genrege Posted July 12, 2012 Posted July 12, 2012 I've made a few bottle rockets now, most even worked quite well, with home made tubes, kitty litter clay nozzle/nose, visco fuse etc. This evening, I thought I'd try a "header". The only tooling I have are the aluminium dowels/drifts I use for forming the tubes and subsequently ramming in the compositions. I made the rocket nozzle as usual, rammed in some BP, then rammed a clay bulkhead between the propellant and the header. To pass the fire through the bulkhead, I drilled a 2mm hole at the edge, and stuffed in a short length of visco fuse. I then topped off with lightly rammed 10# BP and a sprinkling of 325# Al powder which I sealed with some tape. To make the nozzle, I drilled a 2mm hole through the clay and 3/4 the way into the BP to make a "core". Stuffed more visco into this to make the fuse. When I lit it it got about 5 feet into the air and CATO'ed :-( The post-mortem showed the bulkhead had been ejected out of the top of the tube and the nozzle was still intact. I guess that I need more clay in the bulkhead and/or ram it a bit harder? Also, what sort of header is reasonable for this type of rocket? I figured the BP/Al would make a nice white flash "or something" without the loud noise of a flash header (it's still at the early/experimental stage!) Hmmm, can I even re-use the tube and intact nozzle or should I make a new one and save me a bit of effort? If I was to add some of the 325# Al to the propellant, would I be able to ram it safely (Al dowel+hammer), drill the core safely, how would it perform compared to pure BP and would it make a nice exhaust trail? I'm also thinking of shortening the length of the core to provide a longer flight time (don't really want a really fast accelerating rocket and would prefer a more stately ascent). My BP is all 75/15/10, maybe I should try the 60/30/10 ratio I've heard some people use.
dagabu Posted July 12, 2012 Posted July 12, 2012 I've made a few bottle rockets now, most even worked quite well, with home made tubes, kitty litter clay nozzle/nose, visco fuse etc. This evening, I thought I'd try a "header". The only tooling I have are the aluminium dowels/drifts I use for forming the tubes and subsequently ramming in the compositions. I made the rocket nozzle as usual, rammed in some BP, then rammed a clay bulkhead between the propellant and the header. To pass the fire through the bulkhead, I drilled a 2mm hole at the edge, and stuffed in a short length of visco fuse. I then topped off with lightly rammed 10# BP and a sprinkling of 325# Al powder which I sealed with some tape. To make the nozzle, I drilled a 2mm hole through the clay and 3/4 the way into the BP to make a "core". Stuffed more visco into this to make the fuse. When I lit it it got about 5 feet into the air and CATO'ed :-( The post-mortem showed the bulkhead had been ejected out of the top of the tube and the nozzle was still intact. I guess that I need more clay in the bulkhead and/or ram it a bit harder? Also, what sort of header is reasonable for this type of rocket? I figured the BP/Al would make a nice white flash "or something" without the loud noise of a flash header (it's still at the early/experimental stage!) Hmmm, can I even re-use the tube and intact nozzle or should I make a new one and save me a bit of effort? If I was to add some of the 325# Al to the propellant, would I be able to ram it safely (Al dowel+hammer), drill the core safely, how would it perform compared to pure BP and would it make a nice exhaust trail? I'm also thinking of shortening the length of the core to provide a longer flight time (don't really want a really fast accelerating rocket and would prefer a more stately ascent). My BP is all 75/15/10, maybe I should try the 60/30/10 ratio I've heard some people use. Lots of things going on here, lets sort some of this out. First, what size are your rockets, ID and length? Why are you using a clay bulkhead? What kind and weight of a hammer are you using? How far is "3/4 the way up"? BP and Al will only make a spritzle kind off effect, pretty but little noise. You need tooling, drilling in rockets makes me cringe. If you are in the USA, PM me and I will see what I can do to get you a simple spindle and rammer gratis. Yes, shortening the hole will make an endburner, drilling a longer hole will make a core burner. You need a bigger nozzle hole for a core burner. No, don't reuse casings, especially the ones that failed. They have already suffered one shock from the bulkhead blowout and ramming. Just roll a new one. -dag
genrege Posted July 12, 2012 Author Posted July 12, 2012 Hi Dag, I'm in the UK, but I really appreciate the offer! I've only seen one set of rocket tooling here in the UK, and it seems pretty expensive (approx 60 USD). Why am I drilling the core? Read about this somewhere, probably on this forum. I'll desist as it seems like a bad idea!The ID is 8mm and the length is 50mm. I'm using a 16oz hammer and clay because, well, I thought clay would take the pressure (which it didn't!). 3/4 the way up would be about 30mm into the BP. So to make an end-burner, I'll hammer in some clay, drill my 2mm nozzle, cover the nozzle with tape, hammer in the BP, then hammer in more clay (as a bulkhead) before adding a header? Does that seem reasonable? Thanks
