The Effect of Model Rocket Tube Length on Stability

Student: Forrest Wang
Table: 10
Experimentation location: Home
Regulated Research (Form 1c): No
Project continuation (Form 7): No



Works Cited:


All about Rocket Engines, Accessed 25 Oct. 2023. 

Gasmire, Charlie. “Best Materials to Make Model Rockets.” The Model Rocket, 7 Oct. 2020, 

Materials for Model Rockets - Ukra, Accessed 23 Oct. 2023. 

“Rocket Aerodynamics.” Science Learning Hub,,the%20right%20direction%20without%20wobbling). Accessed 23 Oct. 2023. 

Why Do Tall and Skinny Rockets Go Unstable? - Apogeerockets.Com, Accessed 26 Oct. 2023. 


Additional Project Information

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Presentation files:
Research paper:
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Project files

Research Plan:

Procedural plan 

  1. Take the 3 BT-55 body tubes and cut into a 2.5 inch piece with the cardboard cutter. 
  2. Attach the NC-55 nose cone to the body tube by snugly fitting the nose cone inside the body tube. (see Attach an engine hook to the engine mount on the outside with hot glue and attach the engine mount to the end of the body tube without the nose cone with hot glue. Cut out 4 pieces of foam board in the shape of parallelograms with a base of 0.25 inches and a height of 0.5 inches with 2 angles of 100 degrees and 2 angles of 80 degrees. 
  3. Attach the 4 fins to the model rocket with the 0.5 inch ends touching the body tube of the rocket. The fins should all be at 120 degree intervals and be at the end of the rocket with the engine mount, with the end of the 0.5 inch side touching the edge of the tubes. 
  4. Fit the B-engine into the engine tube and adjust to make sure it would not fall out ( glue or extra cardboard may be needed). 
  5. Repeat steps 1-6 three more times, each time with body tube lengths of 5, 10, and 15 inches, but make an extra 15-inch piece that could be attached to the other pieces via masking tape and hot glue. 
  6. Find the center of gravity of the rocket (this could be done by finding the single point where the rocket can balance on a thin object), and mark them with a pencil. 
  7. Tie a length of string around the center of gravity on the rocket, and use masking tape to make sure the string wouldn’t move. 
  8. Hold one end of the string in your hand, and start to swing the rocket, similar to how a lasso is swung (make sure this is done in an open area), whilst having a different person follow the rocket with a camera. 
  9. Repeat steps 8-15 five more times, with three of the five more times using the prolonged body tube. 


  • During swing test, model rocket may injure people 
  • Hot glue and sharp points on model rocket may injure people
  • Engine may be dangerous


  • Goggles should be worn during the swinging of the model rockets
  • Heat-resistant gloves should be worn during the process of making the model rockets
  • Keep model rocket engine away from flammable material or flames



Questions and Answers

1. What was the major objective of your project and what was your plan to achieve it? 

My main objective was to test how the length of a rocket could affect its stability and in doing so build my own model rockets. My plan to achieve this was to build multiple model rockets and use what’s known as a swing test to determine their stability. 

       a. Was that goal the result of any specific situation, experience, or problem you encountered?  

I’d say this was the result of multiple experiences. Going into this project I knew that I wanted to do something based on rockets due to me and my brother’s interest in this particular subject. I’ve always been interested in physics as a whole, but my curiosity towards model rocketry really increased when I attended a class on that subject while at a sleepaway camp. 

       b. Were you trying to solve a problem, answer a question, or test a hypothesis?

I was attempting to answer the question “how does the tube length of a model Rocket affect its stability?”

2. What were the major tasks you had to perform in order to complete your project?

For this project I needed to both build multiple functional rockets and  test their stability using the swing test (timing a piece of string onto their center of mass and swing them to simulate flying). 

       a. For teams, describe what each member worked on.

This project was done alone. 

3. What is new or novel about your project?

This project required the construction of a few model rockets for testing. I originally planned to buy serveral model Rocket kits and simply modify them, but found they were very expensive and very complicated to modify, so I instead opted to buy parts and build them myself. It was really interesting attempting to figure out the engineering kinks and problems as building something of this complexity wasn’t something that I had done before.

       a. Is there some aspect of your project's objective, or how you achieved it that you haven't done before?

Yes, that would be actually building something for this project. I have built things for projects before, but those were usually small components or simple modifications or just the attachment of a premade piece. However, for this project, I had to create something from scratch, and it was really challenging yet fun to make sure the models worked as I intended them to.

       b. Is your project's objective, or the way you implemented it, different from anything you have seen?

Though I have done quite a lot with model rocketry before (as mentioned in previous answers), this is my first time seeing and also doing a fully fleshed out experiment on the subject. 

       c. If you believe your work to be unique in some way, what research have you done to confirm that it is?

I’m sure that projects just like this and similar to this have been done before. In fact, one of the sources I used for my research was an article explaining the disadvantages of long rockets (it is the last source in my works cited). However, this is the first and only time that I have personally done something like this.  

4. What was the most challenging part of completing your project?

I’d say the most challenging part was building the model rockets. 

      a. What problems did you encounter, and how did you overcome them?

One problem that I faced was the engine being too small to fit into the body tube. In order to solve this problem, I had to make a makeshift engine mount with leftover pieces of cardboard and foam from making the rest of the rocket. 

Another such problem was the body tubes not being long enough to satisfy my needs (the body tubes I ordered were only 18 inches at their longest, but my experiment required 25 and 20-inch rockets), so I used pieces of foam and masking tape to prolong the body tubes. 

      b. What did you learn from overcoming these problems?

From this project I learned that when things just don’t work the way you want them to, you need to improvise to make it work. 

5. If you were going to do this project again, are there any things you would you do differently the next time?

I would 1) prepare materials more thoroughly (make sure I am ordering the right size and right amount of components) 2) research better before starting the experiment 3) start testing at higher levels. 

6. Did working on this project give you any ideas for other projects? 

I would possibly like to work on another project about the effect of the size and shape of fins on a rocket. I did use the same size and placement for all of the fins on the different models of rockets, but I would like to see what some slight variations could do to the rocket. 

7. How did COVID-19 affect the completion of your project?

It did not, as most of the work was done at home.