oldspark Posted May 8, 2013 Posted May 8, 2013 Huh, I have doing some side by side comparisions and have found the low pressure pressed rocket work better then hand rammed every time. The rockets are heavier also do to more powder.
nater Posted May 8, 2013 Posted May 8, 2013 (edited) I also press my rockets to a high pressure, usually 7500 psi. I use good NEPT and PVC sleeves for support. Although, I cheated last night and pressed a 1/2" BP motor with no sleeve and no PtoF gauge. I fully expect the motor to CATO after looking at the wrinkles and bulges from a few increments. Later, I will press the same fuel in a nozzleless and nozzled design and test in my thrust stand. My experience has been you need the hottest BP to make a nozzleless rocket fly well. Yes, they fly with slower BP, but they won't lift much more than their own weight. Edited May 8, 2013 by nater
oldspark Posted May 8, 2013 Posted May 8, 2013 Just so you guys know I am just playing around and plan on pressing to higher pressures all the time, I just found it interesting they worked at all let alone better then hand rammed. One big thing in fireworks is just trying out things as long as you do them safely.
VikingPyrotechnics Posted May 8, 2013 Posted May 8, 2013 i love nozzleless rockets i think they have little bit more power?!Here some nozzleless rockets on video....you can see how much power they got http://www.youtube.com/watch?v=grxjLMZe4z0 http://www.youtube.com/watch?v=KsvxwPC-oGw Greets VP
nater Posted May 8, 2013 Posted May 8, 2013 I was told you only get about 1000 psi on the comp when hand ramming. With the rockets I have built and the lessons I have learned from the experts, the key to good rockets is pressing small increments to consistent and high pressures.
dagabu Posted May 8, 2013 Posted May 8, 2013 i love nozzleless rockets i think they have little bit more power?!Here some nozzleless rockets on video....you can see how much power they got Greets VP Stunning rockets and shells VP!! Bravo!
oldspark Posted May 8, 2013 Posted May 8, 2013 (edited) Viking-very nice rockets, looking forward to getting to that skill level. Edited May 8, 2013 by oldspark
psyco_1322 Posted May 9, 2013 Posted May 9, 2013 Hand mixed 75:15:10 will usually be plenty fast for nozzleless rockets. Yes you can mill the fuel, if you are really needing the extra power. If you are just lifting small salute headers or something relatively undersized for the rocket, why bother? You can mix in 2-3% wax as a binder and hand ram them, the fuel compacts very well and stays together. If you want an interesting rocket, add about 6% mineral oil into the fuel, you will get a wonderful BP chuffer. That much oil takes a lot of power out of your rocket so don't top it with anything heavy. Everyone asks about BBq charcoal, most stores have ACTUAL charcoal for sale right beside the BBQ briquettes. It's usually hardwood and not a fast burning charcoal but it works for most pyro stuff. It's usually named Royal Oak, or Cowboy Charcoal.
Oinikis Posted May 9, 2013 Posted May 9, 2013 (edited) well, lets get back to helping unflying guy. i have 1/2" 6/3/1 nozzled tooling, very satisfied about it. then i made 1 pound tooling, basicly i multiplied each dimension by 1.5. but i made the spindle 1.5 centimeter longer, becouse i wanted more power, but it blew up. it didn't cato, it blew somewhere in the mid thrust, so redline was crossed not by much. the point is, for me nozzle to cored fuel lenght ratio is 1:3. blowing in the mid thrust ratio is 1:4. so redline is somewhere between them. by the way, nozzle lenght is the same as the ID of the rocket, and the hole in it is 1/3 ID. what is your nozzle to cored fuel ratio? the top plug is just abit shorter. Edited May 9, 2013 by Oinikis
Mumbles Posted May 9, 2013 Posted May 9, 2013 That is a really weird way to phrase things. The "standard" of sorts for cored tooling has a spindle 7x the ID long. Typical commercial cored tooling for 1lb rockets will have a spindle length of 5.25" long, while the nozzle is at most .75" tall, and probably around .25" throat. This would be a 1:6 ratio by your metrics. You might want to try compressing the fuel better.
