Considering building a Sugar/KN03 Rocket - Quick Question

[brandonman]

Hello. I'm considering building a KN03/Sugar rocket some time in the near future. I have been watching quite a bit of videos, and reading up, and I would like opinions on this process I found. It involves removing the propellant *before* it gets to dry (Unlike most I've seen) so it is a bit gloopier. I guess this helps with cracking and such? I am poor at explaining it, so here is the video, which will probably explain it much better than I can. (4th Video out of 5 he has currently done. ) Let me know if you would trust this to be an effective method, or if I should go with the traditional method to make it solid.

 

[RisingFury]

There are two good way you can do it.

The first is to cook the fuel and then just pour it into the engine.

The second one is that you take a coffee grinder and grind your sugar and KNO3 to powder, individually at first and then put them together in the grinder and grind again. That will ensure the particles mix. Do not shake the mix - that will make the large particles float to the top and small to the bottom. Sugar is usually larger. Once you're done grinding your fuel, you can then put it into the engine. Keep in mind, there's a lot of air in the mix, so you can use something to push it into the engine and pack it tighter.

If you do the second approach, make sure to tightly pack each layer. That will ensure that the structure doesn't crumble once you light the engine.

 

[agentgonzo]

Don't make it over a gas stove. That's by far the easiest way to lose your eyebrows

 

[Brycesv1]

friend of mine a while back was making a smoke bomb. its basically the exact same thing without the corn syrup so it turns into a peanut buttery mixture. he cooked it too long and it flashed over. lost his arm hair, his eyeborws, lashes, and most of his bangs

 

[insanity]

I am building some and the plan has been to cook and pour into each of the tubes. So far nozzle size and ignition system have actually been the biggest problems.

 

[Brycesv1]

i dont know of it would work reliably for multi engine rockets but in the past iv just taken wires and stripped the ends, stuck it into the fuel and connected them to a 9 or 12 volt battery. the heat at the ends is usually enough for ignition

 

[RisingFury]

You can also buy RC glow plugs:

These things are used to ignite the fuel in nitro engines. They need 1.5 V and they glow yellow/red, depending on which ones you get.

 

[insanity]

Good suggestion. The current setup is that there is a simple circuit with 8AAs (for 12V), on/off safety switch, a 12v red LED, and momentary on push button, and the coil and spark plug out of VW bug.

We're getting the required voltage and current into the coil, but it is not firing the spark yet. If this doesn't work, I'm opting for the current electronic ignition rigged up with some nichrome wire and a fuse.

 

[RisingFury]

Ok, here's how you create a spark:

You make a coil with large inductance. Large amount of turns, large surface area, small length and a ferromagnetic core - a nail or anything else made out of iron.

You then pass a current through the coil. The coil stores energy when it builds a magnetic field. Then you disconnect the switch and the coil will instantly release the energy. You'll notice a spark at the switch. The larger the current before you turn off the switch, the more energy you'll have for the spark. The shorter the wire, the lower the resistance and thus the higher the voltage.

 

[Brycesv1]

ill have to remember that. my method has a failure rate that really would be considered unacceptable. though it does always work eventually

 

[RisingFury]

I'm gonna write you a diagram and do some math for you and scan it, either today or in the next few days.

If you're a DIY guy, you're gonna love it

 

[Artlav]

The second one is that you take a coffee grinder and grind your sugar and KNO3 to powder, individually at first and then put them together in the grinder and grind again.

Put them together in a grinder? How sure are you that it won't ignite, encrusting your face with pieces of the lid?

 

[Brycesv1]

Put them together in a grinder? How sure are you that it won't ignite, encrusting your face with pieces of the lid?

reminds me of scarface from "the punisher - warzone"

 

[Ghostrider]

The second one is that you take a coffee grinder and grind your sugar and KNO3 to powder, individually at first and then put them together in the grinder and grind again.

I'd rather use a wooden mortar for this kind of deal.

 

[Ark]

I can offer this small piece of advice: When it comes time to ignite the fuel in the engine, DON'T fill the open space in the middle of the fuel with gunpowder, stick a fuse in, and tape it over. That makes a pipe bomb.

 

[RisingFury]

I'd rather use a wooden mortar for this kind of deal.

Tried that myself, but a coffee grinder produced smaller particles and resulted in better burn.

 

[insanity]

Good advice, although it sounds like it comes from experience.

When I was in high school I had some friends who made simple explosives to detonate in an abandoned quarry. One day the cops showed up and they got brought up on some pretty serious charges (which were lessened with mandatory community service). The lesson: When working with explosives, any possible reason for a good time to be seen as terrorism it probably will be.

 

[Ark]

Good advice, although it sounds like it comes from experience.

Oh yeah. I built a pair of PVC rocket engines when I was a teenager, used KNO3 and sucrose or something (wasn't sugar) for the fuel. The first one I had problems getting to light, so I just rammed some gunpowder in it and it blew bits of PVC all over the field. The second one lit successfully, but I guess the fuel had been sitting around so long it couldn't develop the thrust to get the thing off the ground.

 

[Brycesv1]

The second one lit successfully, but I guess the fuel had been sitting around so long it couldn't develop the thrust to get the thing off the ground.

Sounds like you forgot to open the hover doors:lol:

 

[Ghostrider]

The lesson: When working with explosives, any possible reason for a good time to be seen as terrorism it probably will be.

These times, anything can be viewed as terr-ow-rism.