TheArchitect23 Posted November 3, 2012 Share Posted November 3, 2012 (edited) tooling like this? just need to make 1 more rammer, and i can test. finish is not important at this stage, Edited November 3, 2012 by TheArchitect23 Link to comment Share on other sites More sharing options...
usapyro Posted November 3, 2012 Author Share Posted November 3, 2012 Your tooling confuses me... This is my current process... http://i50.tinypic.com/66hkt4.jpg I figure the tooling would be the same! Except it would be... Ram plug, increment, then drill... Link to comment Share on other sites More sharing options...
dagabu Posted November 3, 2012 Share Posted November 3, 2012 tooling like this? just need to make 1 more rammer, and i can test. finish is not important at this stage, Yes, that would work but there would be no need for a rammer with a hole, just the pointed one and then the flat rammer. USA, I do understand why you drill out the center but in my experience with nozzles and nozzle clay, I find alignment, radial cracking and uneven surfaces to be real problems. If I were to make tooling for this setup, I would use the flat rammer to press the bottom clay plug up to the point where the hollow begins and then use my pointed rammer to ram the shaped clay portion of the clay. I would then go back to the flat rammer to press in the fuel. As a mechanic, I hate the idea of taking a drill bit and suining it in clay. -dag Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 3, 2012 Share Posted November 3, 2012 USA pyro, I think your a little confused about rocket stability. In a stick stabalized rocket you typically use your stick to bring the Cg back below the nozzel--but in reality the goal is to being the Cp below the Cg. The rocket is a weight at the head with little pressure (due to the low surface area), and the stick has considerable pressure (and drag), but little weight. Having the Cg lower reduces stability--but it ends up being a concequence of lowering Cp in a stick or fin stabalized rocket. In a fin stabalized rocket the fins act as the stick does, to lower Cp, they have less weight then a stick alot of the time and as such offer a superior rocket with less weight that is still stable. Lowering the fin alignment helps to lower the Cp (quite a bit), NOT the Cg, it does lower the Cg slightly, but that is a negitive consceqence of lowering their alignment. Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 3, 2012 Share Posted November 3, 2012 TheArchitect23, how do you plan on drilling the vent hole? Link to comment Share on other sites More sharing options...
TheArchitect23 Posted November 3, 2012 Share Posted November 3, 2012 (edited) the spindle is "upsidedown and backwards"the 1 longer rammer is for the clay plug. it is opposite of the spindle.you ram clay in 2-3 increments ( i will probably press ) then use the flat rammer to top off the top flat.remove the rocket. turn upside down and start ramming delay, then fast BP than BP + SF until 8-10 mm from the top ( bottom )ram clay plug or report chamber. cap. the drill fixture i havent finished yet, just got he tailstock fixed on my lathe so i need to make the drill template and last flat rammer.the drill fixture will be like a stinger fixture. L angle aluminum with multiple brass lined angled guides for assorted tube sizes.more pix to come. once finished i will dig out the camera and do a tutorial or something Edited November 3, 2012 by TheArchitect23 Link to comment Share on other sites More sharing options...
usapyro Posted November 3, 2012 Author Share Posted November 3, 2012 (edited) Ah... I get it... Upside down, then right side up for the increments... Interesting! Btw, to those doing tooling... You might want to try an internal channel that is 60-70% of the I.D. width and compare it to the 50%. Your going to start losing efficiency in steering the gas, but that might be necessary to get rough metals out of the device through the centrifugal force. It lowers the slope the particles need to climb a lot. This firework is a tricky balancing act... You need enough centrifugal force for stability, but not so much that it traps sparks. You can increase the width of the internal channel and lower the choke slope angle to make things easier for the flow of sparks, but then you start losing nozzle efficiency in steering gas downward with the lower vent nozzle length. I'm going to machine another dowel with this slope instead of my rounded dowel and see if I can get 100% of the charcoal sparks coming out. If your not concerned with adding effects to the fuel... Don't worry about this! This is the ultimate design right here... Needs some good tooling!http://i47.tinypic.com/zsn2ae.jpg Edited November 3, 2012 by usapyro Link to comment Share on other sites More sharing options...
