Friday, 11 December 2015
OpenRocket and rocketry CNC workflow...
I've been playing with OpenRocket for a while now, essentially this little free java application allows you to design rockets and simulate their performance with an extensive database of rocket engines built in. It calculates both centre of gravity and centre of pressure and uses the Barrowman equations to calculate the stability (or lack of) in your design and has lots of aerodynamics code built in calculating drag coefficients etc. Being able to simulate launches and recovery is excellent and allows you to both optimise your design in terms of feasible altitude but also can allow you to fly within the limits of a particular altitude ceiling. Simulation also is important when you get up to qualifying certification flights for high power rocketry as your rocket needs to perform similarly in real life to what you have submitted in simulation data.
So all of this was exciting as I start to design my first scratch built rocket attempt, however an added excellent bonus is that Openrocket exports it's simulation data into a PDF document which I hadn't done until recently as I wanted to printout some data. The export function also will print out various other useful items from your design including fin templates and centring rings (rings that hold the inner engine tubes to the outer airframe tube) as PDF is a vector format it is readily accepted into most CAD/CAM environments and therefore it is a trivial matter to create tool paths to cut fins and rings etc on my CNC router. Slick!