NightHawkInLight Posted December 5, 2011 Posted December 5, 2011 Deal with it over PM guys. This has gotten way off topic and rather annoying to have to scroll through.
stckmndn Posted December 5, 2011 Posted December 5, 2011 Well I never got an answer to my question. See what you started JFeve?
nater Posted December 5, 2011 Posted December 5, 2011 Well I never got an answer to my question. See what you started JFeve? Your question about if you can mix different fuel and nozzle or nozzleless combinations until you CATO? Why not? When I was having trouble with my slow fuel at Tri State, Algenco and the others that were in the manufacturing area, first suggested pressing an increment or 2 of whistle mix, then finishing the rest of the core with my sluggish BP mix. It is the same premise that Steve LaDuke suggests in his video about Hybrid BP Rockets. I ended up milling some new fuel and tried different spindles and nozzle / nozzless configurations with a handful of different BP fuels on hand. Moondogman gave me some his hottest BP that had a CATO in a nozzleless configuration! At the end of the weekend, I had rockets fail to launch, fly 50 ft or so, have great flights, and CATO's. I'm still dialing in my fuel, my techniques, and my tooling, but there is no reason you can't experiment with compatible fuels. I always shoot at club events, so just be prepared to warn people on the line what you have. Since you've said you have open desert where you can shoot alone this might not be a problem.
stckmndn Posted December 5, 2011 Posted December 5, 2011 Well actually my question was more about the strength of the tubes. The tubes can only take so much pressure before they blow. So regardless of which combination of fuel and clay one uses the tubes will fail at their failure limit. So in essence aren't the nozzled rockets and the nozzleless ones really failing at exactly the same point? Are they producing the same level of pressure / thrust at CATO?
nater Posted December 5, 2011 Posted December 5, 2011 That's a good question, my GUESS would be that you are correct, the tubes have a certain point of failure and they will fail whenever the pressure exceeds that limit. I am also GUESSING that it is easier for a nozzled design to get the higher pressures quicker and more likely to CATO than nozzleless. My nozzleless CATO at Tri-State surprised everyone there, unfortunately there's no way of knowing if the failure was due to a crack in the fuel grain when I rammed it, or if the fuel was too hot for the tube. Have you been following the various threads on thrust test stands on Passfire? Ned, Dan C, and Lloyd S have been posting some great information comparing nozzle and nozzleless BP motors on standard and U/H spindles. They're getting data that cannot be disputed by looking at thrust curves.
stckmndn Posted December 5, 2011 Posted December 5, 2011 That's a good question, my GUESS would be that you are correct, the tubes have a certain point of failure and they will fail whenever the pressure exceeds that limit. I am also GUESSING that it is easier for a nozzled design to get the higher pressures quicker and more likely to CATO than nozzleless. My nozzleless CATO at Tri-State surprised everyone there, unfortunately there's no way of knowing if the failure was due to a crack in the fuel grain when I rammed it, or if the fuel was too hot for the tube. Have you been following the various threads on thrust test stands on Passfire? Ned, Dan C, and Lloyd S have been posting some great information comparing nozzle and nozzleless BP motors on standard and U/H spindles. They're getting data that cannot be disputed by looking at thrust curves. Actually I hadn't been following those but I will now. Just my own observations from testing so far. From what I've seen the nozzleless are more forgiving most likely for the reason you give. But it's kind of weird to me to have a rocket without a choke. Anyway these were just experiments to see how heavy a header we could lift. For usual purposes this isn't the goal. I'd like a nice smooth flight and a beautiful tail. Thanks for your answer.
Mumbles Posted December 5, 2011 Posted December 5, 2011 Black powder has a pressure dependent burn rate. It could just be that a nozzled rocket is easier to allow that pressure to "run away". The nozzle gives some resistance, so there will be a higher pressure on the interior than what is exiting. A nozzless rocket may allow a higher thrust as there is no resistance as the hot gas exits, where as with a nozzle that pressure would cause it to run away and CATO.
guntoteninfadel Posted December 5, 2011 Posted December 5, 2011 Stk.... Quit screwing with him as I am sure he is but one or maybe two post from abomination. I as well as others appreciate your post. Just keep that I'n mind.
