If I recall correctly, red iron oxide is supposed to make the fuel burn somewhat faster, but if you use quite a bit*, it's supposed to reduce the pressure exponent. At least in Richard Nakka's RNX fuels, which actually use epoxy. I don't know if it works the same way with sugar motors. *7 or 8 percent in some cases
It is my understanding that it "should" have resulted in a faster burn rate which is what we wanted. But this fuel was already very difficult to ignite and the addition of iron oxide made it extremely difficult to light with a standard e-match.
That was one of the Myth Buster shows I worked on. We tried 'true' gummy bear rocket fuel in a hybrid with LOX but the high water content (15-25%) in gummy bears hinders its use as a fuel without modifications. Cooking it down as you did (with potassium nitrate) removes much of that water content as does drying it out further as a powder as on the Myth Buster show (still a true gummy bear fuel). They switched to ammonium perchloate (AP) instead of potassium nitrate (KNO3) for their oxidizer.
Nice! I did see the terribly failed experiment with plain gummy bears. That was doomed from the start but you probably knew that going into it. I was disappointed in the gummy bear myth busters episode where they successfully launched the bates grain fuel motor. Mostly because the didn't really do anything other than commentary and push the launch button. They didn't build the rocket, the fuel or the motor... All done by someone else... Maybe you :) It really looked to me like the bates grains they showed were constructed of APCP with just some of the dried gummy bear mixed in. My assessment of that was based on Jamie's description of the fuel.
@@rotaryrocketryAP works many times better as an oxidizing agent than kno3 and true APCP uses htbp as a binder and as a sort of fuel but it mainly uses powderd aluminium as fuel so i think what they did was lower the amount of htbp and replace the aluminium with gummy bear powder so most of the impulse still came from the gummy bears
Well, I don't doubt that "some" of the impulse came from the sugar content of the gummy bears but just how much is up for debate. They were deliberately not sharing detailed information about the fuel on the show. I've actually been thinking about re-visiting this idea since we've made some significant motor design improvements. And maybe melting and pulverizing the gummy bears like they did on the show... It's a possible future project.
@@rotaryrocketry i think it would be fun to revisit the project and maybe try AP instead of kno3 to see if it would work better and try the dried fuel i think that the dried gummy bear fuel would work a lot better i have been thinking trying some sugar rockets (i bought a 5kg bucket of kno3 like a year ago never used it yet) as a young rocketeer in europe atleast i my country i am basicly the only young person to do rocketry at a bigger scale using some smaller apcp motors which are stupidly expensive because of import taxes and such to a point where a simple G rocket motor can cost up to 50€ (about 55$) so sugar rockets might be a good option but i dont know if i am allowed to even launch them at my club i think i will post a video on an upcoming club launch this sunday know i dont know why i made such a long comment but you make great content Support from the netherlands👍
Youuuuuu know... if those were 'special' gummy bears, you'd get your rocket higher than... well, it would get pretty damned high, let's leave it at that.
That pulsing is odd and I wonder if it is caused by the gelatin tuning to some species that doesn't burn as well as the sugar and somehow insulating the sugar from the flame front momentarily.
Absolutely. Our standard sugar fuel uses powdered sugar & Karo syrup. Here are two of our videos that have detailed information about making Flexi-Fuel using Karo syrup. ruclips.net/video/WrvOPYNQv_g/видео.html ruclips.net/video/wJt1XLjqaGY/видео.html
@@rotaryrocketry Karo syrup is excellent for making flexi-fuel, which itself is best suited to large single grains. Dan Pollino being the inventor of flexi-fuel explains this in detail in his book “how to build a big sugar rocket without losing a finger” I find a 65/35 mix of kno3/dextrose with or without 1% by weight RIO as a burn modifier as needed more suitable for bates grains, especially using pvc cases and nozzle retainers
Just wondering, you had over pressure with a 15 nozzle and low erratic burn with a 17 so why not try a 16? Very entertaining vid , keep up the good work atb
Good question and it shows you were paying attention. The burst of thrust that occurs at the end of the burn with the #17 nozzle is very powerful. Since we were only using a PVC case, I felt there was a good possibility the case would explode if we dropped to a #16. Also, the #17 nozzle one was the 9th test in the series and we really wanted to wrap up this project since we've been working on it for nearly a month. Since we knew it had enough power to launch a rocket, we went for it.
If I recall correctly, red iron oxide is supposed to make the fuel burn somewhat faster, but if you use quite a bit*, it's supposed to reduce the pressure exponent. At least in Richard Nakka's RNX fuels, which actually use epoxy. I don't know if it works the same way with sugar motors.