Oinikis Posted May 10, 2013 Posted May 10, 2013 (edited) maybe i should get a bigger hammer. i hit each increment like 15 times. my fuel is ballmilled, and burns a bit fast. but aren't these taller rockets pressed with a press? and is the fuell ballmilled? Edited May 10, 2013 by Oinikis
nater Posted May 10, 2013 Posted May 10, 2013 I have rammed 1 lb rockets with success, but all my issues went away when I started pressing them. I think a heavy rawhide hammer really helps get better results when ramming. Screen mixed fuel works well for me, many people mill their fuel too.
Oinikis Posted May 10, 2013 Posted May 10, 2013 (edited) i'm using used A4 paper to roll my tubes. it is way not perfect. i will buy some craft paper and wood glue for them. so would plugs will be more locked in if i use a stronger tube? i mean it would be harder to buldge the recesement. Edited May 11, 2013 by Oinikis
dagabu Posted May 10, 2013 Posted May 10, 2013 For pyrotechnic rockets, NEVER use solid plugs, when ejected in a CATO, they can be expelled at a terrific velocity. For this reason alone, I have abandoned the use of clay in my rockets and only depend on the fuel to plug the tube.
mikeee Posted May 10, 2013 Posted May 10, 2013 Anyone wanting to learn how to make whistle & strobe rockets along with the fuels.Ben Smith has some new tutorials on his website that are very well written and illustrated.http://www.firesmithtools.com
nater Posted May 10, 2013 Posted May 10, 2013 For pyrotechnic rockets, NEVER use solid plugs, when ejected in a CATO, they can be expelled at a terrific velocity. For this reason alone, I have abandoned the use of clay in my rockets and only depend on the fuel to plug the tube. There is the lawn dart hazard too, which is increased by solid clay plugs in the bulkhead. This was a very tame 1/2" BP rocket.
WonderBoy Posted May 13, 2013 Posted May 13, 2013 LTUPyro, Have success yet? What are the dimensions of your tooling? 60:30:10 is a pretty slow mix. What size increments are you using? I ram all of my 3/4" nozzled motors with great success. I like to use kitty litter with 3% oil added. I like that the kitty litter is granulated because it really bites into the tube. When ramming the bulkhead I loosen my tube support and ram hard enough to bulge the tube slightly, this really locks it in the tube. Oinikis, What size mallet are you using? For pyrotechnic rockets, NEVER use solid plugs, when ejected in a CATO, they can be expelled at a terrific velocity. For this reason alone, I have abandoned the use of clay in my rockets and only depend on the fuel to plug the tube. Dag, that seems quite sensationalist. When is a CATOing motor pointing at you? I am having a hard time imagining that happening, short of the launch tube falling over... WB
dagabu Posted May 14, 2013 Posted May 14, 2013 LTUPyro, Have success yet? What are the dimensions of your tooling? 60:30:10 is a pretty slow mix. What size increments are you using? I ram all of my 3/4" nozzled motors with great success. I like to use kitty litter with 3% oil added. I like that the kitty litter is granulated because it really bites into the tube. When ramming the bulkhead I loosen my tube support and ram hard enough to bulge the tube slightly, this really locks it in the tube. Oinikis, What size mallet are you using? Dag, that seems quite sensationalist. When is a CATOing motor pointing at you? I am having a hard time imagining that happening, short of the launch tube falling over... WB Not when you have a dent in your hatch from a buddies rocket that CATO'd 20' off the deck and shot the nozzle (Durhams) out and into my car. Come to PGI and I will introduce you to the guy that did it and the dent for clarification. Yes, we laughed about it but that was the last time i considered plugs of clay and started to go away from nozzles if possible. That and the obscene amount of lawn darts in Fargo my son and I found when collecting sticks the morning after the Rodeo on Thursday night. Of all the rockets that buried themselves in the muck, the ones that dug themselves the furthest were the ones with nozzles and plugs. Of the ones that were just laying on the ground sideways were all empty motor tubes. It would not surprise me in the slightest if the rules at PGI for the high flyers (whistle LWS) were to include stick breakers and no plugs.
LTUPyro Posted May 14, 2013 Author Posted May 14, 2013 LTUPyro, Have success yet? What are the dimensions of your tooling? 60:30:10 is a pretty slow mix. What size increments are you using? WB Yeah got some succes, now moving to nozzleles 75:15:10 and that works well for now, haven't tried to lift any shell except some small salutes, but going to try soon. My 60:30:10 for nozzleles is too slow to lift shell, but works well in nozzled. Thanks for help guys!
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