NightHawkInLight Posted March 29, 2011 Author Posted March 29, 2011 Thanks NHIL, it sure will pop off the spindle if you brighten it up some more. I really like your idea for removal, I am going to try an all aluminum design, can you spare some details? I'm not too sure how to explain better than the pictures but I'll give it a shot. The bottom layer of oak is solid. The second has one hole drilled in the center for the bottom of the spindle to sit in. Those two blocks are then screwed together leaving the smooth portion of the screw sticking out of the top with the heads cut off. This makes pins which align the top block in the same position consistently. When done ramming a rocket, the top block is removed from the bottom two. The rocket, which will come off with the top block, can be easily removed by twisting the two nuts in opposite directions. This widens the gap between them, eventually pulling the spindle through the bottom of the block of wood and removing it from the rocket.
dagabu Posted March 29, 2011 Posted March 29, 2011 I'm not too sure how to explain better than the pictures but I'll give it a shot. The bottom layer of oak is solid. The second has one hole drilled in the center for the bottom of the spindle to sit in. Those two blocks are then screwed together leaving the smooth portion of the screw sticking out of the top with the heads cut off. This makes pins which align the top block in the same position consistently. When done ramming a rocket, the top block is removed from the bottom two. The rocket, which will come off with the top block, can be easily removed by twisting the two nuts in opposite directions. This widens the gap between them, eventually pulling the spindle through the bottom of the block of wood and removing it from the rocket. PERFECT!!! I got it. Now, lets see If I can reproduce it in aluminum.
NightHawkInLight Posted March 29, 2011 Author Posted March 29, 2011 PERFECT!!! I got it. Now, lets see If I can reproduce it in aluminum. Excellent. Glad I could help. Well, here are the first two rockets fired off my new spindle: Have you ever seen anything in pyro go so well the first time?
dagabu Posted March 29, 2011 Posted March 29, 2011 LOL! No, not really. Good job on those, you really have a great idea there.
Bilbobaker Posted April 7, 2011 Posted April 7, 2011 I got all my components to build one out of brass and aluminum, thanks for the pictures, and video.
NightHawkInLight Posted April 7, 2011 Author Posted April 7, 2011 I got all my components to build one out of brass and aluminum, thanks for the pictures, and video. Great, let me know how it goes. This video's a little nicer if you haven't seen it: http://www.youtube.com/watch?v=zE1UwqD9W6g
WonderBoy Posted April 7, 2011 Posted April 7, 2011 Dag, have you had a chance to try making that yet? I use a similar method using SS and aluminum. If I get a chance to press up a motor this weekend I'll video my removal method.
dagabu Posted April 7, 2011 Posted April 7, 2011 (edited) Naw, with spring coming on hard, the wife has me cleaning... I would love to see all of your methods for removal, I have an idea about how to do it but the machining may be beyond me. Edited April 7, 2011 by dagabu
Mumbles Posted April 8, 2011 Posted April 8, 2011 The prototypes I've seen have the spindle screw directly into the base. Then the threads and a stack of washers are enough to coax the spindle out. Most spindles have a greater taper than what NHIL put on his, so once you get them popped out a little they tend to slide right out. At least this is how I've seen them done with taper pins as spindles.
WSM Posted April 8, 2011 Posted April 8, 2011 If I may add to your sentiment Mum, thrust curves show a significant advantage to having a divergence that keeps with the de Laval concept. The extra tube caries on the phenomenon further down the thrust stream and captures lost thrust redirecting it to carry the motor further. At least in theory A de Laval nozzle (or convergent-divergent nozzle, CD nozzle or con-di nozzle) is a tube that is pinched in the middle, making a carefully balanced, asymmetric hourglass-shape. It is used to accelerate a hot, pressurised gas passing through it to a supersonic speed, and upon expansion, to shape the exhaust flow so that the heat energy propelling the flow is maximally converted into directed kinetic energy. Because of this, the nozzle is widely used in some types of steam turbine, it is an essential part of the modern rocket engine, and it also sees use in supersonic jet engines.-Wikkipedia Hi dagabu, Unless I missed it in the quote above, once the gasses reach supersonic speed (hopefully at the narrowest point of the nozzle), they continue to accelerate in the divergent section (if I remember correctly). Hence the mach diamonds viewed in clear photos of properly burning rocket engines, if I'm correct . WSM
dagabu Posted April 8, 2011 Posted April 8, 2011 True..... The only problem is that I dont know if pyro (maybe whistle) fuels reach supersonic speed to take advantage of the phenomenon. I see only small changes between my optimized Laval set and the universal set.
