Creating and Testing my own Rocket Motors

This is a step-by-step walk-through of the process I use to make my own rocket motors, and the process for how I tested them. This motor is a PVC pipe packed with a fuel mixture of 65% potassium nitrate and 35% powdered sugar. The motor that I build here is the same as I usually make, except it has one difference - it has a plastic piece attached to the outside so that it can be put into my fully 3D printed rocket. This motor uses solid rocket fuel; I am currently working on creating a hybrid engine (combining solid and liquid fuel).

Step 1. I cut out the case for the motor from a long pvc pipe:

Step 2. I marked the screw holes on the sides of the caps, and the nozzle hole on the top of one of the caps. The nozzle is where the blast of the motor will come from:

Here are the three different drill bits I used; the largest one is for the nozzle, and the two smaller ones are for the two types of screws:

Step 3. I drilled all of the holes, screwed on the cap with the nozzle, and attached the plastic piece onto the case:

Step 4. I made the fuel for the rocket motor. It is 65% potassium nitrate, and 35% powdered sugar. I then mixed and sifted it:

Step 5. I poured and packed the fuel into the motor:

Step 6. I screwed the back cap onto the motor:

Step 7. I took the motor off of the rod, and it is done! Now it can be placed into the rocket for use.

Step 8. I made an igniter for this motor using a matchstick and two copper wires:

Here is the motor in action. It is very powerful:

Tests 1-3: In the first three tests, I had no end caps on the motor and experimented with clay and other materials to contain the pressure. I also experimented with putting an ejection charge into the motor, but that also didn't work. Regardless, all three first tests looked very similar to the video below, with the fuel breaking through any barriers and producing a lot of smoke, but virtually no power as there was no build-up of pressure inside the motor:

Test 4: For this test, I tried to make a cap using some metal that I cut and shaped. However, there were gaps, and so the flame was able to escape through these gaps, which set the entire motor on fire, as seen in the video and picture below:

Test 5: This was the first successful test (shown above as well), as I figured out that I should put PVC caps onto the PVC pipe. These caps leave no gaps and perfectly contain the pressure: