Rcandy

[firetech]

Anyone had any experience with rcandy? its great stuff. I'm currently prepping a 1'' motor for a 48" model rocket I made about a year ago. Topped out at about 96 lbs of thrust. The data was calculated not measured using KnCalc, a program designed by a fellow sugar rocketeer Jimmy Yawn. His website is www.jamesyawn.com. He has had great success with rcandy over the years and has done great things with it. I'll upload some pictures if anyone would like me to.

[Mumbles]

I believe this thread has some useful information on rcandy.

 

http://www.apcforum.net/forums/index.php?s...t=0&start=0

[Pyrohawk]

Yep...I love the stuff. Its so easy and nice to work with. A little more time consuming but worth it for the workability and boost in performance.

 

I've used it a decent amount and have yet to have an issue with it... I did a few experiments with it. I was emailing with Yawn and he said he wanted to try making fuel with Barium Nitrate and Strontium Nitrate and Sodium NItrate. But had no access to Strontium or Barium. So I tried it and let him know what I found. He's a great guy, very helpful and fun guy.

[firetech]

Hawk, I have had ongoing email discussion on similar topics discussing rcandy. He is a very bright man, quite interesting to talk to also. I'm sure the formulas with Sr and Ba had trouble because of solubility issues. He sure blows through a lot of KNO3 though! I hear he's been doing a lot for Sugar Shot to Space.

[derekroolz]

I am a complete noob to pyrotechnics, I have made a few fountains some were ok. I have tried multiple times with sugsr rockets...failed every time... what the hell are cored rockets and what do you use in the cores and what are your guys dimensions for your rockets: Nozzles height of the nozzles, size of the hole drilled in the nozzles, and i need to know the best mix for the rockets i have any type of sugar KNO3 and sulfer but am unable to get ahold of fe203 and titanium i can get al powder and magnesium powder but takes a long time to grind it down so HHHHHEELLLPPP!!!!! a fellow pyrotechnic

 

ps: when you say kno3/su do you mean kno3 to sucrose

 

you all will be incredibly helpful for your replies

[Seymour]

I am a complete noob to pyrotechnics, I have made a few fountains some were ok. I have tried multiple times with sugsr rockets...failed every time... what the hell are cored rockets and what do you use in the cores and what are your guys dimensions for your rockets: Nozzles height of the nozzles, size of the hole drilled in the nozzles, and i need to know the best mix for the rockets i have any type of sugar KNO3 and sulfer but am unable to get ahold of fe203 and titanium i can get al powder and magnesium powder but takes a long time to grind it down so HHHHHEELLLPPP!!!!! a fellow pyrotechnic

 

ps: when you say kno3/su do you mean kno3 to sucrose

 

you all will be incredibly helpful for your replies

 

Ok...

 

A core is a cavity through the centre of the motor which increases the surface area, and therefore the thrust. With KNSU (yes, that means Potassium nitrate/Sucrose) you will need a core to get a flight. Unless you have tooling which creates a core as you ram or press the fuel (or cast it is you are doing KNSU the 'rocketry' way), you will be creating the core by carefully drilling in to the nossle, and then deep in to the fuel.

 

How are you prepairing the fuel, and what fuel are you using? If it is cast KNSU, only the sucrose melts, so the Potassium nitrate needs to be very finely powdered. If it is rammed, everything must be very fine.

 

While Fe2O3 is not needed, you should not have trouble getting it. It is avaliable at pottery suppliers and some hardware stores for next to nothing.

 

Metal powders may be great forfirework production, but for sugar rockets, they are not used, with the rare exception of Titanium to make a sparky tail.

 

There are lots of mixtures, from the basic 65% Potassium nitrate and 35% Sucrose, with or without +1% Fe2O3, to the teleflite mix, which is 63% Potassium nitrate, 27% Sucrose and 10% Sulfur. The first can be cast or rammed, while the second should be rammed. you do not want to add sulfur to molten sucrose, unless you want to experience life in a volcanic vent. It melts and starts evaporating.

 

Typical dimensions for the nossle are that it is as thick as the tubes inside diameter, and the nossle will be one third of the tubes ID. The length of the nossle will vary, based on where it flies, and where it explodes in your experiments,. Sorry, these guidelines are rough.

 

I've only partially answered your questions. It is not safe to act on only what I've said. You need to research more. There is plenty of information to be had using the search fiunction of the forum (top right hand corner of the page), and on google.

 

One sirte, fairly advanced but vvery informative is that of Sugar rocket expert, Richard Nakka. He is one of the key players in the sugar-shot to space project.

http://www.nakka-rocketry.net/

 

Happy reading!

[TYRONEEZEKIEL]

Great explanation seymour!

