Homemade sugar kno3 rocket engines using used shotgun shell casings and simple a simple building procedure.
Due to a sort of unexpected demand for the tutorial video I promised (but failed to deliver so far) here is step by step instructions how they are made. I will post a video asap however I am currently not home and have no supplies to make video with. I should have it up in several weeks, depending when I come home from college.
INSTRUCTIONS:
1) Find all the supplies you will need a) Potassium Nitrate (aka Stump Remover, KNO3 ect.), this can be found at garden supply stores or home depot and lowes. b) Powdered Sugar c) Spent shotgun shell casings. If you know anyone that shoots ask them to bring you back some next time or drive to your local shooting range and ask if they have any casings you can have. They are usually more than happy to help you. d) A strong tape (fiber glass reinforced packaging tape, duct tape or similar. e) Packing and ramming supplies (Wood dowel rod in the diameter of the shell casings, rubber mallet, a wooden board and a nail a little shorter than the length of your empty shells.
2) Prepare your tools You will need to drill a hole in the end of the dowel rod for your nail to fit into. This will be your packing tamp. You may want to sand the tamp so that it slides inside the shells a little easier. Next you'll want to get the nail into the board so that it sticks out on the other side and the shotgun shell will fit nicely onto it.
3) Prep the shotgun shell casings. You will need to pop out the primer cap (the bit that ignites the gunpowder when the hammer strikes the shell). You may have difficulty doing this as it is necessary that you do it from the inside of the shell as opposed to the outside. You may want to find a nail or stiff wire longer than the shell to help you pop it out. This hole will the the rocket nozzle.
4) Mix your chemicals. It is necessary to mill your chemicals if you have not already done so. Most KNO3 is sold as a salt and this will not do, it must be a powder. It is a standard 60:40 mix of KNO3 to Sugar, you can use more KNO3 for a faster burning propellent but be careful not to exceed the limitations of the casing. Use caution when experimenting with the ratios.
5) Insert the casing onto the nail nozzle first and start slowly packing the propellent. After each tablespoon of propellent insert the tamp into the casing and pack it (be careful to not hit too hard because the casing will blister at the bottom under the pressure.)
6) Once the propellent is fully packed shove a tissue into the end and pack that in. Next pour epoxy (or hot glue for the lazier hobbyists, don't worry it wont fast enough in flight for it to cause the engines to fail). NOTICE these engines will not eject a parachute. I have made these to eject after a time delay but I'll let you guys google a method to do that. First focus on getting them to fly.
7) Next you need to pull the packed engine off the nail. This may be harder than it sound. The packed propellent grabs onto the nail just like wood does when you nail something together. Using a chisel to pry it off the board seemed to be the simplest method for me.
8) Lastly you must wrap the casing in a fair amount of tape. Using some sort of reinforced tape is best because the tape basically becomes the casing in flight. Shotgun shells made out of plastic will melt fast and cause your engines to fail mid-flight. Tape is the best solution.
9) Next you can either modify a light rocket (so it doesn't break when it tumbles back) or attach a stick to the engine and fly it like a firework. When using the stick method you must make sure it is balanced. When you hold the rocket on your finger it should balance right below the nozzle. if the stick heavy the rocket will still fly (but thats just unnecessary weight) but if the stick is too light the rocket will spin out of control and be rather disappointing.
10) Prime your rockets with fuses. You may want to prime the core of the engine with black powder and use cannon fuse to light it. Plug the nozzle with tissue or hot glue. Be very careful with black powder as it can ignite without warning if you're being reckless (and it burns FAST). Black powder isn't necessary but it ignites the core more evenly and thus makes a better engine. If you choose to just use cannon fuse inside the core to ignite it the rocket will have a slower more dramatic take off because the core will take a few seconds to fully ignite and build thrust.
I hope this is helpful to those interested in using shell casings for rocket engines. I will post a video as soon as I can that shows the process in a more organized, detailed manner. But as I said, I won't be home for a while and won't be able to make the video till then.
Homemade fuse tutorial http://www.youtube.com/watch?v=TAqYLBSJgwI&feature=related
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what size of dowel rod did u use? and did u use 20 or 12 ga shells?
Kedolomer 1 year ago
@Kedolomer The size isn't anything special so long it fits pretty snugly into the shell; for this I think it was a 5/8's inch dowel. I used 12 gauge shells but you can use any size. IMO the bigger the better which in this case would be 12 gauge shells.
fortnightproductions 1 year ago 3
how come the second one worked and the first one didnt?
please reply
WebShareMusic 1 year ago
@WebShareMusic I think that was the one I tried making with a black powder based propellent instead of the sugar and I didn't quite have the finalizing the casing down (wrapping them in tape), so the propellent ended up melting through the shell and going KATO shortly after it was lit.
fortnightproductions 1 year ago
@fortnightproductions I lied the one that KATOed was a different one. The first one that never got off the ground had a mix of baking soda to slow down the burn however it had too much so it was essentially a giant smoke bomb. From my experience I found baking soda is pretty much unnecessary but some guys will tell you it helps the propellent burn smoother. Experiment and decide for yourself.
fortnightproductions 1 year ago
ok thanks, can you do the step by step .cool
27simber 1 year ago
@27simber I just updated the description. If you have some experience with homemade engines it should be easy to follow. If you have any questions feel free to PM me.
fortnightproductions 1 year ago