To begin our design project, we decided to get comfortable, and gain understand with how our rocket will look and be made on SolidWorks. These designs are very basic but helped us get a foundation of how a more complex CAD design would look
Our process was simply to revolve a sketch of a rectangle with a right-angled triangle on top to give us the pointed rocket shape. We then simply sketched on four fins evenly spaced out and extruded them.
Connor was in charge of doing a CAD bottle and fins. Below are four designs, two with three fins and two with four. We later decided on having four fins for our rocket (see our decision making webpage). These CAD drawings gave us good visuals what our fins would look like once secured onto our bottle and allowed us to assembly the rocket with the nosecone so further modelling could take place (CAD modelling on SolidWorks using the flow simulator).
Hannah designed the nosecone. We used the equation 47.5*((1-((x^2)/(150^2)))^(1/2)) to create the curved line we wanted, then simply connected the end points to two lines at right angles to each other to complete the sketch, the longest of which we revolved the sketch about to form the 3D nosecone. We used 47.5mm as the radius, as that is the radius of the bottle our nosecone will attach to, so supplying a tight fit with minimal gaps between the rocket body and nosecone. The length we chose for the nosecone was 150mm is the as this would allow sufficient space inside to include a load (the parachute) and some added weight (to move the centre of mass closer to the nosecone to provide balance and stability during flight). The end of the nosecone is rounded, which was a choice based around the safety of our team when launching as well as spectators. Because it is not pointed, it is less likely to cause serious damage if an incident were to occur. It is also hollow for safety reasons, as well as to hold load, as it would be much less painful to be hit was a hollow nosecone than a solid one. This later led us to consider 3D printing when considering materials, as solid foam would be challenging to hollow out by hand.
We then did an assembly of the nosecone and bottle with the fins attached. This was useful to see the parts altogether and to be able to put it into the flow simulator to gain some data (see our CAD modelling page).
In order to attach the nosecone and bottle, we had to make an assembly and mate the two parts together, moving them until they fit exactly how we want, and then locking them into place.