dagabu Posted July 12, 2012 Posted July 12, 2012 Hi Dag, I'm in the UK, but I really appreciate the offer! I've only seen one set of rocket tooling here in the UK, and it seems pretty expensive (approx 60 USD). Why am I drilling the core? Read about this somewhere, probably on this forum. I'll desist as it seems like a bad idea!The ID is 8mm and the length is 50mm. I'm using a 16oz hammer and clay because, well, I thought clay would take the pressure (which it didn't!). 3/4 the way up would be about 30mm into the BP. So to make an end-burner, I'll hammer in some clay, drill my 2mm nozzle, cover the nozzle with tape, hammer in the BP, then hammer in more clay (as a bulkhead) before adding a header? Does that seem reasonable? Thanks Don't use a bulkhead, its a waste of time and weight IMHO. To make an endburner, just don't drill more then 5mm past the clay plug. I think your real problem now is ramming smaller increments. If you add just enough BP to make the fuel grain 5mm in height each time you ram fuel, the fuel grain will be a LOT stronger and less likely to CATO. Trust me, it's not your bulkheads that are failing, its consolidation of the BP. You have tooling for less out there in the UK. Tooling
nater Posted July 13, 2012 Posted July 13, 2012 (edited) I make a simple bag header for bottle rockets. The tubes I use are 1/4" by 2.5", which is a little smaller ID and little longer than what you are using. I do not use a clay bulkhead, and with rockets this small, there is little difference between using a nozzle and not using one. For the header, I made a former out of a 3/4" dowel rod with a smaller dowel that matches the OD of my tubes glued to the center of one end. I wrap a piece of kraft paper from a shopping bag 2 turns around the former dry leaving about an inch of paper overhanging the smaller dowel. Glue the outside flap down so you have a thin tube, and crimp the bottom edge around the smaller dowel. Once the glue is set (only a minute or two) remove the former and slip the header casing over the end of the completed motor tube. Tie off with a piece of twine, making sure the header is centered over the end. Pour loose BP or stick a piece of black match down inside so it is touching the end of the delay comp. Then fill with whatever heading / burst you want. Bits of flying fish fuse or micro stars work well with loose BP poured in the open gaps. Finish the header with a triangle fold at the top, attach your stick, fuse, and enjoy. They look like this: http://www.youtube.com/watch?v=hkpuCUdcBl4 edit to add: As always, there are better instructions out there, and need to give credit where credit is due. I got the inspiration here, and scaled down the technique to work with the SBR kit. Edited July 13, 2012 by nater
dagabu Posted July 13, 2012 Posted July 13, 2012 Great rockets Nate! Bag headers were my first shells and I had completely forgotten about them. -dag
nater Posted July 13, 2012 Posted July 13, 2012 (edited) Great rockets Nate! Bag headers were my first shells and I had completely forgotten about them. -dag Thanks. I will have something I am proud of in LaPorte, and probably a few for the launch Thursday night as well. I can't wait to build again. This dry weather put a damper on my plans for the summer. Bag headers aren't the only way, but they're fast and I think they look nice on small rockets. If you have the stars on hand, you can make these rockets start to finish in just a few minutes and fire them immediately. I also have some 1" plastic hemis from Pyro Direct where the fuse support fits snug into the ID of my 1/4" tubes. I think they're best for small salutes and don't have any video of them. Edited July 13, 2012 by nater
dagabu Posted July 13, 2012 Posted July 13, 2012 Thanks. I will have something I am proud of in LaPorte, and probably a few for the launch Thursday night as well. I can't wait to build again. This dry weather put a damper on my plans for the summer. Bag headers aren't the only way, but they're fast and I think they look nice on small rockets. If you have the stars on hand, you can make these rockets start to finish in just a few minutes and fire them immediately. I also have some 1" plastic hemis from Pyro Direct where the fuse support fits snug into the ID of my 1/4" tubes. I think they're best for small salutes and don't have any video of them. I have lots of green plastic hemis from dragon egg balls, Ill bring them to PGI for if you want them. -dag
pyrokid Posted July 13, 2012 Posted July 13, 2012 I put together some tiny bag shell headers for the fourth using glitter microstars. On the tiny bottle rocket scale, they looked like strobes. There is something fascinating about bottle rockets. I want to make a TR style fused display with them.
