September 27, 2018
We have been so busy working on the hardware that we have forgotten to keep you guys up to date. To make it up to you, this post is going to be a tour of our rocket workshop.
There really is no such thing as a “rocket parts OEM”, outside of Boeing and Lockheed – and they generally prefer to sell their wares to the U.S. Govt. This lack of supply is because each and every rocket design is unique. A combustion chamber for one rocket motor probably will not work with another.
Typically, one needs to produce the part in-house, and this usually means that one needs access to a CNC machine and other advanced manufacturing tools. These machines are usually prohibitively expensive for small companies and teams, but we are fortunate enough to have one. Having one in our workshop allows us to rapidly produce our parts and prototypes, without needing to wait for a rapid prototyping service to get our parts back to us.
So what do we cut-up with our big fancy knife? Right now, it is our latest nozzle design, and soon some headers for our motor. Later, when we’re ready for flight, we will need it for our nose cone, fins, parts of our fuselage, plus countless smaller pieces we have not dreamed of yet. They all will require being machined on a system like this when pre-made alternatives can’t be found from a supplier.
This is one of our design stations. Designing a rocket takes a lot of math, and some pretty creative solutions. From the nose cone to the nozzle, every single system interacts with and affects all the others. A change in one system can affect the function of the entire rocket. This particular machine is meant primarily for mechanical and manufacturing design. Not pictured are the computers that are being programmed specifically to control and record data for our static ground tests, or each of our laptops and desktops that are used for more regular mechanical, electrical, and software design.
We elected to go with a hybrid motor, partly for their versatility, but mostly because the fuels tend to be less expensive, safer and gives us options for fuels that are more environmentally friendly.
Here, we have what will be one of the casings for our upcoming round of test fires. Simple cast iron for now, but we will be using a flight-friendly material in the future. The basic idea here is to spin the casing as the fuel is loaded into it, and allow centripetal force to form a 3-dimensional cylinder of fuel. This is called a “grain”, and they can have different internal geometries depending on the desired thrust profiles and the total mass flow rates. We will modify our grain’s geometries as we find the need.