JFeve81 Posted December 5, 2011 Author Posted December 5, 2011 Wooh! That was a lot of stuff to scroll through. Thanks for those that actually replied on topic. So from these replies I'm assuming that most rocket makers use the traditional cored design? I guess since I have my little 2oz rockets flying pretty consistantly, and I have a crap load of tubes in that size, I can do some testing. Either way let's keep the topic going ON TOPIC. I'm finding there is alot of different variables to consider when rocket making.
allrocketspsl Posted December 5, 2011 Posted December 5, 2011 Wooh! That was a lot of stuff to scroll through. Thanks for those that actually replied on topic. So from these replies I'm assuming that most rocket makers use the traditional cored design? I guess since I have my little 2oz rockets flying pretty consistantly, and I have a crap load of tubes in that size, I can do some testing. Either way let's keep the topic going ON TOPIC. I'm finding there is alot of different variables to consider when rocket making. wrong like in anything the harder it is to get right is never the most popular,endburners are by far more popular then nozzeless,just not maybe here but it is industry wide.
firebird Posted December 5, 2011 Posted December 5, 2011 wrong like in anything the harder it is to get right is never the most popular,endburners are by far more popular then nozzeless,just not maybe here but it is industry wide. The 3 different rockets all have their place End burner's are alot of fun Personally I run a mix of whistle fuel in them or straight whistle fuel depending on how I want them to perform. The length of the tube is only relevant to how far or long you want them to burn but keep in mind the more fuel you stack on there the less load carrying ability you will have and yes they are the least when it comes to pack mule ability .With a little testing and knowledge they can carry a payload to a hell of a height.Have you ever seen one of LaDukes fly to 3000 plus ft and still have a hell of a boom? Core burners ,standard bp or super bp all can be hand pounded as can any non impact sensitive fuel contrary to the beliefs of some. This tooling has a little longer spindle then U/T but is much less versatile. There are so many variables here Coal type, mill time , PSI on the comp, are your chems prepped correctly? Yes they make great rockets and have good lifting power they have a nice tail but they have never been my cup of tea.Nozzle less , while you can make these using regular BP tooling the performance will suffer they can handle a longer core there by consuming more fuel and making power as the fuel is being consumed the rocket is just getting more and more powerful .They have a beautiful tail and a awesome sound very distinct to them on take off. It is all about gas production the longer the core you can burn at once the more gas is made and expelled I am sure this is not scale-able but for what we do it works. Why does a whistle rocket make so much thrust with out a nozzle ? Gas production. Motor tubes well doesn't that just depend on who's tubes you are using ? NEPT have the highest burst of a production tube. But as for strength you have to look at more then that. You have to consider the surface area you are spreading that force over the speed of the fuel your burning how hard is the grain you have pressed into the case and how much is it helping to add strength to the tube before it quits helping then how much presure is being built . I have even combined the 2 before . Taken a core burner made it a whistle all the way up to the last little bit of the spindle then made a end burner choke on the top of the spindle then end burner on top.