usapyro Posted November 3, 2012 Author Share Posted November 3, 2012 (edited) Machined my new low angle cone shaped dowel with a flat front the size of my drill bit today... I will be able to replicate the optimal designs perfectly now! I am in a better mood today after my carefully built launcher wasn't as accurate as hoped... I am going to make another set of improvised drill guide tooling to test this design for someone in here who was interested in getting real height... My guess will be that lowering the angles down about like this below my current forty five will double the firework's vertical. The most I could get running 100% BP/SF 50:50 was around 125-150' with approx 45 degree nozzles and a 2.5" effective fuel grain. It doesn't take much angle change to drastically effect the speed. I'm going to drill up from the lowest angle possible for the length of the internal choke nozzle. Might lengthen the internal nozzle a little! Clay weight increases fast though... The vent nozzle offset will be increased around 1.5mm on each side to adjust for the loss of rotation thrust on the increased angles. So, around a 4.5mm offset per side should be stable. Even if your not looking for vertical... This should fly with slower fuel's or slower fuel ratios!http://i49.tinypic.com/2uypw6p.jpg This below is not recommended... It has to be drilled perfectly! I have been thinking for a few minutes, and I am actually going to do this... This is real tricky, because of the high vent nozzle offset I will use only somewhere around 30-50% of the drill bit will actually intersect the fuel grain. Plenty for gas flow though because the intersection is oval shaped. Don't worry if the distance between the vents and the clay plug looks thin in the choke... Those small round vents don't collapse easy! They also don't erode much either... If they erode it's mostly on the top side for obvious reasons...http://i48.tinypic.com/apej61.jpgMight take me a couple tries with drilling this one! Edited November 3, 2012 by usapyro Link to comment Share on other sites More sharing options...
usapyro Posted November 4, 2012 Author Share Posted November 4, 2012 (edited) Ok, here is the video for the steeper angle vent nozzles... Version 2. Very nice height for having a vent nozzle rupture with still a little over two seconds of burn left. There was no delay before the report. Just a quarter inch of BP/SF in a hole through the bulkhead. I noticed I had some of my choke nozzle cracked and missing before I put in the fuel increments, but it launched fine anyway! The delay had FeTi. Power grain was 50:50 BP/SF with a 2g report in the bulkhead. There was a teaspoon of hot BP meal between the delay and fuel grain. I'm going to make these things six inches long from now on and use a angle around 55-60 degrees down. This angle was a pain in the neck to drill! The longer they are the more stable the launch is. If your making your own tooling I would recommend starting out with the easy type. High offset... 4-6mm per side. 45 degree angle... Before messing around with these high vertical type. The BP/SF 50:50 fuel grain was only 2.10 inches long. I lengthened the plug to get that angle to work. Ok, now I'm done unless anyone has any requests? Only playing with these around the 4th of July and other holidays. http://www.youtube.com/watch?v=9C4Du0QyNi0A ground show and a sky show all in one firework! Hmmm... Probably could have a longer ground show to warm up the nozzles! The angle used is the one on the left...http://i46.tinypic.com/dpbwb7.jpg Quick note on length... I'm not sure why TheArchitect made his tooling for a four inch device... Since I am done with testing I am going to be making them around six inches. Double the fuel grain with not much more weight... And more stability at launch! Edited November 4, 2012 by usapyro Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 4, 2012 Share Posted November 4, 2012 That one looks real nice. Have you tried the divergence yet? I'll be back home tomorrow, but probably wont be able to build my first one of these til Wednesday--I have alot of catching up to do inside and outside of pyro. Link to comment Share on other sites More sharing options...
usapyro Posted November 4, 2012 Author Share Posted November 4, 2012 (edited) Ergh... Trying to drill a nozzle in the side of a paper tube with a cement drill bit(Not sure what these V bits are normally for)... = A mess... It probably also reduces performance because the gasses need that vent nozzle length to be steered in the proper direction. End up with more gas going sideways! These things make a pretty decent stick and fin free rocket with those steep angled nozzles! I just keep watching that video over and over... Such a BEAUTIFUL smooth takeoff... Wow... Edited November 4, 2012 by usapyro Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 4, 2012 Share Posted November 4, 2012 Yeah, I thought about the uneven divergence problem, I cant say Ive fully solved it. I dont think I have the proper bit for it to try, I might go out and buy one. Link to comment Share on other sites More sharing options...
