DIYMark Posted June 6, 2008 Posted June 6, 2008 Thank you for those dimensions. Today I shot a KNSU rocket with a report (BP) and prior to launch I made a few tests. First the nozzle blew. Second I shortened the core,; the back plug blew. Third I shortened the core and still the plug blew. Finally I scratched the inside of the PVC where the nozzle/plug were and tried that. It worked! The rocket went up really quick! and my delay was spot on! After teh smoke trail stopped a fraction a a second I saw confetti raining dwon followed by a boom. Probably +150 meters up which is pretty good All this was done on dry mix while I waited for your replies Also I tried and "Rcandy" header. The plan was to use R Candy as stars to make trails of smoke as they flew out...but It didn't work! Either the Rcandy stars were already gone from the burst, or the burst was too fast to ignite the Rcandy. Oh well. Oh and good luck on your next project Sound like fun. Also is the core ID of the bates grain in your dimensions the same as your nozzle?
Deceitful_Frank Posted June 6, 2008 Posted June 6, 2008 Just a quick one before I go out... Your nozzle throat must NEVER be larger than the core ID or the flow of gases down the core will cause erosive burning and strip the core of material, wasting fuel and causing possible CATO. 'til now I've used an 8mm clay throat but for my next project it will be a stack of three M8 steel penny washers 8.4mm ID for a max Kn of 305 and a 120 gram grain.
DIYMark Posted June 6, 2008 Posted June 6, 2008 Thanks for the hint - I never knew what would happen Sounds like your motor will be a real power house!
Yankie Posted June 21, 2008 Posted June 21, 2008 I have made 3 20mm by 100mm rockets and all have blown the plugs out, the first one had a small nozzle, the second one had pooply rammed end plugs, the third one had a bigger nozzle and the inside of the tube had a groove so the end plugs wouldnt come out. yet it stiil failed. should i make my fuel slower or my nozzle bigger? I'm using 20:11 KNO3:SU
Flying dutchman Posted July 29, 2008 Posted July 29, 2008 Hello,im new in making rcandy rockets,but my first rocket works well i think.I use recristallised rcandy,63/37 ratio,with 1% Fe2O3.I crush my rcandy to fine powder with a screen,then rame it into a cardboard tube,with a kitty litter nozzle and without a core.My rcandy: http://www.youtube.com/watch?v=oEVoXbtbs9cThe rocket: http://www.youtube.com/watch?v=DJ7VJ8gVyqo
TheSidewinder Posted July 29, 2008 Posted July 29, 2008 Nice burn test! Your rocket needs a longer stick, though. From the video I can't be sure, but it looks about half the length it should be. Did anyone get chased?
Flying dutchman Posted July 29, 2008 Posted July 29, 2008 Thank you.Yes,i know,the carboard tube was about 7cm lengh,and the stick was maybe 15cm.Nobody was cheased but the rocket land just at the forward of a pharmacy door
oskarchem Posted July 29, 2008 Posted July 29, 2008 Or maybe the nozzle was drilled off-center? Because my sticks are 2x as long as the tube. And they fly fine.
Flying dutchman Posted July 29, 2008 Posted July 29, 2008 Or maybe the nozzle was drilled off-center? Because my sticks are 2x as long as the tube. And they fly fine.Yes,i thinks it's that,and i don't use a drill tool but i only make a hole in the kitty plug with a nail.
Flying dutchman Posted August 4, 2008 Posted August 4, 2008 Hi,so I don't have acces to karo syrup,so i tried another sugar's.I've tried this ratio:65g KNO320g Sugar15g glucose1g Iron oxide (III) I think the burn rate is higher,than with only table sugar,what do you think ?Here is the video: http://fr.youtube.com/watch?v=iOdg_SBhdIY
Flying dutchman Posted August 9, 2008 Posted August 9, 2008 So i don't know how I can edit my posts,so i make a new:In the precedent post,the rcandy was not perfectly dry at all,so the burn rate was pretty slow.Here a video with a perfectly dry rcandy,the burn rate is much higher.http://fr.youtube.com/watch?v=xPRiuObpMQ4If a light on a small amount,it fly in the air like an helicopter,for about 3 meters!
TheSidewinder Posted August 9, 2008 Posted August 9, 2008 Just FYI, you have a fixed amount of time to edit your posts, after which you have to make a new one. If a post of yours REALLY needs editing, PM me and I can fix it. (But there has to be a compelling reason to do so.)
PyroCanada Posted August 16, 2008 Posted August 16, 2008 Anybody here tried ramming 65/35 KNSU propellant into a 1/4" x 2" casing?
