Mini 3d printed rocket engine

Solid rocket fuel:

ingredients:

Isopropyl alcohol
powder from various fireworks
sparkler powder

 
Incredibly unreliable but it works sometimes, sometimes it explodes when there is a bubble of air trapped in the mixture.

The base is 3d printed with multiple venting holes(see pictures below for demo) so that the heat isn't all directed on the PLA plastic. In the video one arm is broken.

Ignition happens with a fuse i got from a firecracker.

Testing was done on private terrain on new years eve!