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GeoffinIN
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« on: March 28, 2014, 09:51:30 AM » |
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Given the demise of Jetex and Rapier, is it at all practical to consider making slow burning rocket fuel using sucrose/potassium nitrate with some sort of retarder added? I recently stumbled upon a 1951 patent filed by the Aerojet General company regarding polyester resins in slow burning rocket fuel. Way beyond my comprehension, but maybe one of you chemists can comment on the possibilities? http://www.google.com/patents/US3031347 Too expensive or too toxic for consideration here? |
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dosco
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« Reply #1 on: March 28, 2014, 09:55:16 AM » |
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It's possible, but I have to admit I haven't studied it closely.
If you google "Richard Nakka" and goto his page, you can download a motor sizing spreadsheet ... it helps you determine nozzle configuration/dimensions, etc.
Might be worth a look.
Regards-
Dave
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Bulldogger
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« Reply #2 on: March 28, 2014, 01:31:49 PM » |
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This question immediately brought R Candy rocket fuel to mind, but I've never played with it (YET).
Perhaps someone can weigh in.
I guess it's not feasible to just jig up an A motor then?
Please excuse my ignorance, I've never seen or expoerienced Jetex or Rapier in person.
Bulldogger
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Steven Wrigley
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« Reply #4 on: March 28, 2014, 06:44:46 PM » |
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I made up a batch just play with but I left it in a lump and burnt it that way. The energy density pretty shocking considering its just sugar and an oxidizer. I haven't played around with the fuel/oxidizer mixture yet as at that time I didn't have a scale.
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My other Saab's a jet!
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GeoffinIN
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« Reply #6 on: March 28, 2014, 08:25:32 PM » |
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Thanks, guys, for all the links. I've never played with Rapiers, and haven't had a Jetex since the 1950s, when I was a pre-teenager. I'm trying to get a second childhood going here, y'see.  As for holding a rocket, home or factory made, to my head during launch, I wouldn't either. A launch ramp would be my way to go. |
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Steven Wrigley
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« Reply #7 on: March 28, 2014, 08:47:13 PM » |
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I would still like to try makiing a homemade Rapier motor, but edf would be a much simpler and easier way to go. And I wouldn't have to keep rolling motor casings. And electricity is cheap.  But fire is fun. |
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My other Saab's a jet!
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carpetbagger
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« Reply #8 on: March 28, 2014, 09:33:53 PM » |
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Matchbook heads. Cut the burny part off witha razor, pack it in, stick in a wick, light `er off. Using matchhead fuel packed in an empty CO2 container with all the soft puncture end cut out and lanched out of a pipe me'n my pal split a 2x12 at about 20 yards and then ... EEK! the canister punched a hole in a cinder block garage wall. No animals or automobiles were harmed that day.
Also mixed sulpher and tannic acid powder and launched many a homemade rocket, managed to set a field on fire due to a launch mishap, and later blew a hole in my bedroom ceiling while trying to melt the mix slightly to make a solid charge.
Yes, my Mother's hair did seem to go gray sooner than it should have . . .
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Copbait73
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« Reply #9 on: March 29, 2014, 09:24:21 AM » |
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Thanks to eBay there is no shortage of Jetex fuel and motors. I'm not interested but that seems like the best route for fire and smoke FF.
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GeoffinIN
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« Reply #10 on: March 29, 2014, 01:00:19 PM » |
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Marty, I was under the impression that the currently available fuel is either too old to burn well or just plain junk. Maybe I'm wrong. However, you've really piqued my interest with your mini-EDF stuff! Looking forward to your having the time to show them to me. Somehow, I don't think my collection of Ramtec, Dynamax, Turbax and Kress fans will fit in an FAC-scale model!  |
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sparapiselli
Nickel Member
Kudos: 0
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Posts: 2
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« Reply #11 on: March 29, 2014, 03:14:13 PM » |
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Not always the pellets JETEX being old, do not burn well. The burning depends on how they were stored. In this day I bought on EBAY 70 pellets suitable for engines JETEX 100, JetMaster and PAALOADER and just today I have test one and worked perfectly.
