I tested a prototype rocket motor using a 35/65 KNSU propellant mixture cast to a 0.375" inner-diameter specification. Peak thrust reached approximately 115N with total impulse near 65N, placing the motor in the F-class range.

Motor test setup

Performance Highlights

  • Cost: ~$2.55 per firing (compared to $10-15 for commercial F-motors)
  • Notably quieter operation than previous tests
  • Forward closure remained sealed effectively
  • Nozzle exhibited acceptable char and ablation patterns

Post-burn nozzle 1

Post-burn nozzle 2

The nozzle construction used "Rockite" cement for the throat section with a PVC end-cap. Post-firing analysis revealed uniform ablation around the outer rim where expanding hot gases melted the surface material. This is consistent with high-velocity gas expansion characteristics.

Firing in action

Thrust curve

The test was deemed successful, with additional experiments planned for the following weekend exploring different throat diameters and design modifications.