You don't need pistons, I have a working cannon on my xbox server. If you build it like most of the youtube videos you need to punch the end tnt about 2 seconds after you flip the lever and the other four drop.
Additionally srghg if you want the cannon to fire without having to punch the front tnt block I can post a diagram on how to build/ wire it to shoot with a single flip of a lever.
Out of interest, is the situation affected at all by what material you use? i.e would making the barrel from obsidian matter?
Can it start a fire/ damage the surroundings? My boat is wooden
Can the range be affected by using more or less TNT in the water stack?
You can make the barrel out of obsidian and you should for a dry cannon. At least, if you want to fire it more than once..... You could also use obsidian under wood to make a hidden structure that's strong enough to stop you from having to rebuild your ship on a misfire......
The wet cannons I've made usually just use stone. It's blast resistant enough that if I goof up, the trough doesn't have to be rebuilt. This isn't an issue on versions > 1.6.6, but in the current version you can't move TNT if you place it wrong - be warned.
In my experience, the more stacks of TNT just make for a better chance that the fired shot goes farther, but it won't necessarily make it go any further than fewer stacks. The idea is that the bottom charges go off just before the shot charge - TNT that isn't primed has no physics and won't be launched. The shot has to be primed in order to go anywhere, but the TNT count down is randomish (1-3 seconds, I think?). Using more charges gives you a better chance of igniting the shot and having a stack explode right at the moment the shot is physics enabled. It's kind of an art with a dash of luck......
To get an idea of how to launch an entity, you can go load up on mushroom soup. Stand at the end of a wet cannon and jump up and down - if timed right, the blast should launch *you*. That's the same timing you want the shot charge to have when it becomes ignited.
Fun mostly. I build up a big wool target then shoot away. Pointless... yes, fun... well you shoot tnt through the air and blow something up so... yes
You can make the barrel out of obsidian and you should for a dry cannon. At least, if you want to fire it more than once..... You could also use obsidian under wood to make a hidden structure that's strong enough to stop you from having to rebuild your ship on a misfire......
The wet cannons I've made usually just use stone. It's blast resistant enough that if I goof up, the trough doesn't have to be rebuilt. This isn't an issue on versions > 1.6.6, but in the current version you can't move TNT if you place it wrong - be warned.
In my experience, the more stacks of TNT just make for a better chance that the fired shot goes farther, but it won't necessarily make it go any further than fewer stacks. The idea is that the bottom charges go off just before the shot charge - TNT that isn't primed has no physics and won't be launched. The shot has to be primed in order to go anywhere, but the TNT count down is randomish (1-3 seconds, I think?). Using more charges gives you a better chance of igniting the shot and having a stack explode right at the moment the shot is physics enabled. It's kind of an art with a dash of luck......
To get an idea of how to launch an entity, you can go load up on mushroom soup. Stand at the end of a wet cannon and jump up and down - if timed right, the blast should launch *you*. That's the same timing you want the shot charge to have when it becomes ignited.