Note: I used this rocket for my Google Science Fair project. I made a guidance system so my rocket would go perfectly perpendicular to the earth. Sadly, with all of the electronics and the weight of the motors, the rocket weighed one pound, which is too heavy for standard Estes rocket motors. If I were to launch this rocket, I would need a bigger rocket with a different launching system. I didn’t realize the weight problem until 3/23/11 after everything was constructed and I weighed the rocket. But this still looks cool! Feel free to build this rocket but build it as a model rocket, not a smart rocket.
Here is the link for the science fair project: https://sites.google.com/site/arduinorocket/
***Warning, I am not responsible for any problems that happen with launch or during construction! If you have any questions, please contact me!***
8.5″ x 11″ sheets of scrap paper
8.5″ x 11″ sheets of card stock
Elmer’s Glue All
Spent Estes rocket engine
Party Poppers tube (used as a form)
Ruler (both English and Metrics) with a straight edge
Tons of time (took me about 3 months)
Various salvaged parts
First thing I did was to make sure that the form that I was going to use would be able to hold all of the Guidance system components. The form is about 4″ wide. To give you fair warning, this is the only time that I will use the English system in this project! I needed to fit: an Arduino Mega, a solder-less breadboard, 4 small servos, two rocket engines, and a parachute. This 4″ tube is the perfect size for all of these parts, any larger of a tube and I can’t get this thing off of the ground.
The next thing to do is to remove everything that I put into the tube and start construction of the body tube. I didn’t want this rocket to be a tragedy like some of my other rockets that return to Earth in a cloud of smoke, especially if it is carrying an expensive equipment setup. I wrapped a large sheet of aluminum foil. This is fire proof enough to resist the backfire of a small Estes rocket engine. I glues the edge of the foil to itself and let it dry for about 5 minutes. I then started to wrap the foil with regular scrap sheets of paper. I let those dry a little bit but yet the tube was too weak. I wrapped the tube with card stock which gave it a little more strength, yet was still flimsy. Let the glue dry all the way and the tube will be just perfect. Then tape down the paper so it doesn’t come apart while the glue dries. Then I needed to make the upper section so there is a place where the accelerometer can sit. I did the same thing as I did for the regular body tube but I made sure that this part fit onto the body tube otherwise it would be too small and it would be scrap. You then glue that down and tape it up. Once the glue is a little dry you then use a full sheet of card stock and roll a cone out of that. You then glue, tape and set on the heater to let dry. I let it dry for about 2-3 hours. Once the glue was dry I then trimmed the excess paper off to make the rocket more aerodynamic and less stupid. This was all of the progress I made in one day. The next day I took everything off of the molding tubes to make sure that they were sturdy enough. I then removed all of the tape to make the paint job in the end a little easier. I removed the upper section to see if there were any deformities. There was. The glue seemed to dry kid of weird. Luckily there was a lid that I cut off of the molding tube to use as something to keep the circular geometry of the tube. I then went to work on the fins. I needed a basic fin that if moved could easily and effectively change the trajectory of a rocket if i were to go off course. Here is the design that I am going for: https://docs.google.com/drawings/edit?id=1-LgJl-WgplN-bz2WKhrX51sBu3Bz6xMgSkUNCWE1LOI&hl=en&authkey=COeVurgK
Here are the fins drawn and cut out:
After all of the fins were cut out and sanded I painted both the rocket and the fins at the same time. The colors I chose were Yellow for the fins and Silver for the body. I needed to see the rocket while it was coming down. While the paint and the clear coat was drying, I needed to build the engine tubes. I took one note card and rolled the card around the engine. I put one piece of masking tape on one of the long edges of the card and flipped it over. I put the engine on the other long edge and rolled. Once the Engine’s edge met the rest of the card I put glue on the rest of the card. I finished rolling, wiped the glue away, and smoothed out the tape so the tube held together while the glue dried.
After those dried, I cut holes in the engine/servo block. (Note, I used this rocket for my science fair project, there aren’t actually servos on the real rocket). I used my Dremel Tool for this job. If you don’t have a Dremel then you can use an Exacto knife. I traced the tube’s pattern onto the engine block. I then used the Dremel to cut and shape the holes. I then inserted the tubes and glued them in place.
Because I needed the rocket to control itself in 4 different directions, i needed eight fins. Four fins would be on the bottom and the other four would be just above them. I needed to rotate the top four fins 45 degrees so they can control the areas that the lower fins cannot control. Using Geometry I drew perpendicular lines and bisected the angles. To bisect an angle you put a compass at the vertex and draw an arc that intersects the two rays that form the angle (I just drew a circle since all the arcs would join to make a circle). I put the compass on the intersections and drew smaller arcs in the center of the angle. I repeated this to all of the angles until I had four “X” in the center of all of the angles. I then drew a line through all of the “X”. That gave me a perfect 45 degree rotation. I then Put my rocket on the circle and lied up the fins to the perpendicular lines. I then made marks for the 45 degree offset fins. I put the rocket up against a door frame to extend the line the whole length of the tube.
After the lines were drawn I had a problem. If the upper fins are rotated, then the backfire from the engines would not reach a parachute at the top of the rocket. I had to cut the lower section off and put a parachute there. After the tube was cut, then I marked and cut holes for the upper section of servos to move the fins.
Inside view of all the electronics:
Here is the completed rocket:
Construction completed: 3/20/11
I finished the Arduino code, just move your cursor over to My Rockets down to Phoenix 1 and then to the right to Arduino Code. Feel free to copy and paste it into your sketch (that’s the window where you write the code).