PyroMan16 Posted August 15, 2009 Posted August 15, 2009 I've been trying to find the best formula for KNSU rockets for years, the best: (in my opinion) 65g. finely powdered KN0335g. finely powdered Sugar(Sucrose/table sugar)2.5g. Red Iron Oxide(Fe203) Mix the 3 chemicals well till you have a pink powder then on parchment paper mix the the dry powdered fuel with a mix of 50% alcohol and 50% water. Mix it well till it turns to a pink paste and spread it thin with a spatula(so it drys faster). Then lets it dry for a day or so and force the partially dried paste though a window screen. Let the fuel dry for another day or so and you should end up with a very fast burning fuel that performs better than just dry powder mix (which also works well) and almost comparable to Rcandy (Jimmy Yawn's method). It is also very easy to handle and pack (unlike airfloat powders and Rcandy. I have found that there are more CATOs thou so the nozzel and plug need to be made stronger or larger. There are better mixes, I know but this is cheap, easy and has a high success rate.
Twotails Posted August 15, 2009 Posted August 15, 2009 Honestly i find Potassium Chlorate and 10x powderd sugar works fine. Made a 10g test batch today, and seemed a little to reactive, i was trying to think of a way to reduce it to a usable level, maby 1-5% sodium bicarb? the formula i used was74.5% potassium chlorate25.5% sugari made a 10g batch, so i rounded it off to 75/25. it worked nicely when compacted(lightly) into a thick walled tube, im unsure of the ID but it was just over 1in long. i had it glued to a spoon( not on perpose, i couldent get it off) has anyone used a chlorate mixture before? I normaly stick to Black powder as a fuel.
TheEskimo Posted August 15, 2009 Posted August 15, 2009 From what I have read, KCLO3 and Su are not to be generally mixed. They can, apparently, be quite unstable together. Here's a piece by james Yawn, a well-recognized RCandy developer.http://www.jamesyawn.com/kclo3/notes.html
andyboy Posted August 15, 2009 Posted August 15, 2009 has anyone used a chlorate mixture before? I normaly stick to Black powder as a fuel. Klorex 55 mixed with sugar was one of the most common "bomb" mixtures when I grew up. In 1990 Klorex 55 was banned for sale because of the dangers of people using it, ramming KCLO3/Sugar is known to make it go of with a bang. I would strongly discourage it!
PyroMan16 Posted August 17, 2009 Posted August 17, 2009 I've never heard of Chlorate used in rocket comps.?
tombonge Posted January 20, 2010 Posted January 20, 2010 I wanted to make sugar rockets back in the early 90's when I was a kid, but could never find any KN03. Now with the internet its much easier to order the supplies you need so I am going to give it a try again. A few years ago I saw a site sellign sugar rocket starter kits, with chemicals, casings, instructions, everything you need, but I can't find it now. I have searched and found sites selling chemicals and supplies but I can't find any kits like the one I saw.
EEguy Posted January 20, 2010 Posted January 20, 2010 I wanted to make sugar rockets back in the early 90's when I was a kid, but could never find any KN03. Now with the internet its much easier to order the supplies you need so I am going to give it a try again. A few years ago I saw a site sellign sugar rocket starter kits, with chemicals, casings, instructions, everything you need, but I can't find it now. I have searched and found sites selling chemicals and supplies but I can't find any kits like the one I saw. It is not hard to make the tooling, you could do it yourself. NichroPulse offers some professional drawings for 3/4" I.D. core-burner sugar propellant motors on their website for a small fee. They are drawn to meet what a typical machine shop would need to see. You can tweak the dimensions with the machinist's help to fit different motor tubes. You could also build the tooling out of wood instead of aluminum. I recommend a hard wood like maple if you do. Check out this How To Make Clay Rocket Nozzles video for ideas. Also, check this site out:http://www.wolterpyrotools.com And take a look at Skylighter's part # TL1204 (www.skylighter.com) Hope this helps.
bbeck7 Posted January 26, 2010 Posted January 26, 2010 Substituting potassium perchlorate for the nitrate should increase the pressure exponent,n, for the propellant making it advantageous for an end burner but problematic for a core burner.
apcqazwsx Posted July 11, 2010 Posted July 11, 2010 Has anyone found a way to get a tail from these rockets without a metal? Such as with charcoal?
dagabu Posted July 24, 2010 Posted July 24, 2010 What kind of tail do you want? There is plenty of white smoke, are you looking for sparks? Add 10 coarse charcoal when still a liquid and try that. You will lose some thrust but you will have a tail. Be warned, the grain will not be as solid since the charcoal will fracture easier then the grain.
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