Jump to content
APC Forum

Best sugar for Rocket?


bryann

Recommended Posts

Hi guys, does any of you use cheap bag of kane sugar and KNO3 for their rocket? If don't mind, please share what's the best kind of sugar best use for small rocket engine. Thanks.
Link to comment
Share on other sites

Hi guys, does any of you use cheap bag of kane sugar and KNO3 for their rocket? If don't mind, please share what's the best kind of sugar best use for small rocket engine. Thanks.

 

I have used both granular and powdered Beet and Cane sugar with similar results in rockets but I have found that some powdered sugars contain other ingredients such as starches that tend to slow the burn.

 

Others have reported difficulty in getting granular sugar to melt adequately in a pan, I have had no such problem as I have made stock "simple syrup" in a 2:1 ratio of sugar to water for canning, drinks and such and use same for rocket fuel. I do the same with granulated KNO3 but it has to be kept hot or it will fall out of solution. At a rate of over 2 kilos per liter of water at 100°C, you can get a 2:1 ratio from this as well.

 

In practical terms, to make a 100g batch of sugar rocket fuel, you would pour 120g of the "K-syrup" along with 80g of "simple syrup" into an electric pan and heat to your desired color and temper. I add 2g of corn syrup to the batch before it starts to turn color if I am pressing it into casings or just use it 60:40 if I am going to grate it for pressing into casings as one would with BP.

 

-dag

Edited by dagabu
Link to comment
Share on other sites

Id suggest using Dan Pollino's fuel.

 

http://www.jacobsrocketry.com/aer/caramel_candy_propellant.htm

 

"Dan Pollino and "Flexible" Sugar Propellant

Dan Pollino's "flexible" propellant is just a variation of Jimmy's propellant but he mixes it differently. Where Jimmy's formulas are a little fuel rich, Dan's "flexible" sugar propellant is a little oxidizer rich when you take into account the amount of water in Corn syrup. His formula is:

65% Potassium Nitrate

15% Sucrose (Powdered Sugar)

19% Corn Syrup

His mixing method is: First mix thoroughly the potassium nitrate (ground fine) and powdered sugar. Next, heat up the Corn Syrup to 180° F, then stir in the potassium nitrate and powdered sugar. Stir constantly. When the mix is at 210 degrees, it is ready for casting."

 

Link to comment
Share on other sites

As far as rocketry goes, all the rocket guys use sorbitol instead of powdered sugar or table sugar. with the ratio of 65:35 KNO3:Sorbitol.

 

Since sorbitol is a sugar alcohol it melts significantly easier and is much more workable IMO. The major drawback is availability. Standard sugar is significantly cheaper and more available.

 

If you are just looking for a very powerful rocket formula, try the flexible formula above. That is more or less what I use, however I think the corn syrup amount is too high. I usually cut it to 10% and fill it in with sugar. I have also been experimenting with honey instead of corn syrup. And I find that boiling all the water out makes a much stronger propellant.

 

If you do go with the boiling route, make sure you add enough water in the beginning to completely dissolve the powders, then gradually boil all the water off until you are left with a light colored peanut buttery mass. This will ensure the best possible mix of chems as well as increase safety by reducing flare ups.

Link to comment
Share on other sites

Dude, I looked for sorbitol forever... Impossible to find, and when I did fine someone... It was being discontinued and they canceled my order out of stock! It's no longer used in food because of it's problems.
Link to comment
Share on other sites

Use Dan Pollino's fuel, is east to work and easy to make, cheap, and you can find the chemicals everywhere, i use it and i make some big engines like J and K class
Link to comment
Share on other sites

Yess... Thumbs up. :D Dan's fuel unlike other methods of making sugar fuel gives you the EXACT same results every time... It rules!!!

 

Use Dan Pollino's fuel, is east to work and easy to make, cheap, and you can find the chemicals everywhere, i use it and i make some big engines like J and K class

Link to comment
Share on other sites

Id suggest using Dan Pollino's fuel.