*7 or 8 percent in some cases
It is my understanding that it "should" have resulted in a faster burn rate which is what we wanted. But this fuel was already very difficult to ignite and the addition of iron oxide made it extremely difficult to light with a standard e-match.
Gummy Bear to his friends: You won't believe what i just experienced, it was wild.
That was one of the Myth Buster shows I worked on. We tried 'true' gummy bear rocket fuel in a hybrid with LOX but the high water content (15-25%) in gummy bears hinders its use as a fuel without modifications. Cooking it down as you did (with potassium nitrate) removes much of that water content as does drying it out further as a powder as on the Myth Buster show (still a true gummy bear fuel). They switched to ammonium perchloate (AP) instead of potassium nitrate (KNO3) for their oxidizer.
Nice! I did see the terribly failed experiment with plain gummy bears. That was doomed from the start but you probably knew that going into it. I was disappointed in the gummy bear myth busters episode where they successfully launched the bates grain fuel motor. Mostly because the didn't really do anything other than commentary and push the launch button. They didn't build the rocket, the fuel or the motor... All done by someone else... Maybe you :)
It really looked to me like the bates grains they showed were constructed of APCP with just some of the dried gummy bear mixed in. My assessment of that was based on Jamie's description of the fuel.
@@rotaryrocketryAP works many times better as an oxidizing agent than kno3 and true APCP uses htbp as a binder and as a sort of fuel but it mainly uses powderd aluminium as fuel so i think what they did was lower the amount of htbp and replace the aluminium with gummy bear powder so most of the impulse still came from the gummy bears
Well, I don't doubt that "some" of the impulse came from the sugar content of the gummy bears but just how much is up for debate. They were deliberately not sharing detailed information about the fuel on the show.
I've actually been thinking about re-visiting this idea since we've made some significant motor design improvements. And maybe melting and pulverizing the gummy bears like they did on the show... It's a possible future project.
@@rotaryrocketry i think it would be fun to revisit the project and maybe try AP instead of kno3 to see if it would work better and try the dried fuel i think that the dried gummy bear fuel would work a lot better i have been thinking trying some sugar rockets (i bought a 5kg bucket of kno3 like a year ago never used it yet) as a young rocketeer in europe atleast i my country i am basicly the only young person to do rocketry at a bigger scale using some smaller apcp motors which are stupidly expensive because of import taxes and such to a point where a simple G rocket motor can cost up to 50€ (about 55$) so sugar rockets might be a good option but i dont know if i am allowed to even launch them at my club i think i will post a video on an upcoming club launch this sunday know i dont know why i made such a long comment but you make great content
Support from the netherlands👍
Youuuuuu know... if those were 'special' gummy bears, you'd get your rocket higher than... well, it would get pretty damned high, let's leave it at that.
That pulsing is odd and I wonder if it is caused by the gelatin tuning to some species that doesn't burn as well as the sugar and somehow insulating the sugar from the flame front momentarily.
Sounds reasonable. It was definitely weird.
Funny as hell! (That's a compliment.)
12:25...great smoke bomb.
Would Karo Syrup work as fuel?
Absolutely. Our standard sugar fuel uses powdered sugar & Karo syrup.
Here are two of our videos that have detailed information about making Flexi-Fuel using Karo syrup.
ruclips.net/video/WrvOPYNQv_g/видео.html
ruclips.net/video/wJt1XLjqaGY/видео.html
@@rotaryrocketry Karo syrup is excellent for making flexi-fuel, which itself is best suited to large single grains. Dan Pollino being the inventor of flexi-fuel explains this in detail in his book “how to build a big sugar rocket without losing a finger” I find a 65/35 mix of kno3/dextrose with or without 1% by weight RIO as a burn modifier as needed more suitable for bates grains, especially using pvc cases and nozzle retainers
Just wondering, you had over pressure with a 15 nozzle and low erratic burn with a 17 so why not try a 16?
Very entertaining vid , keep up the good work
atb
Good question and it shows you were paying attention.
The burst of thrust that occurs at the end of the burn with the #17 nozzle is very powerful. Since we were only using a PVC case, I felt there was a good possibility the case would explode if we dropped to a #16. Also, the #17 nozzle one was the 9th test in the series and we really wanted to wrap up this project since we've been working on it for nearly a month. Since we knew it had enough power to launch a rocket, we went for it.
great kkkk