User:King of the Internet

No-Bauxite Obsidian Production

Level 1 (Bottom)

    ║MM║
╔═══╝##╚═══╗
║++++++++++║
║++++++++++║
║++++++++++║
║++++++++++║
║++++++++++║
╚════OO════╝

Level 2

    ║<<║
╔═══╝CC╚═══╗
║..........║
║..........║
║..........I
║..........I
║..........║
╚════OO════╝

Legend

• = - Wall
• + - Floor [Obsidian ramp area] (see Operation)
• . - Space
• I - Water inlet floodgates
• O - Water outlet floodgates
• C - Space [Channel area] (see Operation)
• # - Floor [Retaining wall area] (see Operation)
• M - To magma pipe (No floodgates)
• < - Up stairs (Dwarf access)

Operation

1. Allow the magma to completely cover Level 1. Any depth will do.
2. Open the water inlet floodgates [I], turning Level 1's magma into obsidian.
3. When all the magma in the square area is turned into obsidian (the magma at [M] will still be magma), close the water inlet floodgates [I].
4. Open the water outlet floodgates [O] if the water is at greater than 3/7 depth on Level 2.
5. Have your dwarves carve ramps out of all the newly-formed obsidian except the obsidian in the retaining wall area [#].
6. Haul the obsidian to your dump or obsidian stockpile, and close the water outlet floodgates [O].
7. With all obsidian hauled away and no dwarves on Level 1, channel away the Channel area [C]. This will remove the retaining wall and allow the magma to flow into Level 1 again. Repeat at Step 1.

• Remember not to open the water outlet floodgates [O] when magma is covering level 1--you'll end up with magma somewhere you don't want it, and the lower outlet floodgates will deconstruct (unless you have bauxite mechanisms, in which case you don't have to use this design anyway).
• You don't have to wait for the water to completely drain and evaporate away to begin the process again. Magma flowing onto 1-deep water will simply "eat" the water, not produce obsidian. (However, the obsidian floor at [C] will have to be immediately re-channeled if it has water on it, because the water will fall onto the magma that just flowed there and produce obsidian again.)
• Supposedly, wooden floodgates (and pump components) will retain magma, but suffer heat damage and quickly fail. I've used green glass pump components and floodgates with no problems.
• Don't let the magma in until everything is in order!