dagabu Posted June 23, 2011 Posted June 23, 2011 (edited) Have you ever heard of JATO rockets? Well, in the 1940's, they were used by the NAVY on aircraft carriers but the pot perc and asphalt made smoke that they didn't like so they moved on to other comps but I have made a few original JATO fueled rockets and the results are... interesting. http://www.youtube.com/watch?v=MVT38no8C_o -dag Oh, and here is one that didn't do so well http://www.youtube.com/watch?v=cTdUdlKpzoQ Edited June 23, 2011 by dagabu
guntoteninfadel Posted June 23, 2011 Posted June 23, 2011 I really love the slow take off, but boy do they pick up speed fast! I AM NOT going to try this but do tell how you accomplished this. Did you go dig up a piece of pavement and grind it? Wonder what they look like at night......(hint hint)?
dagabu Posted June 23, 2011 Author Posted June 23, 2011 LOL! No, I got a 20# box of Asphaltum from Cracker and combined 80 parts of pot perc, 20 parts of asphaltum and 5 parts of dark aluminum together, pressed them into a nozzled 1# casing (Universal Rocket Tooling) and lit it off. This one didn't do so well... you do need a nozzle. http://www.youtube.com/watch?v=ZTF7wKDgmd8 -dag
alexthegreat00 Posted June 24, 2011 Posted June 24, 2011 I bet most people have heard of this story, but for those who have not here it is. It is probably not true but I still like it. The Arizona Highway Patrol were mystified when they came upon a pile of smoldering wreckage embedded in the side of a cliff rising above the road at the apex of a curve. The metal debris resembled the site of an airplane crash, but it turned out to be the vaporized remains of an automobile. The make of the vehicle was unidentifiable at the scene. The folks in the lab finally figured out what it was, and pieced together the events that led up to its demise. It seems that a former Air Force sergeant had somehow got hold of a JATO (Jet Assisted Take-Off) unit. JATO units are solid fuel rockets used to give heavy military transport airplanes an extra push for take-off from short airfields. Dried desert lakebeds are the location of choice for breaking the world ground vehicle speed record. The sergeant took the JATO unit into the Arizona desert and found a long, straight stretch of road. He attached the JATO unit to his car, jumped in, accelerated to a high speed, and fired off the rocket. The facts, as best as could be determined, are as follows: The operator was driving a 1967 Chevy Impala. He ignited the JATO unit approximately 3.9 miles from the crash site. This was established by the location of a prominently scorched and melted strip of asphalt. The vehicle quickly reached a speed of between 250 and 300 mph and continued at that speed, under full power, for an additional 20-25 seconds. The soon-to-be pilot experienced G-forces usually reserved for dog-fighting F-14 jocks under full afterburners. The Chevy remained on the straight highway for approximately 2.6 miles (15-20 seconds) before the driver applied the brakes, completely melting them, blowing the tires, and leaving thick rubber marks on the road surface. The vehicle then became airborne for an additional 1.3 miles, impacted the cliff face at a height of 125 feet, and left a blackened crater 3 feet deep in the rock. Most of the driver's remains were not recovered; however, small fragments of bone, teeth, and hair were extracted from the crater, and fingernail and bone shards were removed from a piece of debris believed to be a portion of the steering wheel. Ironically a still-legible bumper sticker was found, reading "How do you like my driving? Dial 1-800-EAT-SHIT."
guntoteninfadel Posted June 24, 2011 Posted June 24, 2011 This one didn't do so well... you do need a nozzle. http://www.youtube.com/watch?v=ZTF7wKDgmd8 -dag Had several that performed close to that. Even had one come most of the way out of the launch tube just to sink back down. In the background you can hear, and I quote, "Oh yeah, it was supposed to do that......"
