al93535 Posted April 20, 2006 Share Posted April 20, 2006 I am suprised there is no BP rocket thread here yet. So here it is. I have been making a few BP end burning rockets lately. I roll the tube 5/8" ID by 3 and 1/2" long. Although my newest ones are 4" long. I ram a conical shaped end plug, ram my fuel and ram another clay plug. After that I drill a 1/8" nozzle. These are end burning rockets. The first picture is a pic of my rocket after it was fired. This was just a test to see what I can lift. The dummy header weighs 84 grams. The video of that test is right after the picture. I used 90% BP and 10% 325 mesh atomized al for fuel. I didn't get much of a tail. So I am now trying 80 mesh mgal 5%, and medium al flitters 5% with 90% BP. The third pic is my newest working header rocket. It has 12 1 gram TI timed reports in it. The head weighs 75 grams. I have two more identical rockets on the way; a conkling blue, and ruby red. http://img.photobucket.com/albums/v242/al93535/rocket.jpg http://www.apcforum.net/files/MVI_0153.AVI http://img.photobucket.com/albums/v242/al93535/rocket58.jpg After these I will try adding ball shells and maybe multi breaks to the rockets. I might also try a bigger rocket, from 3/4" ID to 1" ID tubes. Hopefully I will have more video's of these rockets soon! Ooops, maybe someone wants to move this to the rocket area. Sorry! Link to comment Share on other sites More sharing options...
[w00t] Posted April 20, 2006 Share Posted April 20, 2006 Umm? theres a whole section dedicated to rockets. Link to comment Share on other sites More sharing options...
Von Bass` Posted April 20, 2006 Share Posted April 20, 2006 before the thread gets moved, did you mill your BP? Would the rocket be too fast if i used milled BP and CATO? thanks nice rockets btw! Link to comment Share on other sites More sharing options...
BigBang Posted April 20, 2006 Share Posted April 20, 2006 For end burning rockets in particular, milled BP is what should be used. Due to the low burning surface area, you want a propellant that will burn "fast" to maximize thrust. If you use greenmix, usually enough lift won't be produced, so you can't have a larger payload. Link to comment Share on other sites More sharing options...
al93535 Posted April 20, 2006 Author Share Posted April 20, 2006 I use the fastest willow meal I can make. I milled for the normal time that I use for all my BP, 4 hours. Link to comment Share on other sites More sharing options...
Von Bass` Posted April 21, 2006 Share Posted April 21, 2006 Right thanks a lot, my BP is blasa milled for 4 hours so its fairly fast. My tubes should have dried out know so i think i shall try making some rockets. Last questions I promise, could I use a roman candle delay mix for the delay between the burst? And how safe is it to drill out the cores of rockets if i use BP and Al? I have 300 mesh spherical aluminium of inoxia. Thanks for the help Link to comment Share on other sites More sharing options...
Mumbles Posted April 21, 2006 Share Posted April 21, 2006 I would drill it slowly, and if at all possible, by hand. One thing to note, if you are making core burners, use a slower mix. Since you seem to want to use BP, make an end burner. This means only drill a little bit into the BP. I also suggest just making the rocket component first before adding any sort of effect. Link to comment Share on other sites More sharing options...
Von Bass` Posted April 22, 2006 Share Posted April 22, 2006 Right thanks for that. I decided against adding a header until I am profficent at making these rockets! I hand drilled a 2/16th hole about halfway into the core. I balanced the nozzle using the finger method (see pic) and added a peice of visco. The entire thing weighed exactly 10g... maybe too light? Now all i need is for it to be dark The rocket balancing on my finger: http://i81.photobucket.com/albums/j207/VonBass/IMG_0003.jpgThe rocket showing the nozzle: http://i81.photobucket.com/albums/j207/VonBass/IMG_0004.jpg Link to comment Share on other sites More sharing options...
Givat Posted April 22, 2006 Share Posted April 22, 2006 I will be very interested to see your ruby red rocket, and if you can say how you make it it will be great. This formula warked for me only in stars, never was fast enogh as a rocket.You use it for core less rocket? Link to comment Share on other sites More sharing options...
al93535 Posted April 23, 2006 Author Share Posted April 23, 2006 I am sorry. I meant conkling blue and ruby red stars in the header. I only use BP in the rocket engine. Link to comment Share on other sites More sharing options...
Givat Posted April 23, 2006 Share Posted April 23, 2006 Ohh disappointing Link to comment Share on other sites More sharing options...
al93535 Posted April 24, 2006 Author Share Posted April 24, 2006 From the competition thread: Ok here is my first submission, with more to come. This is a 6 ounce bp end burning rocket with my variation of ruby red stars.Stats:engine:41 grams1/8" nozzle4 inches long5/8" ID Header :83 grams2" cylinder headerfused with visquick with no other delay The stick was 32".. No attempt to balance this rocket was made. I learned is is not needed. In the video the rocket heads into the wind, its not from the balance on the stick 2smile.gif See my test video for that. Total rocket weight 136.4 grams (with a 12.4 gram 1/4" diameter round stick) Pre firing picture: http://img.photobucket.com/albums/v242/al93535/rocket58.jpg Video: http://www.apcforum.net/files/6OZrubyred.wmv And rocket: I launch from an old metal tube from a ripped up tent. Just push it into the dirt and I am ready to go. Link to comment Share on other sites More sharing options...
Von Bass` Posted April 24, 2006 Share Posted April 24, 2006 Thats a beauty! I especially love the sound of rockets Link to comment Share on other sites More sharing options...
