I want to create a multistage sugar rocket that uses multiple rocket engines at one time. My general idea is to have one main engine and 4 first stage engines that once burned decouples from the rocket by burning the connection between it and the main thrusters. I also want to keep it cheap so I do not want to buy electronic decouplers. So the rocket launches by activating the 4 rockets on the side decouples them then activates the last rocket and make so all parts are parachuted once out of fuel. I also do not know how to track the rockets to ensure I can find them again and reuse them without spending a lot of money. Any ideas? By the way this is not a school project, I just want to do it for fun and to learn a bit more about rockets. I also know about the fuel I could use already. Here is a link to another rocket I plan on copying and modifying for this project: https://www.youtube.com/watch?v=12fR9neVnS8
I suggest doing research and knowing what is legal for your area. Not to be a party pooper, but just so you don’t blow yourself up
Always a good goal. I’m 28 and still have all my fingers and toes!
As someone who played around with a lot of ESTES rockets as a kid, I’ve been wanting to try making a sugar rocket ever since seeing that video.
The biggest issue I think you’re going to have with what you’re trying to do is getting any rockets you have running simultaneously to burn at the same rate and for the same amount of time. If one engine dies before the others (even if it’s only by less than a second) or if the engines don’t have the same thrust, it will likely cause the rocket to pitch or spin which can create other hazards (such as a rocket coming back at you). Generally speaking this is why most model rockets will only use a single rocket engine per stage (and use progressively smaller engines for each subsequent stage).
In an ideal scenario where all the engines burn at the same rate, you could arrange 3 of them in a triangle configuration and one directly under your second stage engine. When the center engine burns out, the ejection charge (with no delay charge) should activate the second stage, and if you connect the first and second stages in a way that it can break-away (this may require some trial and error), the force of the second stage will jettison the first stage. Parachutes can be deployed from the outer 3 second stage motors (use a long delay charge).
Firing all 4 first stage rockets at the same time can be accomplished by wiring all of the starters in series, though this requires a larger power supply than the standard model rocket launch remote (which are underpowered as it is).
For tracking, generally the preferred method is to use brightly colored parachutes or streamers to visually follow the rocket as it falls. Ideally a long delay charge is preferable for the second stage (this charge itself should emit smoke which should also help with visual tracking) so that the parachute deploys as late as possible and isn’t carried as far by the wind. If you plan to fire at longer ranges, you might be able to find a small low cost GPS or radio transmitter that could be carried as a second stage payload (be sure to protect it from the ejection charge)
As far as legality goes, the FAA has specific regulations regarding model rockets. Your standard store-bought rocket motors do not require any special FAA authorization, but rockets that are higher powered or reach certain altitudes may require FAA notification/permission to launch. Normally any single A-D class (or equivalent) engines are ok when used alone, but for using two stages with a total of 5 engines you may want to look into the rules more unless the engines you use are all VERY low power (A-Class equivalent). Local municipalities may also have ordinances regarding model rocket launches (especially if you’re doing it from a park), however launching from an adequately large private property (like if you have a farm field) should not be an issue in most cases.
EDIT: After a bit of searching, Rockets under 125g propellant and 1500g liftoff mass are except from FAA regulations (rockets not in this category require a free waiver from an FAA office), this means you could use up to 5 D-Class rocket engines (<25g of propellant each).
How a 2-Stage Rocket Works
Model Rocket Motor Classifications
ESTES Rocket Motor Spec Comparison Chart
Thanks for the info and I plan on making this mainly as a proof of concept so Ill probably use very low power rockets and I have researched the laws a bit and one of my friends owns a farm with a large area they launch fireworks from so I will probably use that for launch or some where farther away. Also since I have very sensitive eyes to light I will use engines that will keep the rockets relatively low so I can see where it goes. For the first test I am thinking I will set up the rocket under a metal plate and secure it to something so I can test how much force it produces and to practice the timing so when I actually launch I will know how well it should work.