 

Certainly more research is perfect! I personally dissolve my KNSU in water, add a small bit of honey, and then boil all water off. then pack into my casing. I find this method to be MUCH MUCH MUCH safer than melting the comp directly. There is Virtually no way for it to ignite unless you leave the work zone. Granted its pulled out of the heat once its solid.

[firetech]

Does honey work ok? I've only used Karo syrup. How do they compare?

BTW my ratios are 30/15/7 KNO3/Sucrose/Karo syrup

I cook it then do the 'snap test'.

[TYRONEEZEKIEL]

You have definitely been reading Jimmy Yawns stuff.!

 

Personally I think Honey works much much better than karo syrup. I think it helps bind somewhat-not-really. As I believe its fuel value is greater than karo.

 

 

Your ratios seem a bit off to me too. Try a side-by-side comparison between that and a 65/35/7 KNO3/Sugar/Honey. Remember dissolving in water and boiling takes a bit longer than other methods, but is much more superior. Also, if you are looking for thrust and burn rate, add 1-3% Iron Oxide.

[firetech]

I'm not fond of the texture that the iron oxide creates when added and it usually sets quicker when I'm molding it, so I usually leave it out. I only use it in small estes size C model rocket motors. I'm not sure about the stoichiometry of the propellant and perhaps your fuel is closer to the right ratio. Although my formula has worked very well and it is VERY powerful even in the absence of a catalyst.

[derekroolz]

Ok...

 

A core is a cavity through the centre of the motor which increases the surface area, and therefore the thrust. With KNSU (yes, that means Potassium nitrate/Sucrose) you will need a core to get a flight. Unless you have tooling which creates a core as you ram or press the fuel (or cast it is you are doing KNSU the 'rocketry' way), you will be creating the core by carefully drilling in to the nossle, and then deep in to the fuel.

 

How are you prepairing the fuel, and what fuel are you using? If it is cast KNSU, only the sucrose melts, so the Potassium nitrate needs to be very finely powdered. If it is rammed, everything must be very fine.

 

While Fe2O3 is not needed, you should not have trouble getting it. It is avaliable at pottery suppliers and some hardware stores for next to nothing.

 

Metal powders may be great forfirework production, but for sugar rockets, they are not used, with the rare exception of Titanium to make a sparky tail.

 

There are lots of mixtures, from the basic 65% Potassium nitrate and 35% Sucrose, with or without +1% Fe2O3, to the teleflite mix, which is 63% Potassium nitrate, 27% Sucrose and 10% Sulfur. The first can be cast or rammed, while the second should be rammed. you do not want to add sulfur to molten sucrose, unless you want to experience life in a volcanic vent. It melts and starts evaporating.

 

Typical dimensions for the nossle are that it is as thick as the tubes inside diameter, and the nossle will be one third of the tubes ID. The length of the nossle will vary, based on where it flies, and where it explodes in your experiments,. Sorry, these guidelines are rough.

 

I've only partially answered your questions. It is not safe to act on only what I've said. You need to research more. There is plenty of information to be had using the search fiunction of the forum (top right hand corner of the page), and on google.

 

One sirte, fairly advanced but vvery informative is that of Sugar rocket expert, Richard Nakka. He is one of the key players in the sugar-shot to space project.

http://www.nakka-rocketry.net/

 

Happy reading!

Thank You so much for the information i went to the website site you recommended and holly crap there was so much to learn and i already made a successful rocket last night i thank you so much this is the beginning of an official amature rocketeer

[TYRONEEZEKIEL]

The candy with honey is perfect without the catalyst. Ive never used it myself.

 

Here are a few of my ooooold videos of my nozzless rcandy.

 

Very tightly packed stuff, check at 2:14! I wonder whats happening here with the purple twisting plume? Edited June 27, 2009 by TYRONEEZEKIEL

[RickM]

Our largest 'successful' sugar motor: https://www.youtube.com/watch?v=ykLyrmrDKg8

 

Rick

[Redrocketman]

Have u just joined Rick?? I'll let u know who I am in AER!!! ( think, think, think!!!)

 

R candy is amazing stuff with great potential for experementation. There are many ways to prepare it, many different sugars and many different motors it will work in ( anything really!! )

 

For the newer guys & those having a bit of trouble, u must research!! There is more tutorials online than I've had roast dinners! Like cooking, the recipe must be followed and measurements MUST be accurate. 65kno3 35Su. 60/40 is easier to deal with when starting out, as it will be more pourable, with a small decrease in performance. Coring the cast fuel will give much better performance, having much more surface area of the fuel burning at once. Remember, as pressure rises in the motor, the burn rate will increase. Therefore having a nozzle of correct dimensions effectively chokes the exhaust gasses, increasing pressure, increasing burn rate. That's why u see big sugar motors on YouTube or whatever expending huge quantities of fuel in a very short time. ( eg my H class motoris 1" X 8" with a 1.8sec burn time, I/low J class is1" X 18" with a 1.9 - 2sec burn time, funny seeing the I/J has twice the fuel...)

