Sugar Rocket components - Nozzle and nose

I'm working on a simple sugar rocket and I designed this nozzle starting from the most common nozzle shape I found on wikipedia (the converging-diverging nozzle).

You will need a PVC tube with an internal diameter of 22mm and external diameter of 25mm. I use glue to join the pieces, that's why you see grooves on them (they hold the glue).

To make the fuel I use a mixture of 60% KNO3 and 40% sugar.

It must be printed with a 3D resin printer. If you print it with PLA or ABS it will be melted by the extreme heat generated by the fuel.