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Copbait73
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« Reply #12 on: March 29, 2014, 05:01:10 PM » |
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Marty, I was under the impression that the currently available fuel is either too old to burn well or just plain junk. Maybe I'm wrong. However, you've really piqued my interest with your mini-EDF stuff! Looking forward to your having the time to show them to me. Somehow, I don't think my collection of Ramtec, Dynamax, Turbax and Kress fans will fit in an FAC-scale model! Sorry the week ended and I didn't free up time. Will PM you. Regarding fuel, as I understand most vintage JETEX is OK. Stuff sold as JET-X is more recent and has real issues. |
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dosco
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« Reply #13 on: January 03, 2022, 06:33:54 PM » |
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What happened to this group? I'd like to revisit this subject, and am scrabbling about ... Best- Dave |
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lincoln
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« Reply #14 on: January 04, 2022, 07:12:49 PM » |
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Fireworks outfits sell delayed fuse material of various speeds. I wonder if that would be a good substitute for Jetex pellets and if you need to have some kind of crazed explosive user license. Also if ATF, etc. keep track of who buys. Seems like the fuse would have to be reliably consistent, or it would be blowing people up.
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kittyfritters
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« Reply #15 on: January 04, 2022, 07:30:40 PM » |
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Back in the 50s the science club I was in built sizable rockets fueled by a mixture of sugar and ammonium nitrate. We melted it in an electric frying pan and poured it into the rockets to make a solid charge. My father, a real rocket scientist, was horrified since the temperature control of an electric frying pan is not that accurate however, we did not have any accidents. The power was good, but it left a spectacular smoke trail and you to use them right after they cooled since the mixture will absorb moisture if stored for any length of time. I don't know if the moisture problem can be solved to make Jetex pellets and if you tried to buy ammonium nitrate you will be put on a terrorist watch list.  KF |
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Qua sublata omnia praecepta legis
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Copbait73
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« Reply #16 on: January 04, 2022, 08:21:22 PM » |
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Rapier type motors were never reliable, nor consistent in power or availability, and they were expensive but they were fun while they lasted. There is always Jetex motors, fuel, and fuses auctioned on eBay.
I don’t advise the Jet-X fuel. It is worthless.
There are small EDF options now if you want a 13-15” wingspan jets. This is the better route.
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faif2d
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« Reply #17 on: January 04, 2022, 11:13:55 PM » |
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I remember one of copbait's models at Geneseo going WAY high for about 1 min or more. Really inspiring!
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I used to like painting with dope but now I can't remember why! Steve Fauble
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flydean1
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« Reply #18 on: January 05, 2022, 03:50:16 PM » |
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Source for the liddle iddy biddy fans?
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GeoffinIN
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« Reply #19 on: January 14, 2022, 05:51:34 PM » |
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lincoln
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« Reply #20 on: January 17, 2022, 02:10:35 AM » |
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Richard Nakka's page,linked in the first post, has information on a rocket propellant called RNX, which doesn't have to be cooked. Potassium nitrate and epoxy, with some aluminum and/or iron oxide dust, if I remember correctly. Of course, the real question is if there's a way to make it slow enough.
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Pit
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« Reply #21 on: January 17, 2022, 01:04:12 PM » |
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Source for the liddle iddy biddy fans?
Unfortunately, I don't think that the liddle iddy biddy fan (24mm) is being made any more. It's been "inactive" on the KP site for quite a while. Maybe a note to them will result in a unit or two being put together - similar to the CO² adapter. |
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A Dedicated Convert to:
WWWoFF (Wonderfull Wacky World of Free Flight)
Comparing Spammers to a pile of organic waste is an insult to the organic waste!
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Crabby
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« Reply #22 on: January 17, 2022, 02:11:18 PM » |
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The Threadkiller!
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GeoffinIN
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« Reply #23 on: January 17, 2022, 04:00:31 PM » |
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Source for the liddle iddy biddy fans?
Unfortunately, I don't think that the liddle iddy biddy fan (24mm) is being made any more. It's been "inactive" on the KP site for quite a while. Maybe a note to them will result in a unit or two being put together - similar to the CO² adapter. I did just as you suggested and Derek replied that they are still available, but the picture has mysteriously disappeared from his website. Whew! That's a relief! Geoff |
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dosco
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« Reply #24 on: January 18, 2022, 01:34:26 PM » |
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Since rocket propellant deflagrates and does not detonate, I don't think there's any problem here. Also, Nakka's site is still up and running ... More seriously, I'm tempted to contact Richard and ask for some guidance on how to formulate a low-impulse, slow burning, propellant. Lincoln's comment - err, I don't think there's a way to "slow" the RNX. Another issue with RNX is the need for teeny nozzles (back in 2007-ish, I was looking at having a go at making RNX. The nozzle geometry doesn't lend itself to small motors ... the throat diameters are teeny). Best- Dave |
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