JFeve81 Posted February 4, 2011 Share Posted February 4, 2011 Hey everyone. I'm relatively new to the pyro scene as well as APC. Well actually I made an account several months ago and just forgot about it. Either way my question is that I have a premade tube that I'm planning on turning into a cylindrical shell. It is exactly 3" in diameter. All the mortar tubes I've found are 3.05" ID. That's not much room. Do you think it would fit or be too tight of a fit if it can actually make it into the mortar? Or should I search for one that's slightly bigger. Say 3.5" if that's even possible to find. Link to comment Share on other sites More sharing options...
pyrojig Posted February 4, 2011 Share Posted February 4, 2011 (edited) I would say get a smaller tube to build your shells. How are you going to spike it or paste it for that matter if it is already that big to start with? Also what about the quickmatch or fuse that will ignite the shells lift? It needs to have a little room for these things. Edited February 4, 2011 by pyrojig Link to comment Share on other sites More sharing options...
Megabusa Posted February 4, 2011 Share Posted February 4, 2011 You don't need strong tubes for cylindrical shells. It is the spiking that gives the strength. You need to allow room for your shell to fit in the mortar after all this has been done. I would get your mortar tube first & then make your shell cases to fit. Link to comment Share on other sites More sharing options...
MrB Posted February 9, 2011 Share Posted February 9, 2011 Your 3" cylindric tube might work out for a 4" mortar. Not a great match, but over lift it slightly, and you should be able to get it up. After pasting and spiking your going to have a fair bit to much shell to fit a 3" mortar, but to little for a 4". Overlifting, is simply using more BP to launch it with.Another way would be to put something like a "plugg" between the lift, and the shell, but then you have to light the shell by fuse, if your not already planning to. This something could be, but isn't limited to, a 5" cardboard disc thats simply pushed down. It's not going to seal, which isn't the intention, it's just going to make the shell "larger" while still letting some gazes escape around the shell and make for a clean launch. The disc will be burnt, ugly, and smelling, you'll have to clean it away after the launch.B! Link to comment Share on other sites More sharing options...
KruseMissile Posted February 9, 2011 Share Posted February 9, 2011 Your 3" cylindric tube might work out for a 4" mortar. Not a great match, but over lift it slightly, and you should be able to get it up. After pasting and spiking your going to have a fair bit to much shell to fit a 3" mortar, but to little for a 4". Overlifting, is simply using more BP to launch it with.Another way would be to put something like a "plugg" between the lift, and the shell, but then you have to light the shell by fuse, if your not already planning to. This something could be, but isn't limited to, a 5" cardboard disc thats simply pushed down. It's not going to seal, which isn't the intention, it's just going to make the shell "larger" while still letting some gazes escape around the shell and make for a clean launch. The disc will be burnt, ugly, and smelling, you'll have to clean it away after the launch.B! Yeah, you can make it a sabot. Basically it catches the gases, and pushes the shell on top of it out of the gun. Just make sure you put a hole in the middle for the gases to go through and ignite your shell. Link to comment Share on other sites More sharing options...
Mumbles Posted February 9, 2011 Share Posted February 9, 2011 No sabot used in fireworks is tight enough to cut off the gases. It's not a bad habit to top fuse all canisters though. Link to comment Share on other sites More sharing options...
MrB Posted February 9, 2011 Share Posted February 9, 2011 I thought rather in the way of making a disc-shaped cardboard piece, about a inch wider then the mortar, and glue it between the shell and the liftcharge, and simply ram the thing down the mortar. As i understand it he has 1 of these 3" tubes, getting the stuff to make a proper sabot, for a one shot deal seams like a bit much effort to me.If you go with a cardboard disc and ram the whole thing down, it's still not going to be stopping the hot gazes and flames from passing, but it's anyone's guess as to how much, and where they will pass. thats the only reason i suggested lighting the shell by fuse. Generaly speaking topfused shells doesn't need to be fuse lit, they light just the same, as does comets, and what else you want to put on a shell. But in a improvised situation like this, it's a small effort to do, and makes sure you get it right. And as Mumbles says, you "should always" topfuse canister shells.B! Link to comment Share on other sites More sharing options...
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