MinamotoKobayashi Posted July 15, 2017 Posted July 15, 2017 (edited) Hello forum. I'm very proud to introduce You my last creation: a massive 450+ grams rocket with titanium sponge and hard PVC head + nozzle. I have done many fails before to refine my new rocket motor, because it is not so simple to lift so much weight almost instantly without a CATO. Well, here is the full detailed review. A 45mm diameter, 175mm lenght cardboard tube. This is not a tube made specifically for rockets. Originally it was a long tube where there was a rolled cloth: Extremity reinforced with gummed tape (water activated): All the tube reinforced with gummed tape. I wrapped the tube with 6 layers of gummed tape, but every coil overlap the precedent coil of about 1/2 of its width, so I obtained the equivalent of 12 layers: 35mm diameter, 20mm thickness machined head cap and nozzle (from a hard PVC bar): Spreading some very strong bicomponent epossidic glue on the inside top walls of the tube: Applying some tape over the inside nozzle hole to avoid spilling liquid incandescent compound during the compacting process: Nozzle pressed and glued: Applying ant tightening an excellent Panduit stainless steel band with a special clamp: 130 grams of potassium nitrate, 70 grams sucrose, 2 grams iron oxyde and 6 grams of titanium sponge 450-1000µm. I used a heavy and thick cast iron cooking pan over an electric cast iron plate to avoid dangerous hot spot that could accidentally ignite the compound: Dissolved powders adding enough distilled water: Cooking the compound at medium heat (150 °C): The compound is near to be ready. It is important to stir often the compound for safety reasons and to obtain a homogeneous paste: Compound dried and melted. Now the paste is ready and extremely flammable. Max care is now necessary: Packing the compound with a PVC bar. The fit is perfect, so no compound can get off the sides. To reach optimal results it is necessary to pack the compound not all together, but the equivalent of a tea spoon every time. After every spoon I will apply a pressure with the weight of my body (95 KG). In that way every part will be well compacted over the previous one: Packed and cold pressed compound: Glued and pressed strong PVC cap: Appying another Panduit stainless steel band to firmly lock the head: Since the compound will be ignited from the inner center of the rocket, I created a 6.5mm diameter straw wrapped with many turns of thin aluminum foil. In that way the fuse will not perforate the straw and will ignite the compound exactly where I want: Curved 3mm diameter, 5 cores high quality fuse. The fuse will cling well inside the compound hole: Dressing the rocket in great gala cloth: Refine the head part: Drilled an hole in the compound with the same hole diameter of the nozzle (10mm) until reaching the middle of the rocket. Inserted the modified straw with the fuse inside. Locked the straw with some pieces of cotton to avoid possible expulsions during burning. Glued the rocket over an appropriate long stick: WOW .. it is a heavy rocket: The fantastic launch during afternoon: https://www.youtube.com/watch?v=x48LE5OB7uE The fantastic launch during night: https://www.youtube.com/watch?v=GUS0zEhAjRY I will assure You that the departure hiss has been at least 10 times as intense as the cell phone was prone to capture! This was another great project successfully ended. Next week I will start another rocket project, as usually. The mad people never sleep Stay tuned on this channel my dear friends! Edited July 16, 2017 by MinamotoKobayashi 2
stix Posted July 15, 2017 Posted July 15, 2017 Nice work there MK. I especially like the night version. The added titanium sponge has worked well and much better than straight KNSU which pretty much has no tail.
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