Hey guys! It's been a few weeks since y'all last saw me (I was the guy who made that rocket motor that failed..). Anyways, I've completed my second motor, with several improvements on this go round.

Instead of pouring my fuel mixture directly into the body, I made pre poured fuel into cardboard sleeve- lined pvc tubes. This made removable fuel grains. This next motor will have around 260 grams of fuel.

The biggest improvement is in the nozzle. Last time, I had a pretty crappy nozzle with only a small divergent side. This time, I have improved the divergent side by getting a better fitted funnel for the mold, as well as a convergent end made that utilized a 1 inch pvc cap as the mold. I also added a steel washer that should maintain the exit hole diameter, even if the concrete part is destroyed.

Instead of a cement cap that was attached by a coupler and pvc glued on, the fuel body itself now contains the cement cap. I set 9 screws every half inch down the pipe for the cement to grip something other than just the walls of the container. Now, there will be no space in between the fuel and the cap, meaning that the pressure from the gases expelled should only go out the nozzle, and not out both ends like last time. Also, there is a quite a bit more concrete to seal it now, instead of the 1-1.5 in there were last time.

Instead of in a gutter, the next test will be on an open 40 acre farm. I will be much, much further back, as I have made an electrical firing system. I also have things ready to put out a fire, safety goggles, etc.

Instead of burying it or laying bricks, I'm gonna design built a rig to hold the rocket in place. This test will not measure force, just another test on how nozzle, cap, and body hold up to the pressures.

Improvements I need: I really need to find a different fuel. The 68% sugar 32% KNO3 burns great, but is an absolute pain to cast. It hardens immediately, making pouring and coring very hard. Doing research, I've found some formulas that call for corn syrup, and from what I've seen they're pretty fluid for casting.

I also might need to switch to aluminum casings in the future, if these next tests show pressure rated pvc to be insufficient.

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A little about this project..

The first motor wasn't supposed to be all that great. It was thrown together in a matter of a few hours for it to be fired on the fourth of July. The fuel casting wasn't great, the concrete was freshly poured, and there wasn't too much engineering on the thing (as you might have seen

). This next one should be much improved if the casing can hold up to the test.

Eventually I want to have precise fuel grains, a tough body that is light, improved nozzles, etc. I want to know exactly how much force I can expect from a fuel grain so I can classify my motors, calculate apogee, speed, etc. I also want to eventually get help from my EE friend with some electronics, including a camera onboard, altimeter, etc. This honestly might be a long way off, being in school and having work and such, but I can dream can't I?

Also, this is being done in my limited free time and on a college budget. I'm home from Auburn but I'm really trying to save everything I earn from my job for school. So, I don't have the money, time, or tools to make top notch motors right now, but I'll try my best with what I have.

Oh, and a LOT of y'all were confused by my use of "motor". A motor is by definition something that produces power or motion... therefore these can be classified as motors. It's also the term used by almost every amateur rocketry association, from Tripoli to model rocket makers like Estes. So that's why I call it a motor.

Anyways, the next video should be coming soon. I'll post on here and I hope y'all enjoy!

Also, shameless plug for my YouTube channel. Subscribe if you liked the last video, I'll have more videos coming and more frequently. I also be posting other scientific videos; eclipses, obtaining certain elements/chemicals by chemically extracting them from things, rocketry, physics, etc, if that's your kind of thing

Edit: Here's the balanced equation for the reaction if anyone is interested:

5C12H22O11 + 48KNO3 --> 24K2CO3 + 36CO2 + 55H2O + 24N2

This post was edited on 7/24/17 at 10:27 am