Givat Posted April 24, 2006 Share Posted April 24, 2006 I ca't belive this little motor, with no core, can lift so much with it. amazing. And with my variation of ruby red stars. what is the different between the original comp and your stars? Link to comment Share on other sites More sharing options...
Mephistos Minion Posted April 24, 2006 Share Posted April 24, 2006 I have 3/4" tooling here, I just need to roll some tubes and such before I can be making some rockets. I heard somewhere that 3/4" rockets can lift something like 180g? This is for a core burner (tooling is from www.pyrotooling.com so its a core burner). Has anyone had experience with 3/4" rockets and can enlighten me? EDIT: Just rolled a beast of a tube; 3/4" ID x ~7". Walls on it are around 4mm. Sorry about the shithouse pics but my digital camera is out of arms length, therefor I can't be arsed getting it. http://img.photobucket.com/albums/v466/mephistosminion/Picture237.jpg http://img.photobucket.com/albums/v466/mephistosminion/Picture236.jpg Link to comment Share on other sites More sharing options...
[w00t] Posted April 24, 2006 Share Posted April 24, 2006 O_o fluffy hair there. Looks pretty good (the tube that is) Link to comment Share on other sites More sharing options...
Givat Posted April 25, 2006 Share Posted April 25, 2006 I just can't anderstand how you can lift so much with this endburning rockets I made today some test for my tools for 1/2" core burning rocket and 3/4" for fountain/driver. The first test was a 1/2"rocket. 4.5 m"m spindle DIA (3/8*ID), 3.6 c"m long (3*ID). I put a pyload of 25 grams of dirt on top of it to chack it's lifting power. http://img181.imageshack.us/img181/6107/first05inchrocket25grpayload5v.th.jpghttp://www.apcforum.net/files/first0.5inch...25grPayload.wmv It fly to about 15 meters I guess. but it's dont very good if I want to lift with it stars and not only flash (they can come back to the ground in this height).Does 25 gram payload for a 1/2" core burning rocket is too much? Also I made a end burning 3/4" rocket, spindle DIA IS 5 m"m (1/4*ID) and about 21 m"m long (just to pass the plug). this rocket did fly, but only to about 1.5-2 meters and came back to the ground:http://img283.imageshack.us/img283/5527/075inchendburningnopayload6fa.th.jpghttp://www.apcforum.net/files/first0.75inc...g_nopayload.wmv Is this a balancing problem? (I dont balance my rocket, never.) or does it got not enogh thrust? Thanks. [edit]More pics of the rockets:1/2" autopsy:http://img283.imageshack.us/img283/6668/05inchautopsy7ni.th.jpg 3/4" autopsy:http://img283.imageshack.us/img283/3607/075inchautopsy6lf.th.jpg Link to comment Share on other sites More sharing options...
Mumbles Posted April 25, 2006 Share Posted April 25, 2006 The nozzle diameter on your 1/2" rockets is too large. The case is also not long enough. This would cause it to no provide a lot of thrust, which could explain the low height. What fuel did you use in each of these? It may also have an impact Link to comment Share on other sites More sharing options...
Givat Posted April 25, 2006 Share Posted April 25, 2006 The 1/2" width is from passfire The fuel is 4hours milled pine BP. Link to comment Share on other sites More sharing options...
Mumbles Posted April 25, 2006 Share Posted April 25, 2006 Passfire states 3/16" not 3/8" nozzel width. Link to comment Share on other sites More sharing options...
Givat Posted April 25, 2006 Share Posted April 25, 2006 3/8 the ID.I also wrote 4.5 m"m for clarification. (wich is 0.2 m"m smaller than the one passfire used) Link to comment Share on other sites More sharing options...
Mumbles Posted April 25, 2006 Share Posted April 25, 2006 Sorry, I got confused by the way you said it. I thought the nozzle was 3/8". Your casing is still about 20% too short though. Link to comment Share on other sites More sharing options...
Givat Posted April 25, 2006 Share Posted April 25, 2006 here a drawing of what I think will be the rocket with the most thrust: http://img271.imageshack.us/img271/2694/scatchrocket6lq.jpg All the fuel uper than the spindle got the same thickness as the fuel in the sides of the rocket. (the drawingis much more understood) So if this true my rocket had the most thrust I can get from it with this spindle. Is this sure this is the best measurements if it was at passfire? Link to comment Share on other sites More sharing options...
Mumbles Posted April 25, 2006 Share Posted April 25, 2006 I understand the drawing. Out of curiosity, what makes you think that will provide the most thrust? The general convention is to put a solid increment equal to 1 to 1.5x the ID of the tube. This is roughtly 2-3 times what you have in your drawing. The size of rocket you are making, actually a 3/8" or 2oz rocket is a weird one. It uses a shorter tube, and a different size nozzle than all the other BP rockets. My best advice would be to launch some without payloads. This will tell you if it is your rocket, or just the weight of the payload. Link to comment Share on other sites More sharing options...
brainfever Posted April 25, 2006 Share Posted April 25, 2006 Just thought I should share my work-pony: The rocket engine is made in a 50-55 mm long electrical PVC tube; 14mm ID. First, a 15 mm bentonite clay nozzle is pressed.Then 25 mm of 70 KNO3 / 30 BBQ-C (milled) is pressed.After that a 10 mm end plug is pressed. A core is drilled with a 3 mm drill bit for a length of 35 mm (allmost completely trough the BP). These rather small engines are used in a stick type rocket using a 500 mm plant stick taped to them.Without payload, these go completely out of sight and are rarely recovered. I've tested with dummy payloads up to 25 grams (estimate heights): 1 gram => 50m-70m at least2,5 grams => ~50m5 grams => ~30m10 grams => 15m25 grams => 5m Link to comment Share on other sites More sharing options...
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