WonderBoy Posted April 10, 2011 Posted April 10, 2011 Here ya go Dag. The spindle is a SS cap screw, which is mounted into a threaded aluminum shoulder, which is then mounted in a firesmith base. The washers and nut are all SS. MVI_0842.AVI Compressed version: MVI_0842.wmv
dagabu Posted April 10, 2011 Posted April 10, 2011 (edited) Here ya go Dag. The spindle is a SS cap screw, which is mounted into a threaded aluminum shoulder, which is then mounted in a firesmith base. The washers and nut are all SS. Nice job! I like how you used Bens base too. I made a tooling set to test out the Laval Nozzle design, I have an identical set that has the standard 30% convergence-divergence to test it against as well. http://www.pyrobin.com/files/101_2093.jpg http://www.pyrobin.com/files/101_2092.jpg Edited April 10, 2011 by dagabu
dagabu Posted April 10, 2011 Posted April 10, 2011 Its just for testing but I will sell it if you are looking.
Bilbobaker Posted April 10, 2011 Posted April 10, 2011 Its just for testing but I will sell it if you are looking. How much?
dagabu Posted April 10, 2011 Posted April 10, 2011 It took forever to make the curves match the math for the Laval Nozzle set, all brass spindle 2.7" long and base permanently mounted. 8" aluminum rammer with Laval tip (for pressing the nozzle only), 6" flat rammer with hole for spindle and 4" flat rammer. $100.00 delivered to the lower 48. I still need it for three weeks until I have the testing all done. It will be delivered in like new condition, all shiny.
Bilbobaker Posted April 11, 2011 Posted April 11, 2011 (edited) How much? Great price for such nice machine work. I'd like to see the test results first.Right now I'm finishing up on the plans video posted by Nighthawkinlight and tumbling some rocket fuel in the ball mill. http://www.grassrootsdiy.com/ Edited April 11, 2011 by Bilbobaker
NightHawkInLight Posted April 11, 2011 Author Posted April 11, 2011 Great price for such nice machine work. I'd like to see the test results first.Right now I'm finishing up on the plans video posted by Nighthawkinlight and tumbling some rocket fuel in the ball mill. http://www.grassrootsdiy.com/ Ha, thanks for the advertising. Let me know how it turns out.
Bilbobaker Posted April 11, 2011 Posted April 11, 2011 Ha, thanks for the advertising. Let me know how it turns out. I'm pretty sure it will turn out some nice night sky ambiance real soon now. ♥
allrocketspsl Posted July 21, 2011 Posted July 21, 2011 my suggestion for NHIL is not to make any tooling for the YT people,they will be safer if they spend a buck or two and get it right
MrB Posted August 16, 2011 Posted August 16, 2011 Naw, with spring coming on hard, the wife has me cleaning...At this point i sure hope the wife has let you quit spring cleaning. How did things work out with the "other" nozzle design? Amazing finish on your stuff, if i ever decide to go with rockets, i'll line up and see if your interested in making a set... You have an amazing attention to details.B!
dagabu Posted August 16, 2011 Posted August 16, 2011 At this point i sure hope the wife has let you quit spring cleaning. How did things work out with the "other" nozzle design? Amazing finish on your stuff, if i ever decide to go with rockets, i'll line up and see if your interested in making a set... You have an amazing attention to details.B! I am WAY beyond that but my load cell has sat dormant all summer and I will likely not get it done before winter and then I will graph out the nozzle designs. It will be a while before I let this one go. -dag
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