 

http://www.jacobsroc..._propellant.htm

 

"Dan Pollino and "Flexible" Sugar Propellant

Dan Pollino's "flexible" propellant is just a variation of Jimmy's propellant but he mixes it differently. Where Jimmy's formulas are a little fuel rich, Dan's "flexible" sugar propellant is a little oxidizer rich when you take into account the amount of water in Corn syrup. His formula is:

65% Potassium Nitrate

15% Sucrose (Powdered Sugar)

19% Corn Syrup

His mixing method is: First mix thoroughly the potassium nitrate (ground fine) and powdered sugar. Next, heat up the Corn Syrup to 180° F, then stir in the potassium nitrate and powdered sugar. Stir constantly. When the mix is at 210 degrees, it is ready for casting."

 

 

Yes, Dan's fuel stays workable longer but the use of more corn syrup and powdered sugar slow the burn and with an inhibited Bates grain, the burn should be more enthusiastic. I have not made a J-sized bates grain since 2006 and have no idea what Jimmy is doing with his sugar shot to the moon but as late as 2006, the use of sorbitol was limited to the HP rocketry snobs that were impossible to deal with as humans. That is the one hobby where there is more arrogance then a Doctors convention!

 

Us humans that wished to shoot a lawn-dart on a limited budget used sugar by C&H right from the bag.

 

Forgive my bitterness but HP rocketry left a very bad taste in my mouth....

 

-dag

Link to comment
Share on other sites

  • 1 month later...

Forgive my bitterness but HP rocketry left a very bad taste in my mouth....

 

-dag

 

Hmmm. I've yet to experience that arrogance though. Maybe they have matured or were going through a phase in life :D

 

bryann, here is a good link to read http://www.jamesyawn...candy/index.htm and http://www.jacobsroc..._propellant.htm

 

My preference in fuels from most to the least are as follows:

 

1. recrystallized sugar (KN/Dextrose, 65:35) (Dextrose also known as glucose)

2. recrystallized sugar (KN/Sucrose/Dextrose) (65/20/15)

3. recrystallized (james yawn formula)

4. Melted method (KN/Dextrose)

5. Melted method (KN/SU/Dextrose)

6. Melted method (KN/SU/Karo)

 

But all the pros seem to use KN/sorbitol which I cannot afford.

 

the recrystallized methods gives the best burn as the fuel and oxidizer are more intimately bonded.

The melted method requires grinding the already powdered KNO3.

Melted method more suited to larger motors, I class and above.

 

I love pure dextrose comps, it's cheaper than sorbitol, available, does not ignite easily while preparing, flexible and less hygroscopic than any mix with Sucrose.

Edited by donperry
Link to comment
Share on other sites

I also prefer re-crystallized dextrose, except I like to use a 60/40 ratio of Kn/Dextrose to make the propellant easier to work with. For the dextrose either buy it at a health food store or you can use straight corn syrup. The corn syrup I use is the "Garden Club" brand form the local grocery store. It may be hard to determine the exact amount of sugar in corn syrup but I came pretty close and it works just fine. What I did to determine the sugar content was first I measured a microwave safe pyrex dish. I then added some corn syrup and weighed the dish again so I knew how much syrup I had in the dish. I then micro waved the corn syrup just to the point that I noticed a slight change in color or carmalization. The idea being that you boil the water off until you start chemically splitting water from the sugar. I then weighed the dish with the cooked corn syrup and calculated the percentage of weight lost. It turned out that the corn syrup was about 79% sugar so I just rounded it up to 80% and this has worked great for me.

