended to help those who are new to the hobby complete all steps required to build a basic rocket called the Big Bertha.  This rocket can be purchased in most Hobby stores  Attached to this step are the safety guidelines for building a model rocket.

PRECAUTIONS AND WARNINGS
DO NOT ATTEMPT TO DEVIATE FROM THE GUIDELINES WHEN BUILDING THE ROCKET. THIS COULD CAUSE SERIOUS INJURY AS A RESULT OF FIRE.
During the assembly:
• Be sure to take all precautions necessary while using craft knives and glues (super glue, hot glue and other adhesives). These may include gloves and eye protection.

• Be sure to complete all operations in a brightly lit area with adequate ventilation.

• Although most glues are identified as non-hazardous according to OSHA standards, fumes and the glue itself can cause eye, skin and respiratory tract irritation. If irritation occurs, flush the affected area with clean water or move to an area of fresh air.

• For more information, refer to the MSDS sheet of your particular glue/adhesive.

During operation:
• Use safety goggles during all times of operation. Debris and hot gasses may cause irritation to the eyes.

• Always check the nosecone and fins for damage/cracks before each launch. Any asymmetry can cause the rocket to deviate drastically from its intended path which can result in injury.

• Make sure to use the rocket only outside and not in a confined area or poorly ventilated area. Fumes from the fuel can be hazardous to your health. If shortness of breath occurs, move to an area with fresh air. If the irritation persists, call necessary medical personnel.

• Keep all flammable materials away from the exhaust end of the rocket. High temperature flames will be ejected and this can start a fire.

• DO NOT ATTEMPT TO AIM THE ROCKET OR ROCKET EXHAUST AT ANYONE OR ANYTHING, HUMAN OR ANIMAL. This can result is serious injury from impact and burns.

• In case of fire a water spray, type A, B or C fire extinguisher can be used on the rocket itself. BE SURE TO KEEP THE APPROPRIATE EXTINGUISHER ON HAND FOR ANY OTHER FLAMMABLE MATERIALS NEARBY. In case of a major fire, do not attempt to extinguish the fire yourself. Evacuate the area and call 911.

Step 1: Materials

Before starting assembly, make sure you have the following materials.
• Engine Mount Tube
• Engine Hook
• Mylar Ring
• Green Engine Block
• Perforated Engine Bulkhead sheet
• Perforated Balsa fin Sheet
• Elastic Shock Cord
• Nose Cone
• Launch Lug
• Parachute
• Body Tube
• Fin Placement Guide-This is found in the Estes manual and needs to be cut out with scissors
• Shock Cord Mount- This is found in the Estes manual and needs to be cut out with scissors

Step 2: Tools Required

The following tools are required for assembly and can be seen in the figure below
• Scissors
• Pencil
• Ruler
• Fine Sand Paper
• Model Aircraft Glue
• Modeling Knife
• Masking Tape

Optional-If you want to paint your rocket
• Primer (Your choice of color)
• Paint (Your choice of color)

Step 3: 1. Assemble the Engine Mount

The following steps detail how to assemble the engine mount.  The engine mount is what attaches the rocket motor to the body tube of the rocket.

1.1. Mark three lines on the engine tube at ½ in, 1 ¼ in, and 2 ½ from either end of the tube (This end will be the bottom).

1.2. At the 2 ½ in mark, make a 1/8th in slit in the Engine Mount Tube with a modeling knife along the circumference of the tube.

1.3. Apply glue all the way around the Engine Mount Tube on the measured 1 1/4th in mark.

1.4. Insert the right angle end of the Engine Hook into the slit made in (1.2), lay the hook flat against the tube and glue.

1.5. Slide the Mylar Ring over the Engine Mount Tube and Engine Hook and onto the glue line.

1.6. Apply glue to the inside of the Engine Mount Tube on the side opposite of the Engine Hook and insert the Green Engine Block, open end into the tube.

1.7. Cut out the Centering rings.

1.8. Slide the Centering Rings over the Engine Mount Tube and align the ring with the notch at the ½ in line, and the ring without the notch at the very top of the tube.

1.9. Apply glue to both sides of both Centering Rings at their aligned positions.

Step 4: 2. Preparing the Fins

The fins are what help stabilize the rocket in flight.  The following steps show how to cut and sand the fins to prepare them to be attached to the rocket.

2.1.Carefully cut the Model Rocket Fins out of the Laser-Cut Balsa Sheet.

2.2. Sand the rough edges of the fins to remove any burrs.

2.3. Align the sides of all four fins, hold them together and sand the base of the fins (This just ensures that the fins are flat where they attach to the rocket).

Step 5: 3. Tube Marking

The fin marking guide found in the supplies for the Big Bertha rocket is a handy tool for aligning the fins.  The following steps detail how to mark the rocket body tube to prepare it for attaching the fins.

