Amateur rocketry
DISCLAIMER: Anything you read on this page is being currently undertaken by me, has been made by me, or is being made by me. However, if you mess up, or take something wrong, you could get hurt. I AM NOT RESPONSIBLE FOR ANY OF YOUR ACTIONS HAVING ANYTHING TO DO WITH SOMETHING YOU LEARNED ON THIS PAGE. This page is for the legal construction, and use, of model rockets, nothing more. Rockets, seeing as though they burn at thousands of degrees farenheit are inherently DANGEROUS, if you don't know what you are doing, don't do it.

Intro to amateur rocketry
How to build solid rocket engines
How to make a cheap test stand
How to build a rocket (the vehicle)
Jonny Dyer's page on ignitor construction
An easily built, cheap deployment timer
A cheap liquid rocket motor from plumbing parts*
A cheap hybrid rocket motor also from plumbing*
*The liquid rocket is a couple of months from being finished (finally!) and the hybrid motor is a little farther off than that

Amateur rocketry, to me is the hobby of flying model rockets, or miniature aerospace models, that have a home-made motor, and are either built from scratch, or from parts given by suppliers (like Estes). For most average payed adults, or, like me, interested but limited funded kids, the only motors within the remotest possibility of making are the solid rocket engine, the hybrid rocket engine, and the liquid rocket engine. In this page I will talk a little on how to ignite, make, and fuel these with the hardest to find item needed is a hand held drill, but a drill press is preferred. Feel free to ask me questions, I like to answer questions (not, how big will it blow up dude?). I'm trying to update this page here and there, but my liquid rocket engine has long periods of going nowhere fast. I'm also working on an interesting monopropellant engine, but that's another story.

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Solid rocket engines engines
For this you will need PVC cement, a 1/2 inch dowel, 1/4 inch dowel, a 12 degree conical rotaree rasp, 10 inches of 1 inch in diameter PVC pipe, 30 minute epoxy, a male reducing coupler (from 1 inch to 1/2 inch), one section of CP technologies liner tubing, Phase stabilized ammonium nitrate (PSAN-I) (available from CP technologies), magnesium (available from Firefox, here), R-45HT (from CP technologies), N-3200 curative (CP technologies), a triple beam balance, Vaseline™, Rustoleum appliance white epoxy spray paint, and gray floor leveler. This will cost you about 40 dollars for eight motors, or so. First, take the 1/4 inch dowel, and cover the end up for about 4 inches in Vaseline™. Mix the floor leveler, and pour it into the male reducing coupler, reduced end down, until it is filled 1/2 inch from the top. Push the bottom of the 1/4 inch dowel through the center of the mixture, and let dry. Take the 1/2 inch dowel, and give it several thick coats of epoxy spray paint to cover up the pores in the wood. Then mix 60% PSAN (phase stabilized ammonium nitrate) with 20% R-45HT and 20% magnesium powder. Add in 11.1% N-3200 curative (by weight compared to the R-45HT, not the whole mix). The total propellant weight will be 94 grams, meaning 56 grams of PSAN, 18.8 grams of R45, 18.8 grams of magnesium, 2.1 grams of N3200. Mix thoroughly. You need the CP technologies phenolic liner tubing ( CP Tech) for this step. You will cut it to 9 1/4" length, and place the liner inside of the pipe. Then put the mixed fuel into the liner section. Push the 1/2 inch dowel (fully coated with Vaseline™) down the middle of the mixture in the liner. Put in a 80° F environment, and let sit for 24 hours. Grasp the 1/2" rod firmly, and pull out of the propellant by twisting it and pulling it out at the same time. Let the propellant grain sit for several more days. Then glue on the male reducing coupler with the floor leveler and the hole through it (your primitive nozzle) to the bottom end of the PVC pipe (the end with the now hardened fuel up to the edge). Use the 12 degree conical rotary rasp from your local hardware store, and use this to bore an exit section into the putty. Put wax paper (sorry, I forgot to mention this) into the opposite end of the pipe so that it fully protects the fuel. Do not let it cover the walls of the pipe, just the end of the propellant. Pour mixed epoxy (3/4 inch, make a full seal) over this. The epoxy will get very hot, but shouldn't ignite the propellant if you use 30 minute epoxy. The 5 minute type may ignite the motor, and it's not my fault if you use it or the 30 minute and start a fire. The epoxy can also burn you, so be careful. You might want to glue a 1" cap over the end of the motor to help hold the pressure and make it fit the CP Tech body tube (explained later) better. This motor will destroy an Estes kit, don't complain to me if you try it. Congratulations, you have made an engine worthy of full "G" power! It's exact specs are the following: 94 grams of propellant, 2.5 second burn time, 16 pounds of average thrust, 23 pounds of maximum thrust, 312 psi maximum pressure.