allrocketspsl Posted December 5, 2011 Posted December 5, 2011 (edited) The 3 different rockets all have their place End burner's are alot of fun Personally I run a mix of whistle fuel in them or straight whistle fuel depending on how I want them to perform. The length of the tube is only relevant to how far or long you want them to burn but keep in mind the more fuel you stack on there the less load carrying ability you will have and yes they are the least when it comes to pack mule ability .With a little testing and knowledge they can carry a payload to a hell of a height.Have you ever seen one of LaDukes fly to 3000 plus ft and still have a hell of a boom? Core burners ,standard bp or super bp all can be hand pounded as can any non impact sensitive fuel contrary to the beliefs of some. This tooling has a little longer spindle then U/T but is much less versatile. There are so many variables here Coal type, mill time , PSI on the comp, are your chems prepped correctly? Yes they make great rockets and have good lifting power they have a nice tail but they have never been my cup of tea.Nozzle less , while you can make these using regular BP tooling the performance will suffer they can handle a longer core there by consuming more fuel and making power as the fuel is being consumed the rocket is just getting more and more powerful .They have a beautiful tail and a awesome sound very distinct to them on take off. It is all about gas production the longer the core you can burn at once the more gas is made and expelled I am sure this is not scale-able but for what we do it works. Why does a whistle rocket make so much thrust with out a nozzle ? Gas production. Motor tubes well doesn't that just depend on who's tubes you are using ? NEPT have the highest burst of a production tube. But as for strength you have to look at more then that. You have to consider the surface area you are spreading that force over the speed of the fuel your burning how hard is the grain you have pressed into the case and how much is it helping to add strength to the tube before it quits helping then how much presure is being built . I have even combined the 2 before . Taken a core burner made it a whistle all the way up to the last little bit of the spindle then made a end burner choke on the top of the spindle then end burner on top. i roll my tubes to fit the comp,that way i can control weight and put as much in the shell as possible.I roll heavy or slim depending on the static test.If the choke and nozzel hold and the tube fails I roll a thicker tube,really very simple Edited December 5, 2011 by allrocketspsl
stckmndn Posted December 5, 2011 Posted December 5, 2011 (edited) If I could only have one set of rocket tooling it would be a traditional core burner. I never get tired of watching these take off. They have a great roar, a beautiful tail, and the lifting power to carry most any header you are likely to make for it. Altering the tail to your liking is easy as pie. You can pound them up without a nozzle (using hotter fuel) and they work great. They're just a very fun and versatile design. You've probably seen this site, no doubt, but it shows the different rocket types available. Firesmith Tooling If you do choose to buy tooling make sure it uses NEPT tubes. That's New England Paper Tubes available at HobbyHorse. They are hands down the best tubes available. Edited December 5, 2011 by stckmndn
firebird Posted December 5, 2011 Posted December 5, 2011 Since the ID measure on all tooling is a standard unit of measure where would a guy find a set of tooling that NEPtT does not fit ? I have checked all the us sites of the toolMakers and just can't find any.
stckmndn Posted December 5, 2011 Posted December 5, 2011 I have found that the Firefox and Skylighter tubes are too big for my Wolter and Firesmith tooling.
dagabu Posted December 5, 2011 Posted December 5, 2011 Lets take this even further: Paper tube strength will vary from tube to tube, ramming to pressing, dwelling on pressure to static dump (slow motion ramming where the pressure on an electric press is applied and revived with no dwell time), temperature, humidity, support strength and fit. I have seen hand rammed 3# rockets fly consistently with tight chokes and long spindles and have seen many machine pressed rockets with large chokes and shorter spindles pop on the rack, each using the same black powder and NEPT tubes. The rockets that popped were made in advance and rested for 3 months, they were machine made, all pressed to exactly the same pressure, good bulkheads and nozzles. Why did they pop? In this case, the fuel must have cracked while resting since another identical rocket was made at PGI and shot that same day successfully. It has also been my experiences that the mushy chipboard tubes can be pressed in ill fitting supports and be over-pressed with less risk of CATO then NEPT tubes though I have heard the opposite as well from others. Also, consider the way a motor is lit. If lit way up in the end of the fuel grain, the fuel will burn in a cone shape (upside-down tear drop) causing two nozzles to choke the fuel while the fuel burns off. Consider that you don't use any clay, just a nozzleless motor that is lit at the top. The thrust spike will be very close to the same as in a nozzled rocket but will fall off quickly as the "nozzle" of fuel opens up. If lit at the end of the fuel grain, the nozzleless will be sluggish with most fuels (not hot BP or whistle) but the nozzled BP motor will show a slower lift off but the overall burn time and usable thrust will be very close to the same. Now, all of this is IME and I have to finish my load cell to back this up but in speaking with others, there is agreement that something close if not the same, is happening within these rocket motors. Time will tell. -dag
firebird Posted December 5, 2011 Posted December 5, 2011 Not what I said at all. A good tube maker nept and a good tooling maker use a true I'd measure and a true od measure on their tools. I can see your trying to twist the info around to attempt to make your self look smart. I just put a gauge to some old skylighter tooling. Right on.
