dagabu Posted April 14, 2011 Share Posted April 14, 2011 Yup, BOOM! Leave the nozzle clay out and see what you think. BP rockets with a nozzle use pretty tame BP, hot BP just CATOs. Link to comment Share on other sites More sharing options...
ballmill Posted April 15, 2011 Author Share Posted April 15, 2011 Guys, since I'm using straight bentonite clay for my nozzle material without wax is it safe for me to make these and store them in a cooler with a large bag of silica gel for a few months? I picked up 9 lbs of silica at harbor freight for around $3.00 Link to comment Share on other sites More sharing options...
ballmill Posted April 17, 2011 Author Share Posted April 17, 2011 Dagabu, I fired a rocket today with hot willow 75/15/10 WITH a nozzle, propellant lit right on the end, and it flew GREAT! Very straight flight and made a nice whooosh. Link to comment Share on other sites More sharing options...
dagabu Posted April 17, 2011 Share Posted April 17, 2011 Isn't that just the best sound in the world? Congratulations on your rocket! Link to comment Share on other sites More sharing options...
ballmill Posted April 17, 2011 Author Share Posted April 17, 2011 Indeed it is. I also fired my first nozzleless today with good flight, however I was expecting a faster takeoff. I don't think it would have lifted a 4" shell. This was rammed using my hot willow meal on my core burner BP spindle 3/8" diameter opening at the bottom. Will I get more power if I try and ramp up my BP and ram it on a SMALLER diameter rod, such as 3/16"? I better remember to bring my camera for the next test flights... Link to comment Share on other sites More sharing options...
dagabu Posted April 17, 2011 Share Posted April 17, 2011 I will post the links to some side by side tests of spindle diameters. The findings were that in nozzleless rockets, the smaller the nozzle the slower the rise. With a nozzle, it would be quite different, the choke will increase the thrust but with a nozzleless, the thrust is reduced because the surface burning is reduced. The second part is the hot fuel, if you augument the fuel with whistle (25% - 50%) you will boost the thrust and get a faster take off. Link to comment Share on other sites More sharing options...
ballmill Posted April 18, 2011 Author Share Posted April 18, 2011 Well that explains why my rocket lacked a bit of power. my spindle diameter at the base was 3/8". Got any info on storing rocket motors with bentonite clay nozzles? I was thinking a cooler with racks and a bag of silica. For nozzleless it's not an issue, but I heard the clay nozzles tend to warp. Link to comment Share on other sites More sharing options...
dagabu Posted April 18, 2011 Share Posted April 18, 2011 Well that explains why my rocket lacked a bit of power. my spindle diameter at the base was 3/8". Got any info on storing rocket motors with bentonite clay nozzles? I was thinking a cooler with racks and a bag of silica. For nozzleless it's not an issue, but I heard the clay nozzles tend to warp. We are having some round table conversation on the nozzleless rockets and the phenomenon of diminishing thrust over on Passfire so the question of spindle size has jet to be fully answered. I will let you know what the end decision is. I wont store my clay nozzled rockets any differently then i store my nozzleless, I just make sure I have a reamer with me so that I can check and open the throat if necessary. I check the nozzle before sticking them. Link to comment Share on other sites More sharing options...
ballmill Posted April 18, 2011 Author Share Posted April 18, 2011 I started that thread, the pros took it from there Link to comment Share on other sites More sharing options...
jimbo Posted April 18, 2011 Share Posted April 18, 2011 when fusing nozzle-less rockets do you guys quickmatch to the top of the core or just hook plain visco fuse up into the core,I'm a bit worried that my fuel will be to hot to quickmatch the top of the core. Link to comment Share on other sites More sharing options...
dagabu Posted April 19, 2011 Share Posted April 19, 2011 Black match to the top for a quick launch, dont use piped match to the top, it can crack the fuel grain. Link to comment Share on other sites More sharing options...
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