 

Trust me, when u get it right you'll be so happy, then with time you build them so powerful u cringe every time before flicking the switch!!

[Redrocketman]

Tyrone, I'm sorry, but I don't believe dissolving in water is much more superior??? I understand the theory, and of course, have used every method known. But if dry melting and both the fuel and the oxidiser are ground sufficiently, ( more the kno3 ) the kno3 particles are completely suspended in the Su, with the added bonus of ensuring there is no residual water. I add Karo also, and the residual water from that is enough. Only my opinion tho!!

[pyro159]

How critical is it to have the kno3 finely powdered? And does adding propylene glycol help with the viscosity or was it glicerine?

[Redrocketman]

Important. Kno3 has a much much higher melting point than sugar or their derivatives. When " cooking the propellant mixture the sugar melts, and the kno3 particles are suspended in the now liquid sugar. The finer the kno3 particle size more surface area is in contact with the sugar mixing the 2 more intamatly. Tho, the finer the kno3 the thicker the viscosity of the prepared fuel, making casting a bit more difficult. I use dextrose, as it's a good compromise between sugar and sorbitol which, while being superior in most ways is just too expensive here. Dextrose is excellent I believe, I cast straight from the pot grains from 3/4" X 1-1/4". up to 2.5 X 4. Easy as and excellent performance

[jbeuckm]

Trying to run Burnsim for 65/30/5 rcandy that I dissolve and boil off... I found figures here from Nakka: http://www.nakka-rocketry.net/succhem.html

 

In Burnsim, if I put in 3106 for C*, it sets the Char ISP to 96.6. But if I set Char ISP to 130, it sets C* to 4184.7!

 

How can I choose good values for simulation? The max pressure is significantly different and I really don't want to RUD my PVC.

[jbeuckm]

Welp, I broke apart a 1" PVC motor with a terrifying boom. Either Burnsim setting would have had the pressure below 1000psi but I imagine there was erosive burning because my port/throat was too low. I'm going with 130 ISP for my simulations from now on, upping port/throat to >2 and installing a 6" PVC sleeve around my test stand. I don't want to see that kind of explosion again.

[MagnumMoose]

I've been milling my sucrose down to powder to use in the 63/27/10 mix. Can I instead use the powder sugar that contains starch? It's the only kind of powdered sugar available to me.

[JMan]

Honestly guys I disolve it in water and boil it off. I can't speak statistacly that it is better, but if you can acuretly measure the temp of the mix and keep ir right at about 160-165 C (340 F) it's very much a liquid almost so much that you can pour it into a large grain.

 

I like to follow it all mathematically. Getting the perfect 65:35 mix (it's really 13:7) so that the burn is complete and setting the temp to 160 so that water boils off and sugar dosnt carmilize is perfect. There will be NO water left at all and (mathematically at least) a perfect burn.

[NeighborJ]

Magnum and JMan the 65:35 mix is fairly close to what it needs to be, or at least it is a good starting point. When I do my strand test I'll burn a hunk and if it leaves a white blob of slag in the residue then it is too lean and requires a bit more fuel in the mix. Likewise if it leaves a black blob of tar then it needs more oxidizer.

 

I try to use the same brand of sugar and KNO3 every time because I've had to readjust the mix between brands. The difference isn't much but consistency is important with rcandy and I get a little OCD with it.

 

The powdered sugar works but it will have less fuel value so do the burn test and adjust. Note that the amount of starch could differ even when using the same brand.

[JMan]

Yah NJ a little bit of fine tuning is needed but chemically the 35:65 is perfect but of course you'll have a gram or two of impureties. You can look up (NFDA or something I can't remember the acronym) and it will tell you exactly what chemicles are in products like stump remover and sugar/powdered sugar. Great place to find out just how good of stuff your using.

 

Thankfully my two chemicles are just as impure the perfect 35:65 leaves nothing behind except a very slight bit of white (enough that it kinda vaporizes away in a couple of seconds)

 

You should almost never go past 60:30 or 70:40 unless your trying to really change the fuel (some additives call for less sugar) if you do have to break the 30's and 60's try a different brand of something.

[RickM]

I've tried lots of different sugar casting methods, we use dry mix and melt almost exclusively for any size motor.

Casting:

Static firing:

 

We have a 24" motor in the design stage

[Sulphurstan]

Did you record the thrust?

It looks quite huge..

Edited May 17, 2019 by Sulphurstan