BigBang Posted May 20, 2006 Posted May 20, 2006 Watch out for micrograins, they are inherently dangerous. Many a person have been killed working with these, and the bigger they are, the more risk is involved. They do make for some amazing pics though http://www.rrs.org/Projects/Launches/launches.html bottom left
chappers Posted May 20, 2006 Posted May 20, 2006 ,May 17 2006, 07:13 AM] Hmm, if your using a rocket with a nozzle, wouldnt it CATO if you run a fuse in to the hole in to the propellent? so long as the convergant part of your nozzel is ok the igniter will be spat out the end no problem, not had any problems in that department with drinking straw, black powder igniters.
d4j0n Posted June 21, 2006 Posted June 21, 2006 Is it okay to use old teflite sugar rocket comp even after it's gone majorly clumpy?
ActionTekJackson Posted June 21, 2006 Posted June 21, 2006 Woot, one of my KNO3/Sugar Rockets. 3/4" ID at 3 1/2" long. half cored. 3/4"ID KNO3/Sugar Rocket As you can see it wasn't balanced quite right. A friend and I worked on this and they fly flawlessly straight now :-)
aquaman Posted June 21, 2006 Posted June 21, 2006 Nice rocket. It did kind of go off to the side but it went pretty high. So over all it was a good rocket. Also I like the video's quality, it is so clear. What camera did you use?
justanotherpyro Posted June 21, 2006 Posted June 21, 2006 We used my Cannon Powershot A-540, and the video was taken at 30 fps. We really need to catch the next one with the 60 FPS feature
ActionTekJackson Posted June 21, 2006 Posted June 21, 2006 We used my Cannon Powershot A-540, and the video was taken at 30 fps. We really need to catch the next one with the 60 FPS feature It gets better?!?! *drools* Tomorrow man.... whistle rocket....
_DB_ Posted June 24, 2006 Posted June 24, 2006 Has anybody ever had an accidental ignition while making RCandy? From reading on James Yawn's site it looks like a nice and safe fuel when made properly. But the only place I could make it is in my kitchen oven. I'm not too keen with the ideal of making it in my house though. I think it could be safely done if kept at the right temperature, but I don't know.....
weknowpyro Posted June 24, 2006 Posted June 24, 2006 Yea i have had this stuff egnite before while cooking it but if you make sure its not smoking you will be ok.
weknowpyro Posted June 24, 2006 Posted June 24, 2006 No i was cooking it over a bunsen which was on a saftey flame.
_DB_ Posted June 24, 2006 Posted June 24, 2006 I think making it in an oven is the safest route, since you can completely contol the temperature and all.
Pyrohawk Posted June 25, 2006 Posted June 25, 2006 I make RCandy all the time Po. It works very cicely and I've never had it ignite. Then again I use a Toaster Oven though.... so it wouldn't matter to much if it did ignite. Try the making RCandy in a pan method, its on Yawn's site....the product seems just as good and won't require an oven. But then again your back to a skillet or pan... I like the stuff because its like a putty that can be molded and stuff!!! Very neat.....
_DB_ Posted June 25, 2006 Posted June 25, 2006 Po? Anyway, I was considering buying a cheap toaster oven so I could make it outside. Just incase it was to ignite. It seems like the chances of it igniting are rather low if made correctly, but I'd rather not take a chance.
Pyrohawk Posted June 27, 2006 Posted June 27, 2006 Hehehehe wow I'm crazy.... ya I meant _DB_ ... I kinda glanced at the name of the poster, saw two letters and figured it was Po.... I don't know considering Po is never around anymore! Hehehe I got my Toaster for 7 dollars in a second hand store!!
Deceitful_Frank Posted June 28, 2006 Posted June 28, 2006 Hi chaps, I am wanting to improve my small rocket candy motors and have a quiery concerning Kn ratios and how to calculate the IDEAL throat diameter for a rocket of given design and dimensions. I'm not asking to be spoonfed. I've researched rocketry and newtons laws to quite spme depth. I'm fairly profficient at math but differential calculus is where I must draw the line for the moment! Basically I'm familiar with different grain designs and their effects, calculating Kn ratios etc but I need help determing the INITIAL Kn ratio required to get the craft off the ground as I beleive that at takeoff, any propellent burning and not having the force to counteract the downward pull of gravity and accelerate the rocket upward would be wasted. IIRC This is how you design your nozzle... I'd be using an 80 gram candy (with or without Fe2O3) core burner bonded inside a strong 1" ID cardboard tube so it would act as its own casing on its progressive burn up into the sky. I think an initial upward acceleration of 2g would suffice to quickly gain stability on a suitable bamboo stick? What would happen when the propellant has burned to the casing and the cardboard receives the full working pressure... I'm not too concerned with at this time. Thanks in advance
gwx Posted July 2, 2006 Posted July 2, 2006 I made the propelalnt by melting kno3 and sugar pretty easily. put a beaker containing propellant over a saucepan and heat over low heat. dip a thermometer inside to tell the temperatures. dont let it go above 180 by adjusting the flame size. stir while it is heating. thermometer costs abt USD$3. quite cheap mercury in glass which reads till 360degC
Mumbles Posted July 2, 2006 Posted July 2, 2006 Yeah, about that. I HIGHLY HIGHLY suggest not using open flame. It may have worked up until now, but you will have an accident. From the proceedure you outline it seems you are close by and therefor will be at risk for some fairly bad burns.