Also don't bother with using epoxy to bind the propellant to the inhibitors or motor tube like Jimmy does. Instead make a 50/50 solution of corn syrup to water and paint it on what ever surface you want the propellant to bond to. Next let the sugar solution dry, sometimes it is easiest to place the paper inhibitors in an oven at 150 for a few minutes, the hot propellant will bond with this sugar coating when it cools down. I will cook the propellant until it is ready to be formed into grains, I then push the propellant down into the prepared inhibitor and using an oiled aluminum knitting needle make the core while the propellant is still hot. Dextrose propellant does burn slower than sucrose but you can easily compensate for it with a smaller nozzle core. Also if you want to make a time delay bulk head with the propellant you need to add 1% iron oxide to keep the propellant lit as the chamber pressure drops after burn out. This the basics for my sugar motors I hope it helps.

 

Link to comment
Share on other sites

I realize that "motor class" is in newtons and "pounds" is in tube size but is there some sort of approximate translation from, say, a 1 LB rocket to a E class motor?
Link to comment
Share on other sites

I realize that "motor class" is in newtons and "pounds" is in tube size but is there some sort of approximate translation from, say, a 1 LB rocket to a E class motor?

 

Im not really sure about how to go around that. I do know that Sugar Rocket fuel takes twice the amount of comp to produce the equivalent power to BP IIRC. Or it may be to APCP.

 

Its been a long while since I've worked with sugar rocket fuel. Any confirmation on this?

Link to comment
Share on other sites

Performance

Sugar based rocket propellants have an average Isp(specific impulse) of between 115 and 130 seconds. Compare that to the average Isp of an APCP (Ammonium perchlorate composite propellant), which is 150 to 180 seconds. Sorbitol and KNO3 based propellants with a typical 65:35 ratio are capable of a max thrust of up to 110 N, an Isp of between 110 and 125 seconds, and may have an average thrust of about 40 N. However, sorbitol and KNO3 rockets with additives have been recorded as having average thrusts of up to 100N, total impulses of up to 735 Ns, and specific impulses of up to 128 seconds.

 

Xylitol and KNO3 based rocket propellants are capable of a specific impulse of ~ 100 seconds and can have a total impulse of up to 230Ns These have a unconfined burn rate of about 1.3 mm/sec.

 

Dextrose and KNO3 based fuels are capable of an average thrust of ~80N, a total impulse of 144 Ns, and an Isp of 118 seconds.

 

 

Performance

The impulse (area under the thrust-time curve) of a black powder motor is used to determine its class. Motors are divided into classes from 1/4A to E, which covers an impulse range of 0 to 40 Ns (Newtons*seconds). Other types of model rocket motors can be classified up to an ‘H’, which is up to 320 Ns, and even further in some cases. Each classes upper limit is double the upper limit of the previous classes.

For miniature black powder rocket motors (13 mm diameter), the maximum thrust is between 5 and 12 N, the total impulse is between .5 and 2.2 Ns, and the burn time is between .25 and 1 second. For Estes ‘regular size’ rocket motors (18 mm diameter), there are three classes: A, B, and C. The A class 18 mm motors have a maximum thrust between 9.5 and 9.75 N, a total impulse between 2.1 and 2.3 Ns, and a burn time between .5 and .75 seconds. The B class 18 mm motors have a maximum thrust between 12.15 and 12.75 N, a total impulse between 4.2 and 4.35 Ns, and a burn time between .85 and 1 second. The C class 18mm motors have a maximum thrust from 14 – 14.15 N, a total impulse between 8.8 and 9 Ns, and a burn time between 1.85 and 2 seconds.Figures from tests of Estes rocket motors are used in the following examples of rocket motor performance.

 

There are also 3 classes included in Estes large (24 mm diameter) rocket motors: C, D, and E. The C class 24 mm motors have a maximum thrust between 21.6 and 21.75 N, a total impulse of between 8.8 and 9 Ns, and a burn time between .8 and .85 seconds. The D class 24 mm motors have a maximum thrust between 29.7 and 29.8 N, a total impulse between 16.7 and 16.85 Ns, and a burn time between 1.6 and 1.7 seconds. The E class 24 mm motors have a maximum thrust between 19.4 and 19.5 N, a total impulse between 28.45 and 28.6 Ns, and a burn time between 3 and 3.1 seconds.

