AdmiralDonSnider Posted August 28, 2009 Posted August 28, 2009 (Assuming that "Rocketry" deals with model rockets mainly, I´m posting here...) I´m currently collecting and reading information about core burners, as I want to get started with making my own rockets soon. Sources like Hardt´s Pyrotechnics contain a great deal of useful and detailed information when it comes to the design of one´s own tooling. However, I´m still irresolute about which size of rocket motor/tooling I should choose, as I don´t know how much payload the different sizes can lift. I´m planning to lift one, probably two inch bombettes with one type and anything up to 3" spheres and cylinders with another. What would be a good motor size to start out with: 4 oz., 8 oz., 1 lb. (american size)?
TrueBluePyro Posted August 28, 2009 Posted August 28, 2009 I think for a typical 3" shell you would need a 1lb rocket. For a 2" shell a 8oz rocket would do it. Can shells will be heaver then a round shell, so keep that in mind. Tho, im thinking you will need some good fuel for a end burner, i dont have alot of expirience with end burners, im sure it would work, with some testing. Are you making the tools your self?
nick2354 Posted August 28, 2009 Posted August 28, 2009 [I Would say 1lb. According to passfire.com they can lift a 4" round shell.
dagabu Posted August 28, 2009 Posted August 28, 2009 [I Would say 1lb. According to passfire.com they can lift a 4" round shell. Benzo end burner? Yes, straight BP end burner? I don't know... Ill press one tonight and post the results. I use a glue bottle I filled with expanding foam, weighs 4oz. Great 2" dummy load.
AdmiralDonSnider Posted August 28, 2009 Author Posted August 28, 2009 (edited) Just in case there´s been some confusion: I´m planning to make core burner rockets, that show a perforation for about six-sevenths of the powder core. In this case the fuel is handmixed and based on BP ingredients, but not meal powder. I consider it an advantage if I don´t have to use mill-processed BP; furthermore the design - though hardly if ever found in consumer fireworks - has a good reputation regarding beauty and lift heights. What´s a good size to start out with in case of payload weights up to 100 grams? 1 lb (american) seems a bit overkill here, and this motor is already an 3/4" I.D., which is larger than most consumer motors I´ve seen so far. Thank you! Edited August 28, 2009 by AdmiralDonSnider
Mumbles Posted August 28, 2009 Posted August 28, 2009 3/4" will definitely do it. I bet you could get away with a 5/8" rocket for 100g. Obviously testers should be done before firing live material. I know you want to stay away from milled powder, but if your motors are having trouble getting the payload up, you could always juice the propellent up to get a bit more thrust.
Zmuro Posted September 4, 2009 Posted September 4, 2009 Could 1lb whistle rocket carry 300g shell? I'm using pusher core tooling from creagan site.
Aneantis Posted September 4, 2009 Posted September 4, 2009 I did 250 grams on a 17mm whistle, that was an oxy whistle. It did the job but i'm not sure about 300 grams.
fredjr Posted September 4, 2009 Posted September 4, 2009 Recently did a 732g 5" ball shell on a 3/4" id x 4.5" NaSal whistle rocket. http://www.pyrobin.com/files/3-4%20tooling.jpghttp://www.pyrobin.com/files/5%20ball%20on%203-4.jpg
KruseMissile Posted September 6, 2009 Posted September 6, 2009 wow! I loved that salute one! great job!
psyco_1322 Posted September 10, 2009 Posted September 10, 2009 I do remember I tested a 4oz nozzle-less and was able to lift 140g. I can't remember how far it went, but it lifted. With a nozzle, it might be ok. Every time I try flying a 3" ball (~130g) on a 4oz bp motor, they end up close to the ground. Most of the time its do to something I did to the motor, like super slow delay that doesn't work well in tubes, or adding enough mineral oil to make it chuff. Cool chuffing rocket and cool shell header was not able to be achieved in one engine. But a 100g payload should be no issue with a 4oz (1/2") core burner. If its a whistle rocket...different story...they will fly 3"s all day to nice heights. A 4oz whistle will throw a 1lb+ header to about tree height, might be good if you like your 4" salutes low. I haven't missed with 8oz rockets yet...they are in the works as soon as I get metal in to machine tooling. A 1lb bp core burner should fly 4"s no problem, same goes for the whistles. The whistles might even put up a 5" shell if its a nice motor....(oh I see fredjr already tried.) Aneantis,If your motor flew 250g, it should be able to do 300g. With a spindle around the range of 9mm wide and 90mm long, you should be good to go.
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