There's only a few levels on the map archive, and I'm exactly sure what you're planning to use the lava for. But here's what I do.
First, you have to breach the pipe safely. The easiest way to do this is to stand in a safe location - usually, dig a hole leading right up to the wall, then go one level above and channel out the last piece of wall. It's tricky here because the pipe is a uniform size, but you could go up to the top of the pipe and do it from there. Or you can just dig right into the pipe and have your miner run like the wind / take one for the team.
Second, you want to get the magma safely. This means filtering out the magma men and such. The best way to do this is to slightly modify the advice above - stop one extra unit early, and carve fortifications into the wall (has to be smoothed by an engraver first [d -> s], then carved [d -> a]). If you are going right into the pipe, you can engrave a fortification right against the pipe wall, but this time, your engraver better be ready to run.
Third, you need to route the magma to somewhere useful. It moves slowly, and if your opening is only 1 unit wide, it won't be able to fill a huge open space, because it will "evaporate" before it fills the room. That means a 1 or 2 wide hallway, and then a reasonably-sized room to fill with magma. You can do a snaking hallway to avoid this problem. The key is that you don't let it spread out everywhere. The room near the magma on level 65 of your map is too large - it probably won't fill. You can fix this with some constructed walls. Pretend like you are routing invaders through a maze of traps, and you'll have the idea.
Fourth, you place the forges and furnaces directly above the magma, and channel out holes. If you're looking at the keypad on your computer, magma forges need the "4" and "6" holes channeled out. The other magma buildings need the "8" key channeled out (keep this in mind when designing your magma "maze"). Once the magma reaches a depth of 4/7 (I think) they will start to work.
Fifth, save some of that magma! You will want to play with it for other purposes. I would recommend using two sets of magma-safe drawbridges, doors, or floodgates. One will go at the entrance to the magma forge area, because you will want to keep it at depth after it's full (i.e. you don't want to draw magma from there). The other should go in that same hallway leading up to the magma forge area, so that when you decide what you need magma for, you don't have to breach the magma pipe again - you've already got a resealable opening. Remember that both the door/bridge/floodgate and the mechanism on the door/bridge/floodgate needs to be made out of magma safe stone or metal. The wiki has a list of magma-safe materials
here.
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Topic: I need some advice on my fotress (Read 1187 times)