allrocketspsl Posted December 5, 2011 Posted December 5, 2011 that about sumes it up,one thought I use the food saver for motors and in florida I can ram summer or winter with same results once I have got the tube and comp where i want it ,its a matter of firing it up.IMPORTANT: since I have no ball mill I have to top core fuse all mine or they just wont perform!Ask a hundred rocketeers one question and get a hundred different answeres!
dagabu Posted December 5, 2011 Posted December 5, 2011 Ask a hundred rocketeers one question and get a hundred different answeres! No doubt! Side note: I just shot a whistle rocket off that I made three years ago and lost (rolled behind a cabinet). It had signs of mold on the bottom of the tube and the whistle in the end was crumbly but being the trooper I am (or fool, you chose) I took it to the fall shoot and launched it. I'll be darned, it worked just fine. Go figure! -dag
stckmndn Posted December 5, 2011 Posted December 5, 2011 Not what I said at all. A good tube maker nept and a good tooling maker use a true I'd measure and a true od measure on their tools. I can see your trying to twist the info around to attempt to make your self look smart. I just put a gauge to some old skylighter tooling. Right on. That's my personal experience. I've got two boxes of unusable tubes to prove my personal experience. YMMV. Go fly some rockets and get off my back.
Eric70 Posted December 5, 2011 Posted December 5, 2011 Looks like I am not missing much here. Back into the shadows I go.
allrocketspsl Posted December 5, 2011 Posted December 5, 2011 No doubt! Side note: I just shot a whistle rocket off that I made three years ago and lost (rolled behind a cabinet). It had signs of mold on the bottom of the tube and the whistle in the end was crumbly but being the trooper I am (or fool, you chose) I took it to the fall shoot and launched it. I'll be darned, it worked just fine. Go figure! -dag I here ya,whats the other guy mean by saying to look smart by twisting the tooling or such i missed it? Looks like I am not missing much here. Back into the shadows I go. hum who are you mate?
dagabu Posted December 5, 2011 Posted December 5, 2011 I've got two boxes of unusable tubes to prove my personal experience. No such thing I would be glad to take such naughty tubes off your hands if you would like. -dag
dagabu Posted December 5, 2011 Posted December 5, 2011 Looks like I am not missing much here. Back into the shadows I go. There is plenty good stuff mixed in with the chaff, just have to read through it all. -dag
firebird Posted December 5, 2011 Posted December 5, 2011 I here ya,whats the other guy mean by saying to look smart by twisting the tooling or such i missed it? Stick had said that to make sure you get your tooling to fit NEPT tubes . When I drew attention to the fact that any tool maker worth his salt makes them all to a standard size he tried to draw the focus off what he said and turn it to his vast experience led him to getting tubes from SL and FF that did not fit his tooling. I pointed out that he was twisting around what he said to make himself look correct in the conversation when in fact he had said two completely different things. Look back at the last 2 pages it is not too hard to see. He wants to bitch about me not answering any questions when in fact he has not answered even one of mine . Although I have got a few cool new names from him. It's a 3rd grade mentality . when you can't answer the questions you call names (Stalker ,buttercup I may have missed one) then when you are further called out he now wants me to get off his back. It is laughable really. If you really want to see what a up standing person he is get a guest sub to passfire and read some of his finer works . I won't pollute this thread any further it would be better to just expose him in a new thread. hum who are you mate?
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