This is the story of how I built a model rocket from the ground up. From the electronics to the airframe to the 3d printed parts, this rocket has taken me six months so far, and is still a work in progress. Read on to learn how I got to this point, and how you can get to a point like this as well.
This story starts back in December of 2022. I was finishing up an remote control (RC) car build I was working on for school, and I had an open slot in my schedule to work on another project. I was watching a lot of BPS.space during this time, and I wanted to be able to do similar things. So I set off on my journey building a rocket with a thrust vector control system.
What exactly is thrust vector control? Now, I am nowhere near qualified to explain this in professional terms, but to me, it means “pointing the engine in a specific direction to control the rocket’s direction”. It goes a lot deeper than this, obviously, but that’s the surface level explanation. My goal was simple: Build a rocket that could utilize thrust vector control and active stabilization to slowly fly up into the air. I thought this would take me a few weeks to finish, maybe a month at most. Boy, was I wrong.
This project ended up being a six-month endeavor, and it’s still not done. I’m writing this article to document my progress thus far, and to explain to all of you how you can build your very own thrust vector control rocket. (and maybe in less time than it’s taking me!)
The materials and tools I needed to build my model rocket
- Airframe (I used 75mm BlueTube for my rocket)
- 3D printer (for the thrust vector control assembly)
- Various screws and bits
- Drill press (optional, for drilling holes in airframe)
- Belt sander (optional, for smoothing down the airframe when cutting)
- Note: All of my 3d printed parts were made of PETG
Buy the tools I needed here:
The first obstacle
This list may seem simple, but it took me a good month to acquire everything I needed for building the rocket. Unfortunately, I started off completely on the wrong foot. At first, I was dead-set on 3D printing 100% of the rocket’s airframe. But despite my efforts and my beautifully designed gimbal that was connected directly to the airframe, my Prusa printer broke halfway through this process, forcing me to look to alternative measures until the Prusa was fixed. Plastic would have also been significantly heavier and weaker than simply using BlueTube for my model rocket (which is the perfect blend of strength and weight).
Mixing my own fuel
I kind of shot myself in the foot with my second idea – mixing my own rocket fuel. Despite learning a lot from this process, I realized it wasn’t the right way to go. I spent two months and hundreds of dollars trying to produce my own rocket fuel, and even though the results were [pretty cool], it wasn’t something I could use in a rocket without adding another few months to the project; I would have to mill parts out of graphite, which simply isn’t possible with my setup. For this reason, I chose to ditch mixing my own fuel and decided upon using stock rocket engines.
Things finally start going right
After my first two failures, I changed my strategy and started to make progress. My mistakes convinced me I should use BlueTube and a stock rocket engine. Also, I didn’t want to lose more time designing yet another gimbal, so I decided to use the K-9 Gen 2 TVC Gimbal model available online. This model fit perfectly into my rocket airframe, and allowed me to shave some time off of the project, after the months I had already lost by “failing forward”. I printed this gimbal in PETG, if you want to learn how to do the same check out my article on how to print with PETG.
The (not) fun of PCB design
At this point, I had already decided that I was going to use my own circuit boards that I designed and built myself. If anything else, this would give me the knowledge necessary to design and build more complex PCBs in the future, and educate people on how to do the same. I designed the schematic in Fusion 360, which took only a few days, as I was already comfortable with schematic capture software, then pushed it to a PCB and started laying out all the parts.
That was when I met my first roadblock in PCB design:
When I was designing my schematic, I didn’t think about the physical constraints that I was working with. I chose parts that were way too big to fit on a reasonable-size circuit board, and many of the parts I chose were deprecated or out of stock nearly everywhere. This made it a huge challenge to get the board manufactured, especially at a size that I could fit in my model rocket.
However, I ended up finally being able to get these boards manufactured and shipped to my home after changing around my PCB design to use smaller, more compact components and taking into account physical limitations. This added another few weeks to the design process.
As of right now, that’s where my story ends. I’m waiting on the boards I designed to ship, and I will write an update article when they do and I make more progress on the rocket. For now, if you have any advice at all, please reach out or leave a comment on this article. Until next time!