3.1. Cut out the Tube Marking Guide located on the Rocket Kit’s provided instruction Manual.

3.2. Tape the LL end of the Tube Marking Guide to one end of the rocket tube and wrap the guide around one side of the Body Tube. Finish by taping the FL side of the Tube Marking Guide to itself (this chosen end will be considered the bottom of the tube).

3.3. Place a mark with a pencil on both sides of each FL and LL line on the Body Tube.

3.4. Remove the Tube Marking Guide from the tube and extend all the lines by setting the tube in a right-angled channel (like a door frame), lining up the mark and sliding the pencil along the guide.

3.5. Put a small mark 4in from the bottom of the body tube on the LL line.

Step 6: 4. Install Engine Mount

Gluing the motor mount inside the rocket body is a crucial step.  The rocket motor creates a lot of force that travels through the motor mount to the rocket body.  It is important to make sure enough glue was applied to the edges of the mount to secure the mount to the body tube.

4.1. Apply glue to the edges of the centering rings of the motor mount. See the video below for more details.


4.2. Slide the Assembled Engine Mount into the bottom of the Body Tube with the Engine Hook towards the bottom until the bottom of the Engine Mount Tube is even with the bottom of the Body Tube.

4.3. Glue the joint between the lower centering ring and the rocket tube.

Step 7: 5. Attach Fins

After the fins have been sanded and the body tube has been marked the fins can be glued on.  It is important that the fins are straight so practicing aligning the fins with the rocket body may be helpful before using glue.

5.1. Glue the base of one fin along an FL line at the bottom of the rocket. Make sure the fin is square to the surface of the rocket body and aligned with the FL line. Hold the fins in place for a few seconds until the glue can hold the fins in place.

5.2. Repeat 5.2 for each fin.

5.3. Set the rocket upside down on a flat surface or over a pole and allow the fins to dry.

Step 8: 6. Attach Launch Lug

The launch lug is a tiny mount used to mount the rocket on the guide pole of the launch pad. 

6.1. Apply a line of glue from the 4” mark towards the top of the Body Tube the length of the Launch Lug.

6.2. Place the launch lug on the glue line and visually align it with the Body Tube.

Step 9: 7. Attach the Shock Cord

The shock cord is what attaches the nose cone to the body tube.  This is necessary so that the parachute can deploy.

7.1. Cut out the Shock Cord mount template located on the Rocket Kit’s provided instruction Manual

7.2. Alternatively, cut out a 2” x .75” rectangular piece of paper.

7.3. Glue one end of the Shock Cord to the center of the template (#2), with the shock cord aligned with the long edge of the template.

7.4. Fold up the end of the template (#1) over the shock cord.

7.5. Fold the #2 & #1 section over the Shock Cord and #3 section and glue.

7.6. Place the folded paper and shock cord under something heavy and allow the glue to set. Make sure to protect the heavy object with paper products.

7.7. Apply additional glue to one side of the shock cord packet and place it at least 1 ½” inside to the inner surface of the Body Tube from the top.This must be glued at least this far into the tube or else the Nose cone will not fit into the Body Tube.

7.8. Hold until the glue sets.

Step 10: 8. Assemble the Recovery System

The parachute is what allows the rocket to return to the ground in a safe fashion.  After the shock cord has been attached the parachute can also be tied to the nose cone.

8.1  Use the modeling knife to cut out the perforated hole at the bottom of the Nose Cone.

8.2. Untangle the Parachute and find the 3 loops at the bottom of the attachment points.

8.3. Pull these loops through the hole in the nose cone.

8.4. Pull the Parachute cords through the Nose Cone and insert the parachute through the loops.

8.5. Pull the Slip knot tight.

8.6. Tie the unattached end of the Shock Chord to the Nose Cone using a double knot.

8.7. Make sure the knot is placed towards the bottom of the nose cone to ensure clearance of the Nose Cone into the Body Tube.

Step 11: 9. Load the Recovery System

After the rocket engine has fired for a sufficient amount of time it launches a charge that pops the nosecone off and deploys the parachute.  To protect the parachute wadding (sold separately) is packed between the rocket motor and the parachute.


9.1. Carefully place 7 to 8 wadded up pieces of paper into the top of the Body Tube in a loose configuration.

9.2. Straighten out the parachute by tugging at the center of the parachute till it lays flat.

9.3. Fold the parachute in half by folding the center part of the parachute.

9.4. Roll the parachute up to the center from both sides.

9.5. Wrap the parachute lines around the rolled parachute loosely.

9.6. Insert the parachute into the top of the tube.

9.7. Pack the shock cord into the top of the Body Tube and then insert the nose cone into the top of the Body Tube.

9.8. You may paint your rocket any color you choose.  We chose to leave ours unpainted for a more retro look.

Step 12: 10. Enjoy

The rocket is complete! This is the end of construction of the rocket.  You are now in possession of a rocket that can is capable of flight.

For information on how to prepare the rocket for flight please visit this video courtesy of  Apogee Rockets http://www.youtube.com/watch?v=hC6evC1N05c . Please follow all safety instructions before launching your rocket.

Painted rocket image courtesy of Estes.