Mumbles Posted October 30, 2007 Share Posted October 30, 2007 That will be fine. To do it, you boil the alcohol outdoors on an electric heating plate, or in a basin of boiling water. It boils around 78C I believe. You then start adding shellac until it will not dissolve any longer. I believe the solutions are around 10%. Kentish states 1/2oz shellac to 5oz alcohol, which is 10%. I believe that amount of shellac will dissolve in ethanol at room temp, but I've heard that boiling it improves the adhesiveness. Actually he states to let it dissolve over night, and then boil it. Link to comment Share on other sites More sharing options...
mormanman Posted October 30, 2007 Share Posted October 30, 2007 Well, mumbles they don't have the size so I guess I'll have to look for a dowle of some sort and roll it myself. I hate this shell so much. It takes to damn long and if it doesn't work I'll cry. Link to comment Share on other sites More sharing options...
Mumbles Posted October 31, 2007 Share Posted October 31, 2007 Yeah, of course they don't. No one has any reason to make shells of those sizes. So, why do you want to considering you live in a place where pre-made mortar tubes, and all the supplies to build shells are readily available? It seems you already have a shell made. Why would you make a shell with no mortar from which to fire it from? Link to comment Share on other sites More sharing options...
hst45 Posted October 31, 2007 Share Posted October 31, 2007 mormanman, if you've made a shell of 3-1/2" diameter and are looking for a tube from which to launch it you might check out a printing company. Near my work I have a printing company that regularly discards 3-1/2" I.D. spiral-wound cardboard tubes. I reinforce these with half a dozen layers of kraft-paper and they make fine mortars. True, 3-1/2" is a bastard size, but since I make my own hemis it's not a problem. If you can't find these locally, PM me and I'll send you a length or two. Link to comment Share on other sites More sharing options...
asilentbob Posted October 31, 2007 Share Posted October 31, 2007 He posts a lot with little text in his messages instead of a little with a lot of text. (The more text you type (and clearly) the more likely that you wont have to post again to try to explain something) What is the actual outer diameter (OD) of your shell mormanman? Link to comment Share on other sites More sharing options...
mormanman Posted October 31, 2007 Share Posted October 31, 2007 The real O.D. turned out to be 3 1/4" spiked and everything. Anyway, I already made a mortar out of a 4" I.D. pcv pipe. Don't worry I'm not using the pipe to shoot the shell I just used it a mold. The shell fits snuggly so it should go about as high as I want it to. I would also like to know a website that would teach different methods of spiking. Link to comment Share on other sites More sharing options...
Mumbles Posted October 31, 2007 Share Posted October 31, 2007 What did you use as a former if you got that size of shell? It must have been almost 3" wide already. Shells will gain around 3/16" on either side from a normal spiking and pasting job. For a normal 3" shell, I would suggest a 12oz beverage can. I am also a fan of 12oz Renu contact solution bottles. They may have recently changed their design though. A soda can will definatly do it though, they are 2.55" OD. I don't mean to be pessimistic, but it may be worth your while to get a standard sized mortar, take apart the shell you have an remake it in a normal size. I assure you if you ever want to compete at the PGI, they won't have odd sized guns like that. I think they have 7" guns. If you want to go off the wall, try those. 6 1/4" former for the canister. Link to comment Share on other sites More sharing options...
mormanman Posted October 31, 2007 Share Posted October 31, 2007 I used a 3" pvc pipe as the former but the mortar should work. I may have to reinforce the mortar though. Link to comment Share on other sites More sharing options...
Mumbles Posted October 31, 2007 Share Posted October 31, 2007 If you used 3" PVC as the former, it should fit into a normal 4" ID mortar. I'm not suggesting using it, but it should slide down the 4" PVC you have. If not, you're doing something very wrong. 3" PVC is 3.5" OD almost exactly. 4" PVC is 4.5" OD. If you are gaining a full inch, there is something not right. http://www.harvel.com/pipepvc-sch40-80-dim.asp On an aside. If anyone has any spare 2.5 or 3.5" PVC around, please send me a pm, I'd be interested in some. Specifically the 3.5", I can't find it anywhere. Link to comment Share on other sites More sharing options...
mormanman Posted October 31, 2007 Share Posted October 31, 2007 Mumbles, I formed the can out of a 3.5" OD pipe and the mortar was formed out of a 4" ID pipe so the shell is 3.75 " and a 4" mortar. Thanks for all you guys input though. Whenever me and deadman can go shooting I'll submit it to the compitition. Link to comment Share on other sites More sharing options...
Mumbles Posted November 1, 2007 Share Posted November 1, 2007 To me "forming out of a 4" ID pipe" means you wrapped paper or what not around the outside of said pipe. That is not a 4" mortar if that is what you did. If you're actually using a pipe that is 4" ID, you really need to be more clear. Link to comment Share on other sites More sharing options...
mormanman Posted November 1, 2007 Share Posted November 1, 2007 I'm sorry, I have trouble with that as you all know. Anyway, I rolled the tube inside the pipe. BTW, how would one carbonate candy. Link to comment Share on other sites More sharing options...
oskarchem Posted November 1, 2007 Share Posted November 1, 2007 Hey, A friend gave me this idea: instead of using wooden sticks for rockets he said "Why don't you use a metal rod planted into the ground, and stick a plastic straw onto the rocket and pass it through the rod..." Ithaught about it but since I'm in the the hobby for only 1 and a half years I would need to get some info on that before trying. Link to comment Share on other sites More sharing options...