guntoteninfadel Posted June 24, 2011 Posted June 24, 2011 This is what I found...... btw, fwiw The original Darwin Awards were fictitious. Both were contained in a 1990 Version posted to rec.motorcycles of the JATO Rocket Car urban legend. When this urban legend was debunked, it was specifically pointed out that the mentioned Darwin Awards were fictitious. It contained a reference to the 1985 mention of a Vending Machine Tipover Darwin Award. It was Paul Vixie who wrote this introduction to the JATO urban legend that first included the term "Darwin Award". Vixie credits Charles Haynes with making the (informal) Darwin Award Nomination, but it was Vixie's specific wording, with the first sentence crediting Haynes stripped off, that was actually circulated and actually referred to the Darwin Awards as if they actually existed and were common knowledge, though the message wasn't widely circulated until it was reformatted. It remained fairly dormant until 1995, when the message surfaced again in rec.pyrotechnics with the email header stripped off the introduction, though the main story is still indented. Three days later the introduction is fully integrated into the story and it appeared on rec.humor in a form that made it a truly infectious meme. Shortly after it was reposted in 1995 it quickly began to spread, being posted on Usenet 24 times within the next month. In 1996 the legend was further embellished with references to the year of manufacture of the car and G-Forces and to the form which was widely circulated via email (55% of all postings on usenet which included "JATO Rocket Darwin Award impala" also included "g-forces"). Though this urban legend had apparently been around long before 1990, it appears to have been the addition of the Vixie Darwin Award introduction and the subsequent two edits to integrate that introduction and then posting on rec.humor that may have boosted its meme status and the 1996 embellishments almost doubled its popularity. Popularity peaked around the end of 1996. In 1996 after numerous inquires, the Arizona Department of Public Safety issued a news release posted on their website concerning the story. It termed the story "an Arizona myth." Forward to October 4, 2006: Paul Harvey's Morning Radio Show comments repeat the above story in a more encapsulated fashion. Cult of the Dead Cow, a high-profile hacker group and ezine, published an extensive elaboration in 1998 that in a detailed and plausible manner attempts to explain the most common details of the Rocket Car legend. Four adult males under 25 engaged in assorted illegal activity, welding, drinking, Rube Goldberg engineering, and scouting to build the rocket rail car when they happen upon JATOs in a junk pile. After a lengthy and well-written history of the car's planning, group dynamics, secrecy and construction, "CarInTheCliff" describes the car's only test in such a manner as to account for all the elements of the circulating legend plus the elements he has added while discouraging repeats by example. The Darwin Awards meme was also spread by Wendy Northcutt, who collected the Darwin Awards on a public website in 1993, and circulated new stories in a regular newsletter. [1] This according to www.wikipedia.com I think I sourced this right but if I screwed up just delete
shockie Posted June 24, 2011 Posted June 24, 2011 dagabu: do you cast or press these? Was the Asphaltum Gilsonite? JATO type rockets fuel was the first composite (if you don't count BP as a composite); invented by Jack Parsons with the able help of his machinist partner Edward S. Forman: http://www.bibliotecapleyades.net/bb/babalon004.htm They were quite the team in the early 1940's at JPL. They also experimented with all kinds of permutations involving BP and Smokeless Powder.....it's too bad all that most of this original work has disappeared in the haze of time and history.... Terry
dagabu Posted June 27, 2011 Author Posted June 27, 2011 I pressed these to 6500lpi and held the pressure for 15 seconds after the needle stopped moving to consolidate the grain. Each increment was 1/2 ID and I used Asphaltum Gilsonite as you said for the asphalt. I was given some advice on these to choke the rocket (use a nozzle) and use two to three increments of BP to get the rocket up faster and then let the Asphaltum Gilsonite fuel take over after that. -dag
WSM Posted June 27, 2011 Posted June 27, 2011 I experimented a little with a similar composition (without metal) many years ago and didn't get more than a bubbly mess... until I added a few percent of potassium benzoate. Then the stuff jumped up and came to life, showing serious potential for small rockets and thrusters. Asphaltum is an unpleasant material to work with so I abandoned further research with it. Have fun and keep sharing your efforts . WSM
dagabu Posted June 27, 2011 Author Posted June 27, 2011 I experimented a little with a similar composition (without metal) many years ago and didn't get more than a bubbly mess... until I added a few percent of potassium benzoate. Then the stuff jumped up and came to life, showing serious potential for small rockets and thrusters. Asphaltum is an unpleasant material to work with so I abandoned further research with it. Have fun and keep sharing your efforts . WSM I got 20# of the stuff, I have to figure it out so I can use it up! -dag
moondogman Posted June 27, 2011 Posted June 27, 2011 I got 20# of the stuff, I have to figure it out so I can use it up! -dag Cant you use it for cremora type fireballs?? Steve
dagabu Posted June 27, 2011 Author Posted June 27, 2011 Yes, but you need to mill it first to a fine powder, that's impossible in the summer. -dag
moondogman Posted June 27, 2011 Posted June 27, 2011 Hell you only have 3 weeks of summer left up there anyway. Steve
dagabu Posted June 28, 2011 Author Posted June 28, 2011 My friend, that is both silly and completely false, not to mention wrong, fall starts the day after the state fair and winter starts the day after Halloween... -dag
anapogeetoofar Posted July 11, 2011 Posted July 11, 2011 I had much better luck with this propellant using KClO3 as opposed to KClO4, as taboo as that is. Flew well, looked pretty, pressed nice, and dirt (asphalt?) cheap. Was oddly sensitive to shock though, anybody know the sulfur content of asphalt is?
dagabu Posted July 11, 2011 Author Posted July 11, 2011 I only own 8 oz of Chlorate and that is for e-matches only. -dag
Mumbles Posted July 11, 2011 Posted July 11, 2011 I honestly haven't a clue on the sulfur content of asphalt, but it's clearly not negligible. Anyone near road construction can tell you that. Intuition tells me that it is probably higher than the content of lighter fractions. A quick google search shows values somewhere between 2 and 5% sulfur (or at least sulfur containing compounds) by mass. Low melting point probably plays a role in sensitivity too.
superstring Posted July 17, 2011 Posted July 17, 2011 JATO is an acronym. It means JUST ABOUT TOOK OFF
moondogman Posted August 14, 2011 Posted August 14, 2011 4% potassium benzoate made all the difference it flew great with a whistle boost.Steve
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