How To Fuel Combustion Cannons & Diagnose Problems - NightHawkInLight

hello everyone welcome back in this video what I'd like to do is address an issue that many of you have commented about on my previous videos and that is how to create the proper fuel air mixture to fuel my combustion projects whether they be rocket launchers like this one or some of my cannons like my vortex cannon or the miniaturized can instead of made earlier now in these videos I use a variety of different fuels usually for the smaller projects I'll use rubbing alcohol as the fuel and for larger projects like say my vortex cannon I'll use an aerosol spray now there are different reasons why I would use each of these fuels and so that's what I'll be getting into in this video the upsides and downsides of each type of fuel and why I might choose them for the projects that I do I will be talking about three different types of fuels in this video and the most important aspect of each one is how they create a fuel air mixture that is at the proper ratio to facilitate combustion now most people assume that the more fuel you add to a combustion process the more powerful that combustion will be but that's absolutely not the case in a fuel air mixture if you add too much fuel there will not be enough oxygen for that fuel to burn and so it may not ignite at all and if it does ignite it will be much weaker than a lesser amount of fuel would have been so the first fuel I'll talk about is rubbing alcohol 91 percent like I mentioned before now this is the fuel I used when I first made the video about these bottle rocket launchers now inside of this design is the same launcher it's just in a little nicer looking housing so these launchers work by first fueling the bottle with some of this rubbing alcohol and shaking the alcohol inside now the way alcohol works as a fuel is it works through a process of evaporation evaporation is dependent on air pressure and temperature and assuming air pressure stays fairly consistent the concentration of alcohol that the air inside the chamber will absorb should remain the same no matter how large or small the chamber size is now this is excellent assume you have the proper air temperature to create a fuel-air ratio by evaporation that is in the combustible range for alcohol and around 70 degrees Fahrenheit this should produce a favorable result every time now some of the downsides of using alcohol is that since it's so temperature dependent if the weather changes and it becomes colder out or too hot out you will no longer be making the proper fuel-to-air ratio inside the bottle another downside of using a liquid fuel source is you run the risk of some liquid remaining in the bottle even after you've shaken the excess out now this is a danger because when the bottle fires it could create an overspray and the overspray could catch things near the launcher on fire if you watch this slow motion clip of a bottle firing using alcohol as fuel you will see a fine mist exit the mouth when the bottle fires this is excess alcohol spray and it can cause burns another issue with using the liquid fuel is that you would have this bottle presumably nearby now if this whole bottle were to catch fire when you launched a rocket and if it were to spill you might have a major fire on your hands so you do have to exercise a fair amount of caution when using liquid fuels you should always cap the bottle before firing the launcher and set the excess fuel a good distance away the next few I'll talk about is aerosol spray now this is the fuel that most people will use in potato guns and things of that nature and in fact I use this sort of spray in my vortex cannon that I built sometime I think last year what makes this sort of fuel combustible is the gas that they use to pressurize the cans usually butane or methane this gas partially dissolves into the liquid that's inside the can so when it's sprayed out into a fine aerosolized mist it bubbles out of this mist just like carbon dioxide bubbles in a carbonated soda since the fuel in this case is an actual gas that can displace the air inside your chamber and not simply evaporate into it you can very easily over fuel your cannons and it will not fire now determining how long to hold the spray is a process of trial and error for your chamber size first chamber size like this typically it would be around two and a half to three seconds the problem with aerosol spray really comes to light when you try using it with smaller cannons if the chamber is too small it can become impossible to press the spray down for a short enough time that you don't over fuel the chamber for example trying to fill a soda bottle with this spray to use in my soda bottle launchers would be extremely difficult because it would only require about that much time to over fuel the chamber now if you're having a lot of trouble finding the proper fuel ratio and you cannot get your device to fire at all a good way to test to see if your ratio is too rich or too poor in fuel is to ignite the chamber with it open if a chamber has been under fueled it will not ignite at all even when exposed to an open flame if it has been over fueled it will ignite but it will only burn at the opening where there is excess atmospheric air to interact with the fuel if the chamber is properly fueled the flame front should very quickly move from one end of the chamber to the other one final note about aerosol sprays is that most people will use hairspray or spray deodorant to fuel their cannons now I don't like these because they leave a sticky residue inside the chamber as an alternative I prefer to use anti-static spray which does not have these sticky ingredients and shouldn't gum up your cannon the final fueling option I'll be discussing in this video is a propane torch now this is an excellent option for many different projects because by its very nature a propane torch injects the exact amount of air along with the propane that that propane needs to burn you can see it creates a very hot flame and it can only do that because of these ported air holes at the bottom of the stem as propane is injected into the nozzle it carries along air with it which is in the precise mixture needed to best facilitate combustion now I've used this same torch to fuel my propane popgun project and that works by injecting the propane and air mixture into a large vinyl tube like this now you can use the same method to simply inject propane directly into the chain of any other combustion project the reasons why you might not choose this option is first of all a torch like this can run about fifty dollars so it's quite an expensive option and it can also take quite a while to fill a large chambered cannon out of a small nozzle it's great for soda bottle rockets however and it can also work well for smaller cannons though it may not work well for the very smallest cannons like my lighter mini cannon for the simple reason that the nozzle will not fit inside the chamber before I close out this video I'd like to suggest that you go check out the channel Cody's lab now I've recommended Cody's videos before on my channel and that's because more often than not his videos fall right in line with my own interests in this case his latest video tests if muzzle velocity is affected by a cannons recoil so go check out that video I think you'll really enjoy it if you are one of my patreon supporters first of all thank you very much for supporting my videos and I also want to let you know that I will not be charging you for this video since I didn't actually build an original project I will usually not charge my patrons for videos like this one if you enjoy my videos and you're not yet one of my supporters on patreon please check out my page in the video description below I could really use your support in any case I hope you enjoyed this video and I hope you find it useful thank you for watching

Channel: NightHawkInLight

Views: 110,780

Rating: 4.940732 out of 5

Keywords: How To, DIY, Cannon, NightHawkInLight, Rocket, Potato Gun, Spud Gun

Id: UKS2DNl_AgI

Length: 7min 59sec (479 seconds)

Published: Wed Oct 12 2016