usapyro Posted November 4, 2012 Author Share Posted November 4, 2012 (edited) Certain rockets I recall from movies that were positioned upon the sides of a rocket... They had a device to steer the gasses downward. Think of a cone split in half and positioned over the hole. I was thinking of making a couple clay tubes drilled out, plugged in one end and fastening it to the side somehow... Sealing it to the rocket with water glass/epoxy. Small wires around the rocket or maybe just tape? It's too complex to be practical though! It would also burn up the entire side of the rocket! Yeah, I thought about the uneven divergence problem, I cant say Ive fully solved it. I dont think I have the proper bit for it to try, I might go out and buy one. Edited November 4, 2012 by usapyro Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 4, 2012 Share Posted November 4, 2012 Indeed, it is to complex for practicality--its too bad too. Hmm... Oh well. Ive decided I'm not going to try to lift shells with these, I'm going to try the flaps, then have a descending waterfall. Its cooler because I cant do it with much else. And it will be really beautiful. Link to comment Share on other sites More sharing options...
usapyro Posted November 4, 2012 Author Share Posted November 4, 2012 Ah, your going to launch it up fast, then slow it down while having a waterfall? I have a new helicopter design I am going to test soon. Got it drawn up. Just kinda lazy today... Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 4, 2012 Share Posted November 4, 2012 No, after burnout Im going to have a waterfall come out of the bottom where I would normally put my end effect, while it helicopters down. Like a flare on a parachute. It might not work though, it would need to have a long fall time. Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 4, 2012 Share Posted November 4, 2012 I wish I could show you a picture of what I'm thinking. Link to comment Share on other sites More sharing options...
usapyro Posted November 4, 2012 Author Share Posted November 4, 2012 Waterfall parachute... I get it! What you could do is have one of these with fold down propellers strapped to the side. At the end quickmatch blows the tape holding them folded and they fold up for a slow fall! Not actually that hard to do I don't think. Just need two wooden hinges... See how this works? They fold up to a point and are blocked. They are held to the thing with wraps of sticky match.http://i48.tinypic.com/2je9wxw.jpg Probably simpler to build a parachute for the waterfall! Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 4, 2012 Share Posted November 4, 2012 Would be simpliler to build a parachute--but the rising effect would be different. And its its fun and educational to try new things Link to comment Share on other sites More sharing options...
FrankRizzo Posted November 6, 2012 Share Posted November 6, 2012 (edited) I think FrankRizzo is talking about a stinger. Just doesnt know the name. Correct me if I'm wrong. The device I'm describing could be made on a stinger spindle, but the vent is not drilled tangential to the wall of tube like a stinger would be. Instead, the vent is simply drilled perpendicular to the tube (near the nozzle) like a normal spinner (ground bloom flower, or buzz bomb, for example). Unlike a stinger which needs to be launched from a nail, this type is simply fused in the vent hole, then launched from the ground like a buzz bomb with no wings. Edited November 6, 2012 by FrankRizzo Link to comment Share on other sites More sharing options...
AirCowPeacock Posted November 6, 2012 Share Posted November 6, 2012 I see. Link to comment Share on other sites More sharing options...
zAZO9a Posted July 31, 2013 Share Posted July 31, 2013 cant wait ta try this Link to comment Share on other sites More sharing options...
BlueComet24 Posted December 17, 2015 Share Posted December 17, 2015 I have an idea: How about putting a shell on the bottom of the flying fountain? That way it would really look like a backward rocket (except that there's no stick). You'd have to use a cylinder shell or glue a disk to the bottom of a ball shell so that it has a flat bottom to spin on just before liftoff. I'm not sure how stable it would be, so I would certainly not recommend putting a salute on one (at least until after much testing has been done), but it sounds like the flying fountains were very stable due to their high rotation speed. The shell might actually make them more stable, because it would lower the center of gravity, acting like a guide stick on a normal rocket. Link to comment Share on other sites More sharing options...
OldMarine Posted December 18, 2015 Share Posted December 18, 2015 Video? Link to comment Share on other sites More sharing options...
BlueComet24 Posted December 18, 2015 Share Posted December 18, 2015 I haven't made this device (yet), I'm just proposing an idea. It would look something like this:http://i.imgur.com/nBaH4sm.jpg Link to comment Share on other sites More sharing options...
Recommended Posts