 

-WP-

Edited by dagabu
Link to comment
Share on other sites

Also if you want to make a time delay bulk head with the propellant you need to add 1% iron oxide to keep the propellant lit as the chamber pressure drops after burn out. This the basics for my sugar motors I hope it helps.

 

 

I agree. I once used a 1/2 inch CPVC pipe for my delay grain. I had red iron oxide in it. Really keeps it going.

Link to comment
Share on other sites

Also if you want to make a time delay bulk head with the propellant you need to add 1% iron oxide to keep the propellant lit as the chamber pressure drops after burn out. This the basics for my sugar motors I hope it helps.

 

Does anybody know why this is happening ? why when the motor΄s chamber pressure drops after burn out the delay grain has the tendency to lit off ?

Link to comment
Share on other sites

Hmmm. I've yet to experience that arrogance though. Maybe they have matured or were going through a phase in life :D

 

 

Ummm... no.

 

The rocketry folk are well known for eating their young. I've mostly moved away from the hobby, though I still fly locally and participate with outreach efforts - anything to get kids interested in science.

 

Kevin

Link to comment
Share on other sites

Ummm... no.

 

The rocketry folk are well known for eating their young. I've mostly moved away from the hobby, though I still fly locally and participate with outreach efforts - anything to get kids interested in science.

 

Kevin

 

For me it was more of the have-have nots. The groups with lots of money completely ignored smaller groups with small budgets. We were in the middle money-wise but still struggled to be treated fairly on launch day.

 

-dag

Link to comment
Share on other sites

None of that seems to be present in independent amateur groups, must be exclusive with the Tripoli/NAR crowd. Though pyro is certainly more grassroots and laid back, probably because its more art than science.
Link to comment
Share on other sites

None of that seems to be present in independent amateur groups, must be exclusive with the Tripoli/NAR crowd. Though pyro is certainly more grassroots and laid back, probably because its more art than science.

 

I like that, "probably because its more art than science."

 

-dag

Link to comment
Share on other sites

  • 3 weeks later...

None of that seems to be present in independent amateur groups, must be exclusive with the Tripoli/NAR crowd. Though pyro is certainly more grassroots and laid back, probably because its more art than science.

 

I did visit another rocketry site and the whole idea of PVC motor was shot down as I mentioned it, and then someone send me a PM with nakka's website and told me I shouldn't listen to them :))

I left that site and stuck to the sugpro mailing list. There is just enough talent there (nakka, james yawn, Scott, sasha, kelly, etc) that were always willing to help :)

 

I have since created my own website to log my experience "pvcrocketry.com"

Link to comment
Share on other sites

  • 4 months later...
I have tried the re-crystalized method a few times and have found it to be a bit time consuming versus Dan Pollino's method. I did take a little liberty with the mix and added 1% of total mass of RIO (Fe2O3) to decrease the burn time and get the fuel out of the casing quicker just to avoid any possible melting or case weakening problems. With Dan Pollino's fuel the safe working KN is around 300 but with the RIO added and the burn rate being fairly quick, I don't really know the safe KN for that formula.... yet. Any input would be greatly appreciated.
Link to comment
Share on other sites

  • 1 month later...

You prob got your answer already as you posted back in august, but Dan polino's fuel is perfect for his long case bonded motors. His casing pressure rarely hits 500psi and maintains a slightly progressive burn.

Adding all of 1% RIO (yea, that's alot!) could make the pressure rise very sharply, going into something like a pressure loop where more pressure causes faster burning, causes more pessure, etc.

 

I would try a KN of < 200.

Link to comment
Share on other sites

Erythritol is another good fuel to use for rocket grains.

You might want to check out Scott Fintels website, he has some good videos.

He will show how he makes his rocket grains, safe and easy.

www.thefintels.com

 

Mikeee

Link to comment
Share on other sites

×
×
  • Create New...