NightHawkInLight Posted November 1, 2007 Share Posted November 1, 2007 You would not get nearly as straight of flights as you do with a stick. Model rockets only get away with this because they are perfectly balanced and have fins. Unless you feel that you can put fins on your rockets easier than a stick I wouldn't expect great results. Sticks are used because they are an extremely fast and easy way to stabilize. If you do want a stick free rocket to save some money you could always try stinger missiles. Never seen or made them more than 1" in diameter but I suspect they'd work. Link to comment Share on other sites More sharing options...
Tweetybird88 Posted November 1, 2007 Share Posted November 1, 2007 What exactly is a "STEVE LADUKE'S HYBRID-UNIVERSAL ROCKET KIT" Can it be used to make any kind of rocket? I don't quite understand the description. Link to comment Share on other sites More sharing options...
hst45 Posted November 1, 2007 Share Posted November 1, 2007 Why don't you use a metal rod planted into the ground, and stick a plastic straw onto the rocket and pass it through the rod..."NightHawk is right, you need either fins or a stick to stabilize a rocket, but I do remember hearing about an idea someone once had to glue a ring of straws around the circumference of a motor. The theory was that the air rushing through the straws would direct the rocket and offer even less weight and drag than a stick. i can't recall if he actually tried it, or just theorized about it, but seeing as I have lots of time on my hands now I think I'll try that. Report to follow....... Link to comment Share on other sites More sharing options...
Tweetybird88 Posted November 1, 2007 Share Posted November 1, 2007 Why don't people use fins on their rockets? After all the labor people put in why wouldn't they go the extra mile to ensure it pays off? Link to comment Share on other sites More sharing options...
NightHawkInLight Posted November 1, 2007 Share Posted November 1, 2007 It takes more precise work to get fins to work properly. It is actually much easier to get a reliable flight with a stick than it is with fins. Link to comment Share on other sites More sharing options...
mormanman Posted November 1, 2007 Share Posted November 1, 2007 Why don't you use a metal rod planted into the ground, and stick a plastic straw onto the rocket and pass it through the rod..."NightHawk is right, you need either fins or a stick to stabilize a rocket, but I do remember hearing about an idea someone once had to glue a ring of straws around the circumference of a motor. The theory was that the air rushing through the straws would direct the rocket and offer even less weight and drag than a stick. i can't recall if he actually tried it, or just theorized about it, but seeing as I have lots of time on my hands now I think I'll try that. Report to follow....... That doesn't sound like it would work unless you were to aim the bottom of the straws outward. The reason I say this is if the straws were there the air would just go straight through and if the air did that then whats the difference between straws and no straws? If I'm wrong please tell me. Link to comment Share on other sites More sharing options...
crazyboy25 Posted November 1, 2007 Share Posted November 1, 2007 would it be OK to pour my diluted waste sulfuric acid down my PVC drain im afraid it may corrode the PVC. Link to comment Share on other sites More sharing options...
mormanman Posted November 1, 2007 Share Posted November 1, 2007 It shouldn't, I don't see why not. I mean its just drain cleaner so the worst it should do is........clean it (am I right). Crazyboy, I would seek more oppinions before though b/c I might be wrong but I don't think I am. Happy trails. Link to comment Share on other sites More sharing options...
Tweetybird88 Posted November 2, 2007 Share Posted November 2, 2007 What mormanman is saying is true. Straws would be useless if they don't change the air flow at all. Link to comment Share on other sites More sharing options...
NightHawkInLight Posted November 2, 2007 Share Posted November 2, 2007 Not true, if the straws were long enough it would force the air to travel through and past them in a straight line, therefore making the rocket fly straight. It is the same concept as fins, although I think that unless the straws are very long they will do little to hold a rocket on its course. Fins that are wide enough to displace a lot of air work better than narrow ones, but narrow ones still function to some extent. Link to comment Share on other sites More sharing options...
asilentbob Posted November 2, 2007 Share Posted November 2, 2007 Drag and weight from the stick favors a vertical flight... ex... if the rocket takes off and starts going nearly horizontal, the drag from the air against the stick coupled with the sticks weight will actually direct the rocket to correct itself a bit and make it go up more. If the rocket takes off and starts going a 45degree angle the drag from the air on the stick coupled with the weight of the stick will direct the rocket to go more vertical. You gotta remember that once the rocket has took off... it has burnt a significant weight of fuel... so now the stick end is heavier than the motor end. Now with fins alone... if the fins are no aligned right the rocket will straight up just flip over... This rarely happens with stick stabilized rockets... A stick that isn't aligned perfectly generally causes some funky twisted flying... but still favoring vertical flight... A stick that is too short/heavy to balance out the weight of the motor also can make for some funky flying. A spirally assent generally. You gotta consider all the forces acting on the rocket. Link to comment Share on other sites More sharing options...
mormanman Posted November 2, 2007 Share Posted November 2, 2007 Not true, if the straws were long enough it would force the air to travel through and past them in a straight line, therefore making the rocket fly straight. It is the same concept as fins, although I think that unless the straws are very long they will do little to hold a rocket on its course. Fins that are wide enough to displace a lot of air work better than narrow ones, but narrow ones still function to some extent.Also, the straw are plastic right. The rockets hot right (not trying to be mean). So take the rockets tail into constiteration. The plastic melts and the airflow stops. So what happens next, the straws turn into more drag than just one stick alone. So all and all the straws are to much trouble than one stick. Unless of course the straws are made of wood. Again correct me if I'm wrong. Link to comment Share on other sites More sharing options...
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