nater Posted July 13, 2012 Posted July 13, 2012 ^^ A rondelle with crossette shots as the timed salutes?
pyrokid Posted July 13, 2012 Posted July 13, 2012 ^^ A rondelle with crossette shots as the timed salutes? No, I want to try something challenging. Seriously though, I just want to attempt to replicate his method of matching effects and timing the flights of rockets on a small scale. Mainly as a novelty. Now that I've seen that vaccaluzzo video on pyro u, I am going to have to try some horsetail bottle rockets too!
dagabu Posted July 13, 2012 Posted July 13, 2012 No, I want to try something challenging. Seriously though, I just want to attempt to replicate his method of matching effects and timing the flights of rockets on a small scale. Mainly as a novelty. Now that I've seen that vaccaluzzo video on pyro u, I am going to have to try some horsetail bottle rockets too! Me LOVES horsetail! My daughter is crazy about long duration horse tail shells but actively BOO'S commercial ones as they are so short. TT is OK but likes the metals in horse tail better. I would love to see those shells PK. -dag
pyrokid Posted July 13, 2012 Posted July 13, 2012 Here you go: http://vimeo.com/45083890#at=0 Long hangtime willows start at 9:50 Horsetails at 10:20 The quality of their shells is outstanding! Would you guys say that the density of those charcoal tails is caused by lampblack? Or is it something else?
thechewy Posted July 14, 2012 Posted July 14, 2012 every time i try to make rocket with headers they explode the same way. But mines just blow out the header and continues the flight till all fuel is used up.. I live in louisiana,i also use a regular wooden dowl as a rammer and tube roller. Plus maybe a 2-3lb hammer. I tried making my own spindle but failed badly... So im just to point point of giving up on making rockets that have headers
Col Posted July 27, 2012 Posted July 27, 2012 (edited) Hi Dag, I'm in the UK, but I really appreciate the offer! I've only seen one set of rocket tooling here in the UK, and it seems pretty expensive (approx 60 USD). Why am I drilling the core? Read about this somewhere, probably on this forum. I'll desist as it seems like a bad idea!The ID is 8mm and the length is 50mm. I'm using a 16oz hammer and clay because, well, I thought clay would take the pressure (which it didn't!). 3/4 the way up would be about 30mm into the BP. So to make an end-burner, I'll hammer in some clay, drill my 2mm nozzle, cover the nozzle with tape, hammer in the BP, then hammer in more clay (as a bulkhead) before adding a header? Does that seem reasonable? Thanks If you have an electric drill and a file its pretty easy to make a set of 1/2" coreburner tooling with minimal effort. Short lengths of brass rod and aluminium tubing are cheap (ebay). Here`s a rocket made with the simple diy tooling shown in the pics. http://www.youtube.com/watch?v=SneqZSKnRA4 Edited July 27, 2012 by Col
Floydism Posted August 14, 2012 Posted August 14, 2012 That's a pretty little rocket! right up my street! I've got a thing for diddy bottle rockets! I've been looking around for 1/4" tooling for a little while, but if stuff is available it's way too pricey for what you get. I've been wondering about a homemade alternative but i'm not sure what sort of spindle dimensions are required for a 1/4" core burner? my tubes are 50mm long so i'd assume the spindle length required would be 40-45mm to give a suitable delay, but what about nozzle/core diameter?
Recommended Posts