To ignite the motor, look in your local hobby shop for lazerfire or similar igniters meant to ignite composite propellant rocket motors. You will probably have to use 24 gauge speaker wire from Radio Shack to extend the igniter enough to let the top of the igniter be at the top end of the motor (very important, the end of the igniter MUST touch the top of the motor). That means about a 4" extension for lazerfires. To do this, cut a 4" piece of wire, strip the ends of both wires, and wrap one of the two sides of exposed wire around each of the two exposed lead wires on the lazerfire. You will need to get a car batter, 50 Ft of wire 18+ gauge wire, a door bell button, two jumper cable clips and two large paper clips to make an ignition system. One end of the wire is stripped, and the jumper cable clips are crimped on one side of the expose wire each. The other end of the wire is stripped, and each side of the wire is wrapped around one paper clip per side. Then cut the wire at 4 ft from the jumper cable clips. The end of the wire leading from the clips is stripped and so is the end going to the paper clips. One side of the cable clip wire is attached to one of the two terminals on the bottom of the door bell button. One side of the paper clip wire is attached to the other terminal on the button. The two loose sides of the wires are fastened to eachother. All of these connections should be soldered, but don't have to be. To ignit the motor, the igniter is slid into the nozzle and all of the way up the grain until it stops. Use tape or something to secure the igniter so the head of it stays at the top of the motor. Clip one paper clip to both leads of the igniter. Back off 50 ft unrolling the wire as you go. Clip one of the jumper cable clips to the positive battery terminal, clip the other cable onto the negative terminal (it doesn't matter which goes where). I must warn you that the voltage in the batter can REALLY hurt if you touch one or both terminals DO NOT TOUCH THEM. All that's left is to press the door bell button. This allows the current to short out the wire in the igniter, causing the igniter to fire and (hopefully) to ignite. If it doesn't ignite contact me here for help.

Of course you need a test stand or rocket to fire the motor in. Farther down on the web page I explain how to build a test stand. For a rocket (the best way to do it) you will need to get the body tube from CP tech that they say will fit the 1" motor and the nose cone which fits that body tube. My 1" motor will need some tape wrapping at the epoxy filled end to allow this end to fit the tube correctly. You will know how much when you get the tube. Anyway, you also should order there fin material. Then cut a fin 3 inches wide by 4 inches long in a rectangular form out of this fin material (you can change the shape, but don't change the size much, or the rocket won't fly straight and can be dangerous). You need three fins. Epoxy the 4" long side to the body tube at the bottom end (if it's not even with the bottom, it won't fly straight) and then epoxy the other two fins 120 degrees or as close as you can eye it to evenly spaced appart. Make sure they're straight. Put the nose cone in the other end of the tube, and load the motor into the bottom of the tube. If you want to get the rocket back in one piece, you need to buy an ejection timer (look one up here) from blacksky or the like. Then you need to follow its instructions to set it up and give hook it up to an ejection charge. I can help you here also. You will also need to put elastic shock cord and a parachute into the rocket. Screw an eye hook into the base of the nose cone, and tie one end of the elastic cord (7ft long) into it. Epoxy the other end of the cord into the body tube, or maybe use PVC cement to fix it. Tie four strings around the bottom edge of a trash bag, evenly spaced, and tie the strings into the eye hook. Glue a plastic straw to the tube so it's parallel with the tube and isn't directly in front of a fin. Arm the timer and ejection charge (these can be loosely fastened into the tube below the parachute, but MUST be fastened). Put some roof insulation (gray fluffy stuff) between the ejection charge and the timer, and also between the ejection charge and parachute. Neatly pack the parachute and shock cord into the rocket. Put the nose cone back into the end. Load the engine. Put the rocket on the launch pad by sliding the 1/4" rod through the straw. Make sure the rocket is pointing straight up. Launch the rocket by igniting the engine (see above).