justanotherpyro Posted July 2, 2006 Posted July 2, 2006 I made the propelalnt by melting kno3 and sugar pretty easily. put a beaker containing propellant over a saucepan and heat over low heat. dip a thermometer inside to tell the temperatures. dont let it go above 180 by adjusting the flame size. stir while it is heating. thermometer costs abt USD$3. quite cheap mercury in glass which reads till 360degC Where exactly? As far as I know they banned production of those thermometers, and the only way to get them is after market. I think they can still manufacture mercury filled lab grade thermometers, I'm not sure.
gwx Posted July 3, 2006 Posted July 3, 2006 Well I can only use a kitchen stove since a hotpan will bust my budget unfortunately. Wish I could get that. But by heating over a stove flame ( flames, since the flames form a circle ) I made the following precautions - ensure as little black areas as possible. in richard nakka's site these black areas means overheating. - try to stir as much as possible when the propellant has started melting - mix very low amounts of propellant. not more than about 80 grams at the same time. - ensure that the beaker sides are directly above the flame circle ( flames ) of the stove - place thermometer INSIDE the mixture and ensure that you place it near one of the flame areas - ensure stove flame is as high as possible from saucepan so that overheating does not occur at the points directly above flame. convection currents prevent uneven heat distribution. - stop heating as quickly as possible. I've done this around 5 times already. I use a small pyrex beaker each time. About the mercury-in-glass. they are old stock which I got from my chem supplier. unfortunately the calibration is slightly off. It reads steam point as 80 deg C. So I presume a reading of 150 on my thermometer means about 180 on a correctly calibrated thermometer. the nakka site states 200 though.
WV-Pyro Posted July 9, 2006 Posted July 9, 2006 I do not have any KNO3, so instead, I use KClO4. I know it is more expensive, but it is the only thing I have. I mix it in a 65:35 ratio, but I can never get them to take off. I am using a 1"ID x 4" tube with a rammed clay nozzle. I have tried many different nozzle and core sizes. I always make the core the same size as the nozzle, because I drill it. Thing is, they just always sit on the gorund and slowly build up steam until eventually they explode, finish burning, or blow out the nozzle. I am hand pressing these because I am not sure whether I can ram KClO4. Would it be safe if I rammed it? Also, would the ratio be any different than that used with KNO3? If so, can someone please tell me how to figure it out, or do it for me I have also tried adding 10% Sulfur to the mix, which didn't help at all. The KClO4 is from DiscountPyro and I am using powdered sugar. Thanks for any help.
_DB_ Posted July 9, 2006 Posted July 9, 2006 I would recommend getting some KNO3, and I don't think it's a very good ideal to ram any compositon containing KClO4. But if you must stick with the KClO4 you could press the mix with a hydraulic jack or something of the like. Better fuel compaction would probably result it better rockets. You might also try priming the core with some loose composition or BP.
Mumbles Posted July 9, 2006 Posted July 9, 2006 There are one of two things causing your problem. 1) You're using perchlorate2) Your ratio I'd suggest some different ratios to try to get better results. Two different oxidisers are not going to work the same in the same ratios.
WV-Pyro Posted July 9, 2006 Posted July 9, 2006 I have no idea as to what ratios to use. Is there any suggestions that could atleast get me started in the right direction with the ratio?
Mumbles Posted July 10, 2006 Posted July 10, 2006 I think you started at a good spot. I would try working in increments of 5%. I would try 40:60 30:70 50:50 20:70 first to see which one is best, if any improvement over the 35:65. It will tell you which way you need to go. You may want to use smaller tubes for the testing, say 1/2" ID just to save on materials before making bigger rockets like that.
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