You can also get aluminum and ammonium perchlorate from firefox, and make a more powerful engine. The mixture is 72% ammonium perchlorate, 10% aluminum, 18% R-45HT, and curative. You will have to make the nozzle opening with a 3/8" dowel for the motor if you use this formulation. You will also need to get an FAA waiver to fly a rocket with this fuel, so contact your local FAA office for instructions. Otherwise everything is the same. These mixtures are NOT set in stone, and I would advise cautious experimentation.

A 10 foot (maybe more) rocket built by John Wickman flying with a home-built PSAN and magnesium and R-45HT rocket engine. It was about an "L" engine, and the rocket soared to 2600 feet, or so.

A rocket engine built by me with the above PSAN/magnesium/R-45HT formula burning in a home built stand. This test was conducted for my 8th grade science fair project, and ended up getting me first place out of 150 students at the regional Western Colorado Science and Engineering Fair, and fourth place in my division at the state Colorado Science and Engineering Fair. This rocket used 45 grams of propellant, but probably qualified a "G" motor.

A PVC motor going off. Note the jets of flame shooting off to the sides, this shows the power of the engine. This also used 45 grams of propellant.
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The Stand

You can make a stand fairly simply. I didn't choose to make one with all the bells and whistles normally seen, but rather a $15-20 stand. It is made of wood, and if you face one of the closed sides toward yourself, you won't get hurt in an explosion. In fact two of my KN-sucrose propellants (not the above, much safer propellants) exploded, and I have all fingers, toes, and skin (no burns)! Anyway here's how it works.

First you take a two 24X8X1 inch boards, and lie them flat. Then you take four pieces 4X8X1, and cut a right triangle into the middle of one side, so that the sides are 45° to the outer side, and the last side is cut, the sides of the triangle should be about an inch long. Then you cut up from the bottom two inches from the side to two inches from the from. Cut in from the side, and you are left with two 1/2 inch pieces jutting out to either side. Next, do the same to the other boards. Then take them, and nail them to the boards 12 inches from the bottom for the lowest one, and six inches apart. Only nail two on each board. Then line them up so that the shelve like pieces on each of the two back pieces line up. Drill a hole through both 1/2 inch pieces, make sure to drill horizontally inwards so you drill from one back piece towards the other. Then take four bolts, and slide them through the four holes. Put the engine into the diamonds formed by the two triangle cuts, and using four nuts, tighten the stand down so it holds the engine. You can use bunjee cords to fasten the stand onto the ground better.

To test the propellants, and actually get readings, you may put a scale under the engine, and then burn it. Coat the scale with gray floor leveler to inhibit melting. The scale will be depressed (it might underscore actual pressure, but you can still compare different engines). I suggest you video tape the scale read-outs so that they can be reviewed. You might have to cut a viewing hole in the stand for some scales.

Liquid fuel rockets

Due to safety reasons, I won't post the plans for my liquid rocket engine until I have tested it. It is being made right now. It will cost you about $60, be fully reusable, cost about $6 a flight, and be about (I haven't tested it yet) an "H" or "I" engine. It will weigh a pound, and take 12 hours of work or so. The biggest thing that you will need is a drill press with a 5/8 inch metal bit. You can probably find someone with the drill, and buy the bit. Check back later for photos, and plans!
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The Timer

This was sort of custom designed for me by Bob Dyer in his great generosity (my thanks goes to him). His web page can be found here (don't pester him with your questions, ask me, he didn't ask for any questions). The schematic plan is below.

I have neither built nor tested this, and if you do build it, I am not liable for any property, personal or other damage it may do. Do three tests at least using a LED in place of an electric match, timing how long from the time of arming to light up it takes. You can use two AAA batteries to power it, together they meet the 3V noted by the battery symbols on the schematic. The main problem with this is that once you arm the last switch, 10, 15, or 22 seconds later the electric match will ignite. That means that the longer you take to launch, the less time. It is NOT armed on lift-off. In the event of a no-go, be careful, you must make something yourself to stop the timer if need be! You can E-mail me for help on construction, use, how to modify the delay settings, and on how to select the delay.

Hybrids

Again, not tested. Check later for plans and pictures. Should be similar in cost, materials (a little less), tools, and power to the liquid rocket. Just as reusable.